Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?

marv

Marv

If you are serious bake the transformer at low temperature in an oven before trying it again. Measure leakage between windings before attempting to use it again. It may take longer than 2 hours to get all the moisture out.

Once you hear a frying sound may be too late. Transformer may already have been damaged?

Norm

:Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:
:marv
:

Norm,
Thanks, but too late. Let it cook for a few mins, hoping it would dry out if water, but got worse. Out of the set, no load, draws 800-900ma, and frame gets hot. Primary measures 17.4 ohms. 6V winding .4ohms; HV winding 238 ohms. Similar FM tuner supply measures 20.4 ohms primary. Peeled off some of the paper, and no sign of water, so must be a hard short in primary. Is there authentic replacements for them, at a reasonable cost?

marv

:Marv
:
: If you are serious bake the transformer at low temperature in an oven before trying it again. Measure leakage between windings before attempting to use it again. It may take longer than 2 hours to get all the moisture out.
:
: Once you hear a frying sound may be too late. Transformer may already have been damaged?
:
:Norm
:
::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::
::marv
::
:

Marv

Might try looking through this list:

http://www.oldradioparts.com/2a23efl.txt

Norm

:Norm,
:Thanks, but too late. Let it cook for a few mins, hoping it would dry out if water, but got worse. Out of the set, no load, draws 800-900ma, and frame gets hot. Primary measures 17.4 ohms. 6V winding .4ohms; HV winding 238 ohms. Similar FM tuner supply measures 20.4 ohms primary. Peeled off some of the paper, and no sign of water, so must be a hard short in primary. Is there authentic replacements for them, at a reasonable cost?
:
:marv
:
:
::Marv
::
:: If you are serious bake the transformer at low temperature in an oven before trying it again. Measure leakage between windings before attempting to use it again. It may take longer than 2 hours to get all the moisture out.
::
:: Once you hear a frying sound may be too late. Transformer may already have been damaged?
::
::Norm
::
:::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::
:::marv
:::
::
:

Too bad.

As I'm sure I explained in all my earlier posts.
..I always remove power transformers before washing the chassis.

Everything else holds up fine... and it only takes a few minutes to pop the power transformer back in when the rest is dry.

You COULD also do it with the PT in ....but it just takes a much longer time to dry safely.

I have read about others washing radio chassis with water, and this has always struck me as fairly risky, compared to the relative benefits.
If I knew for a fact I could dry everything completely before any corrosion set in, then maybe.
I can not see washing anything with copper and paper winding in it.
For those that washed them and had good success, more power to you.

Paul
:

The flickering pilot, erratic current drain and excess heat was there before washing and just got worse afterward. Wonder if pulling the rectifier allowed the unloaded HV winding to exceed the breakdown voltage of the original corrosion/crud to final hard short?

marv

:I have read about others washing radio chassis with water, and this has always struck me as fairly risky, compared to the relative benefits.
:If I knew for a fact I could dry everything completely before any corrosion set in, then maybe.
:I can not see washing anything with copper and paper winding in it.
:For those that washed them and had good success, more power to you.
:
:Paul
::
:

You could get lucky if you take the bells off and see if there is evidence of arcing with the connecting wires to the windings. I've seen this many a time. Unless you have shorted or open windings, very carefully check all connections, replace the leads if needed, tape everything up with multiple layers of electrical tape, paint the bells while they're off, and you just might save this one. If there is a lot of charring and the windings are loose, then it's not really safe to proceed. Just an aside, with all windings disconnected from the set, and powered up, you could see if it still overheats. There's no harm in powering up an otherwise transformer in good condition with no load - but the output voltages will measure higher than they will with a load.

Just my 2 cents worth, but I would bet that a cycle trhough the dishwasher would exascerbate any corrosion that exists in the delicate windings of rf, if, and oscillator coils on an old set.

:The flickering pilot, erratic current drain and excess heat was there before washing and just got worse afterward. Wonder if pulling the rectifier allowed the unloaded HV winding to exceed the breakdown voltage of the original corrosion/crud to final hard short?
:
:marv
:
::I have read about others washing radio chassis with water, and this has always struck me as fairly risky, compared to the relative benefits.
::If I knew for a fact I could dry everything completely before any corrosion set in, then maybe.
::I can not see washing anything with copper and paper winding in it.
::For those that washed them and had good success, more power to you.
::
::Paul
:::
::
:

Even tho drawing excess current and heating the frame, filament winding was 6.2vac and across HV was 325vac. Slowly removing paper/potting, looking for the obvious.

marv

:You could get lucky if you take the bells off and see if there is evidence of arcing with the connecting wires to the windings. I've seen this many a time. Unless you have shorted or open windings, very carefully check all connections, replace the leads if needed, tape everything up with multiple layers of electrical tape, paint the bells while they're off, and you just might save this one. If there is a lot of charring and the windings are loose, then it's not really safe to proceed. Just an aside, with all windings disconnected from the set, and powered up, you could see if it still overheats. There's no harm in powering up an otherwise transformer in good condition with no load - but the output voltages will measure higher than they will with a load.
:
:Just my 2 cents worth, but I would bet that a cycle trhough the dishwasher would exascerbate any corrosion that exists in the delicate windings of rf, if, and oscillator coils on an old set.
:
::The flickering pilot, erratic current drain and excess heat was there before washing and just got worse afterward. Wonder if pulling the rectifier allowed the unloaded HV winding to exceed the breakdown voltage of the original corrosion/crud to final hard short?
::
::marv
::
:::I have read about others washing radio chassis with water, and this has always struck me as fairly risky, compared to the relative benefits.
:::If I knew for a fact I could dry everything completely before any corrosion set in, then maybe.
:::I can not see washing anything with copper and paper winding in it.
:::For those that washed them and had good success, more power to you.
:::
:::Paul
::::
:::
::
:

Hi Marv,

I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!

Listening to that radio will always bring back "special" memories.

Gary

:Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:
:marv
:

Gary,
Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck

marv

:Hi Marv,
:
:I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:
:Listening to that radio will always bring back "special" memories.
:
:Gary
:
::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::
::marv
::
:

Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.

marv

:Gary,
:Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:
:marv
:
::Hi Marv,
::
::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::
::Listening to that radio will always bring back "special" memories.
::
::Gary
::
:::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::
:::marv
:::
::
:

Hi Marv,

The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.

Gary

:Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:
:marv
:
::Gary,
::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::
::marv
::
:::Hi Marv,
:::
:::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::
:::Listening to that radio will always bring back "special" memories.
:::
:::Gary
:::
::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::
::::marv
::::
:::
::
:

Marv

Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.

A shorted turn in any winding reflects back to the primary.

Best to replace all windings with new wire. Newer wire should have better insulation.

Norm

:Hi Marv,
:
:The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
:
:Gary
:
::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
::
::marv
::
:::Gary,
:::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:::
:::marv
:::
::::Hi Marv,
::::
::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::::
::::Listening to that radio will always bring back "special" memories.
::::
::::Gary
::::
:::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::::
:::::marv
:::::
::::
:::
::
:

I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.

marv

:Marv
:
: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
:
: A shorted turn in any winding reflects back to the primary.
:
: Best to replace all windings with new wire. Newer wire should have better insulation.
:
:Norm
:
::Hi Marv,
::
::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
::
::Gary
::
:::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:::
:::marv
:::
::::Gary,
::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::::
::::marv
::::
:::::Hi Marv,
:::::
:::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::::
:::::Listening to that radio will always bring back "special" memories.
:::::
:::::Gary
:::::
::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::::
::::::marv
::::::
:::::
::::
:::
::
:

Hi Marv

Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.

Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.

Norm

:I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
:
:marv
:
::Marv
::
:: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
::
:: A shorted turn in any winding reflects back to the primary.
::
:: Best to replace all windings with new wire. Newer wire should have better insulation.
::
::Norm
::
:::Hi Marv,
:::
:::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
:::
:::Gary
:::
::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
::::
::::marv
::::
:::::Gary,
:::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:::::
:::::marv
:::::
::::::Hi Marv,
::::::
::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::::::
::::::Listening to that radio will always bring back "special" memories.
::::::
::::::Gary
::::::
:::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::::::
:::::::marv
:::::::
::::::
:::::
::::
:::
::
:

Norm,
Norm,
I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers

marv

:Hi Marv
:
: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
:
: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
:
:Norm
:
::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
::
::marv
::
:::Marv
:::
::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
:::
::: A shorted turn in any winding reflects back to the primary.
:::
::: Best to replace all windings with new wire. Newer wire should have better insulation.
:::
:::Norm
:::
::::Hi Marv,
::::
::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
::::
::::Gary
::::
:::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:::::
:::::marv
:::::
::::::Gary,
::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::::::
::::::marv
::::::
:::::::Hi Marv,
:::::::
:::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::::::
:::::::Listening to that radio will always bring back "special" memories.
:::::::
:::::::Gary
:::::::
::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::::::
::::::::marv
::::::::
:::::::
::::::
:::::
::::
:::
::
:

Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
Bob

:Norm,
:Norm,
:I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
:
:marv
:
::Hi Marv
::
:: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
::
:: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
::
::Norm
::
:::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
:::
:::marv
:::
::::Marv
::::
:::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
::::
:::: A shorted turn in any winding reflects back to the primary.
::::
:::: Best to replace all windings with new wire. Newer wire should have better insulation.
::::
::::Norm
::::
:::::Hi Marv,
:::::
:::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
:::::
:::::Gary
:::::
::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
::::::
::::::marv
::::::
:::::::Gary,
:::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:::::::
:::::::marv
:::::::
::::::::Hi Marv,
::::::::
::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::::::::
::::::::Listening to that radio will always bring back "special" memories.
::::::::
::::::::Gary
::::::::
:::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::::::::
:::::::::marv
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.

marv

:Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
:Bob
:
::Norm,
::Norm,
::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
::
::marv
::
:::Hi Marv
:::
::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
:::
::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
:::
:::Norm
:::
::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
::::
::::marv
::::
:::::Marv
:::::
::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
:::::
::::: A shorted turn in any winding reflects back to the primary.
:::::
::::: Best to replace all windings with new wire. Newer wire should have better insulation.
:::::
:::::Norm
:::::
::::::Hi Marv,
::::::
::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
::::::
::::::Gary
::::::
:::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:::::::
:::::::marv
:::::::
::::::::Gary,
::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::::::::
::::::::marv
::::::::
:::::::::Hi Marv,
:::::::::
:::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::::::::
:::::::::Listening to that radio will always bring back "special" memories.
:::::::::
:::::::::Gary
:::::::::
::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::::::::
::::::::::marv
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.

marv

:Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
:
:marv
:
::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
::Bob
::
:::Norm,
:::Norm,
:::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
:::
:::marv
:::
::::Hi Marv
::::
:::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
::::
:::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
::::
::::Norm
::::
:::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
:::::
:::::marv
:::::
::::::Marv
::::::
:::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
::::::
:::::: A shorted turn in any winding reflects back to the primary.
::::::
:::::: Best to replace all windings with new wire. Newer wire should have better insulation.
::::::
::::::Norm
::::::
:::::::Hi Marv,
:::::::
:::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
:::::::
:::::::Gary
:::::::
::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
::::::::
::::::::marv
::::::::
:::::::::Gary,
:::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:::::::::
:::::::::marv
:::::::::
::::::::::Hi Marv,
::::::::::
::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::::::::::
::::::::::Listening to that radio will always bring back "special" memories.
::::::::::
::::::::::Gary
::::::::::
:::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::::::::::
:::::::::::marv
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.

:Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
:
:marv
:
::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
::
::marv
::
:::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
:::Bob
:::
::::Norm,
::::Norm,
::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
::::
::::marv
::::
:::::Hi Marv
:::::
::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
:::::
::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
:::::
:::::Norm
:::::
::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
::::::
::::::marv
::::::
:::::::Marv
:::::::
::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
:::::::
::::::: A shorted turn in any winding reflects back to the primary.
:::::::
::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
:::::::
:::::::Norm
:::::::
::::::::Hi Marv,
::::::::
::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
::::::::
::::::::Gary
::::::::
:::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:::::::::
:::::::::marv
:::::::::
::::::::::Gary,
::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::::::::::
::::::::::marv
::::::::::
:::::::::::Hi Marv,
:::::::::::
:::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::::::::::
:::::::::::Listening to that radio will always bring back "special" memories.
:::::::::::
:::::::::::Gary
:::::::::::
::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::::::::::
::::::::::::marv
::::::::::::
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

CF,
Used some small sticks of 1/2" dowel(finger turned)for storage. Perched the core on an axle in a small table vice on my bench. Took several hours for all 3 windings, but wanted to count turns, observing each for damage, shorting etc. The last winding (HV) next to the core had carbon trails at it's outside end. The only evidence of failure on any winding. Still trying to find small qty of #36 HV (1k ft); #28 Pri (250 ft) and #22 Fils.(50 ft) for rewind. Searched, but couldn't find a direct replacement for the xformer.

marv

:If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.
:
::Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
::
::marv
::
:::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
:::
:::marv
:::
::::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
::::Bob
::::
:::::Norm,
:::::Norm,
:::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
:::::
:::::marv
:::::
::::::Hi Marv
::::::
:::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
::::::
:::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
::::::
::::::Norm
::::::
:::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
:::::::
:::::::marv
:::::::
::::::::Marv
::::::::
:::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
::::::::
:::::::: A shorted turn in any winding reflects back to the primary.
::::::::
:::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
::::::::
::::::::Norm
::::::::
:::::::::Hi Marv,
:::::::::
:::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
:::::::::
:::::::::Gary
:::::::::
::::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
::::::::::
::::::::::marv
::::::::::
:::::::::::Gary,
:::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:::::::::::
:::::::::::marv
:::::::::::
::::::::::::Hi Marv,
::::::::::::
::::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::::::::::::
::::::::::::Listening to that radio will always bring back "special" memories.
::::::::::::
::::::::::::Gary
::::::::::::
:::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::::::::::::
:::::::::::::marv
:::::::::::::
::::::::::::
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

:CF,
:Used some small sticks of 1/2" dowel(finger turned)for storage. Perched the core on an axle in a small table vice on my bench. Took several hours for all 3 windings, but wanted to count turns, observing each for damage, shorting etc. The last winding (HV) next to the core had carbon trails at it's outside end. The only evidence of failure on any winding. Still trying to find small qty of #36 HV (1k ft); #28 Pri (250 ft) and #22 Fils.(50 ft) for rewind. Searched, but couldn't find a direct replacement for the xformer.
:
:marv
:
::If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.
::
:::Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
:::
:::marv
:::
::::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
::::
::::marv
::::
:::::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
:::::Bob
:::::
::::::Norm,
::::::Norm,
::::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
::::::
::::::marv
::::::
:::::::Hi Marv
:::::::
::::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
:::::::
::::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
:::::::
:::::::Norm
:::::::
::::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
::::::::
::::::::marv
::::::::
:::::::::Marv
:::::::::
::::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
:::::::::
::::::::: A shorted turn in any winding reflects back to the primary.
:::::::::
::::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
:::::::::
:::::::::Norm
:::::::::
::::::::::Hi Marv,
::::::::::
::::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
::::::::::
::::::::::Gary
::::::::::
:::::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:::::::::::
:::::::::::marv
:::::::::::
::::::::::::Gary,
::::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::::::::::::
::::::::::::marv
::::::::::::
:::::::::::::Hi Marv,
:::::::::::::
:::::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::::::::::::
:::::::::::::Listening to that radio will always bring back "special" memories.
:::::::::::::
:::::::::::::Gary
:::::::::::::
::::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::::::::::::
::::::::::::::marv
::::::::::::::
:::::::::::::
::::::::::::
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

Haven't tried this resource myself, but here it is:
http://www.oemwire.com/magnetwire.htm

:CF,
:Used some small sticks of 1/2" dowel(finger turned)for storage. Perched the core on an axle in a small table vice on my bench. Took several hours for all 3 windings, but wanted to count turns, observing each for damage, shorting etc. The last winding (HV) next to the core had carbon trails at it's outside end. The only evidence of failure on any winding. Still trying to find small qty of #36 HV (1k ft); #28 Pri (250 ft) and #22 Fils.(50 ft) for rewind. Searched, but couldn't find a direct replacement for the xformer.
:
:marv
:
::If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.
::
:::Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
:::
:::marv
:::
::::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
::::
::::marv
::::
:::::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
:::::Bob
:::::
::::::Norm,
::::::Norm,
::::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
::::::
::::::marv
::::::
:::::::Hi Marv
:::::::
::::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
:::::::
::::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
:::::::
:::::::Norm
:::::::
::::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
::::::::
::::::::marv
::::::::
:::::::::Marv
:::::::::
::::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
:::::::::
::::::::: A shorted turn in any winding reflects back to the primary.
:::::::::
::::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
:::::::::
:::::::::Norm
:::::::::
::::::::::Hi Marv,
::::::::::
::::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
::::::::::
::::::::::Gary
::::::::::
:::::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:::::::::::
:::::::::::marv
:::::::::::
::::::::::::Gary,
::::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::::::::::::
::::::::::::marv
::::::::::::
:::::::::::::Hi Marv,
:::::::::::::
:::::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::::::::::::
:::::::::::::Listening to that radio will always bring back "special" memories.
:::::::::::::
:::::::::::::Gary
:::::::::::::
::::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::::::::::::
::::::::::::::marv
::::::::::::::
:::::::::::::
::::::::::::
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

CF,
Hey!! Thanks!! Just the place I was looking for. Got everything I need in qty and prices I like.

marv

:Haven't tried this resource myself, but here it is:
:http://www.oemwire.com/magnetwire.htm
:
::CF,
::Used some small sticks of 1/2" dowel(finger turned)for storage. Perched the core on an axle in a small table vice on my bench. Took several hours for all 3 windings, but wanted to count turns, observing each for damage, shorting etc. The last winding (HV) next to the core had carbon trails at it's outside end. The only evidence of failure on any winding. Still trying to find small qty of #36 HV (1k ft); #28 Pri (250 ft) and #22 Fils.(50 ft) for rewind. Searched, but couldn't find a direct replacement for the xformer.
::
::marv
::
:::If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.
:::
::::Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
::::
::::marv
::::
:::::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
:::::
:::::marv
:::::
::::::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
::::::Bob
::::::
:::::::Norm,
:::::::Norm,
:::::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
:::::::
:::::::marv
:::::::
::::::::Hi Marv
::::::::
:::::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
::::::::
:::::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
::::::::
::::::::Norm
::::::::
:::::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
:::::::::
:::::::::marv
:::::::::
::::::::::Marv
::::::::::
:::::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
::::::::::
:::::::::: A shorted turn in any winding reflects back to the primary.
::::::::::
:::::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
::::::::::
::::::::::Norm
::::::::::
:::::::::::Hi Marv,
:::::::::::
:::::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
:::::::::::
:::::::::::Gary
:::::::::::
::::::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
::::::::::::
::::::::::::marv
::::::::::::
:::::::::::::Gary,
:::::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:::::::::::::
:::::::::::::marv
:::::::::::::
::::::::::::::Hi Marv,
::::::::::::::
::::::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::::::::::::::
::::::::::::::Listening to that radio will always bring back "special" memories.
::::::::::::::
::::::::::::::Gary
::::::::::::::
:::::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::::::::::::::
:::::::::::::::marv
:::::::::::::::
::::::::::::::
:::::::::::::
::::::::::::
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

OK, here's a question for anyone willing to comment. 2570 turns later (#36), was able to rewind the HV secondary with my manual winder, but DC resistance is approx 15% higher than a working unit. I'm sure my manual unit is not as accurate, nor winds as tight as a factory machine, but I duplicated the number of turns removed. So which is more important, number of turns or DC resistance, and will any added resistance cause heating or simply limit available current?

marv

:Haven't tried this resource myself, but here it is:
:http://www.oemwire.com/magnetwire.htm
:
::CF,
::Used some small sticks of 1/2" dowel(finger turned)for storage. Perched the core on an axle in a small table vice on my bench. Took several hours for all 3 windings, but wanted to count turns, observing each for damage, shorting etc. The last winding (HV) next to the core had carbon trails at it's outside end. The only evidence of failure on any winding. Still trying to find small qty of #36 HV (1k ft); #28 Pri (250 ft) and #22 Fils.(50 ft) for rewind. Searched, but couldn't find a direct replacement for the xformer.
::
::marv
::
:::If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.
:::
::::Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
::::
::::marv
::::
:::::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
:::::
:::::marv
:::::
::::::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
::::::Bob
::::::
:::::::Norm,
:::::::Norm,
:::::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
:::::::
:::::::marv
:::::::
::::::::Hi Marv
::::::::
:::::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
::::::::
:::::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
::::::::
::::::::Norm
::::::::
:::::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
:::::::::
:::::::::marv
:::::::::
::::::::::Marv
::::::::::
:::::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
::::::::::
:::::::::: A shorted turn in any winding reflects back to the primary.
::::::::::
:::::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
::::::::::
::::::::::Norm
::::::::::
:::::::::::Hi Marv,
:::::::::::
:::::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
:::::::::::
:::::::::::Gary
:::::::::::
::::::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
::::::::::::
::::::::::::marv
::::::::::::
:::::::::::::Gary,
:::::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:::::::::::::
:::::::::::::marv
:::::::::::::
::::::::::::::Hi Marv,
::::::::::::::
::::::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::::::::::::::
::::::::::::::Listening to that radio will always bring back "special" memories.
::::::::::::::
::::::::::::::Gary
::::::::::::::
:::::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::::::::::::::
:::::::::::::::marv
:::::::::::::::
::::::::::::::
:::::::::::::
::::::::::::
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

Marv,

If you are sure about the number of turns then consider the following:

36 AWG wire has 424 Ohms / 1000 feet
35 AWG wire has 338 Ohms / 1000 feet

As you can see 35AWG is 21% lower that 36. This is significant considering only one AWG difference.

Is it possible that the original HV winding was wound with 35 WG wire?

Just a thought.

Gary

:OK, here's a question for anyone willing to comment. 2570 turns later (#36), was able to rewind the HV secondary with my manual winder, but DC resistance is approx 15% higher than a working unit. I'm sure my manual unit is not as accurate, nor winds as tight as a factory machine, but I duplicated the number of turns removed. So which is more important, number of turns or DC resistance, and will any added resistance cause heating or simply limit available current?
:
:marv
:
::Haven't tried this resource myself, but here it is:
::http://www.oemwire.com/magnetwire.htm
::
:::CF,
:::Used some small sticks of 1/2" dowel(finger turned)for storage. Perched the core on an axle in a small table vice on my bench. Took several hours for all 3 windings, but wanted to count turns, observing each for damage, shorting etc. The last winding (HV) next to the core had carbon trails at it's outside end. The only evidence of failure on any winding. Still trying to find small qty of #36 HV (1k ft); #28 Pri (250 ft) and #22 Fils.(50 ft) for rewind. Searched, but couldn't find a direct replacement for the xformer.
:::
:::marv
:::
::::If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.
::::
:::::Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
:::::
:::::marv
:::::
::::::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
::::::
::::::marv
::::::
:::::::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
:::::::Bob
:::::::
::::::::Norm,
::::::::Norm,
::::::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
::::::::
::::::::marv
::::::::
:::::::::Hi Marv
:::::::::
::::::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
:::::::::
::::::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
:::::::::
:::::::::Norm
:::::::::
::::::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
::::::::::
::::::::::marv
::::::::::
:::::::::::Marv
:::::::::::
::::::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
:::::::::::
::::::::::: A shorted turn in any winding reflects back to the primary.
:::::::::::
::::::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
:::::::::::
:::::::::::Norm
:::::::::::
::::::::::::Hi Marv,
::::::::::::
::::::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
::::::::::::
::::::::::::Gary
::::::::::::
:::::::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:::::::::::::
:::::::::::::marv
:::::::::::::
::::::::::::::Gary,
::::::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::::::::::::::
::::::::::::::marv
::::::::::::::
:::::::::::::::Hi Marv,
:::::::::::::::
:::::::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::::::::::::::
:::::::::::::::Listening to that radio will always bring back "special" memories.
:::::::::::::::
:::::::::::::::Gary
:::::::::::::::
::::::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::::::::::::::
::::::::::::::::marv
::::::::::::::::
:::::::::::::::
::::::::::::::
:::::::::::::
::::::::::::
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

Gary,
After cleaning the old wire, measured it several times, over a few inches length with Mitutoyo digital micrometer, so measurement is probably more accurate than turns count coming off the core or going back on. Even brand new wire varies a few 1000ths from specs. If there was excess crud on the wire, then actual AWG would have been smaller, with higher DC resistance. I used some cloth tape from drug store between layers, which is either cotton, fiberglas or some poly mat'l. It is actually thinner than orig resin coated brown paper. Used thinned shellac as a coating/glue, but don't know what it's HV properties are. My winding rig needs a little fine tuning especially for the next 513 turns of #28 for the primary.

marv

:Marv,
:
:If you are sure about the number of turns then consider the following:
:
:36 AWG wire has 424 Ohms / 1000 feet
:35 AWG wire has 338 Ohms / 1000 feet
:
:As you can see 35AWG is 21% lower that 36. This is significant considering only one AWG difference.
:
:Is it possible that the original HV winding was wound with 35 WG wire?
:
:Just a thought.
:
:Gary
:
:
:
::OK, here's a question for anyone willing to comment. 2570 turns later (#36), was able to rewind the HV secondary with my manual winder, but DC resistance is approx 15% higher than a working unit. I'm sure my manual unit is not as accurate, nor winds as tight as a factory machine, but I duplicated the number of turns removed. So which is more important, number of turns or DC resistance, and will any added resistance cause heating or simply limit available current?
::
::marv
::
:::Haven't tried this resource myself, but here it is:
:::http://www.oemwire.com/magnetwire.htm
:::
::::CF,
::::Used some small sticks of 1/2" dowel(finger turned)for storage. Perched the core on an axle in a small table vice on my bench. Took several hours for all 3 windings, but wanted to count turns, observing each for damage, shorting etc. The last winding (HV) next to the core had carbon trails at it's outside end. The only evidence of failure on any winding. Still trying to find small qty of #36 HV (1k ft); #28 Pri (250 ft) and #22 Fils.(50 ft) for rewind. Searched, but couldn't find a direct replacement for the xformer.
::::
::::marv
::::
:::::If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.
:::::
::::::Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
::::::
::::::marv
::::::
:::::::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
:::::::
:::::::marv
:::::::
::::::::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
::::::::Bob
::::::::
:::::::::Norm,
:::::::::Norm,
:::::::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
:::::::::
:::::::::marv
:::::::::
::::::::::Hi Marv
::::::::::
:::::::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
::::::::::
:::::::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
::::::::::
::::::::::Norm
::::::::::
:::::::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
:::::::::::
:::::::::::marv
:::::::::::
::::::::::::Marv
::::::::::::
:::::::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
::::::::::::
:::::::::::: A shorted turn in any winding reflects back to the primary.
::::::::::::
:::::::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
::::::::::::
::::::::::::Norm
::::::::::::
:::::::::::::Hi Marv,
:::::::::::::
:::::::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
:::::::::::::
:::::::::::::Gary
:::::::::::::
::::::::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
::::::::::::::
::::::::::::::marv
::::::::::::::
:::::::::::::::Gary,
:::::::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
:::::::::::::::
:::::::::::::::marv
:::::::::::::::
::::::::::::::::Hi Marv,
::::::::::::::::
::::::::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
::::::::::::::::
::::::::::::::::Listening to that radio will always bring back "special" memories.
::::::::::::::::
::::::::::::::::Gary
::::::::::::::::
:::::::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
:::::::::::::::::
:::::::::::::::::marv
:::::::::::::::::
::::::::::::::::
:::::::::::::::
::::::::::::::
:::::::::::::
::::::::::::
:::::::::::
::::::::::
:::::::::
::::::::
:::::::
::::::
:::::
::::
:::
::
:

OK, the build-up was too big when I got out to the final LV winding. Wouldn't fit into the core between the arms of the "E" Taking it all off again. Will reduce the number of layers by adding turns to each one, and maybe that'll reduce the overall diameter. Switching to a thinner tape between layers too. Assuming total number of turns determines final volts, regardless of layer count.

marv

:OK, here's a question for anyone willing to comment. 2570 turns later (#36), was able to rewind the HV secondary with my manual winder, but DC resistance is approx 15% higher than a working unit. I'm sure my manual unit is not as accurate, nor winds as tight as a factory machine, but I duplicated the number of turns removed. So which is more important, number of turns or DC resistance, and will any added resistance cause heating or simply limit available current?
:
:marv
:
::Haven't tried this resource myself, but here it is:
::http://www.oemwire.com/magnetwire.htm
::
:::CF,
:::Used some small sticks of 1/2" dowel(finger turned)for storage. Perched the core on an axle in a small table vice on my bench. Took several hours for all 3 windings, but wanted to count turns, observing each for damage, shorting etc. The last winding (HV) next to the core had carbon trails at it's outside end. The only evidence of failure on any winding. Still trying to find small qty of #36 HV (1k ft); #28 Pri (250 ft) and #22 Fils.(50 ft) for rewind. Searched, but couldn't find a direct replacement for the xformer.
:::
:::marv
:::
::::If it's just a few turns, just splice the good ends together and rewind it. A drop of varnish should do it. I once unwound a field call in an old speaker that had at least 5 splices. I guess they were using ends of reels that day. BTW how do you store the unwound wire when you are undertaking this chore? Gotta be something more sophisticated than my fishing reel method.
::::
:::::Well 16 layers and 2570 turns later on the HV winding, found a lot of missing enamel, but only 1 small carbon trace indicating a short/arcing/failure. Now where to find needed quantities of enamel wire to put it all back on, and duplicate that onion skin paper insulator between layers. Think I'll try double sticky tape and regular wax paper with spray lacquer. Have some real thin woven glass medical tape, which might be helpful too.
:::::
:::::marv
:::::
::::::Forgive my ignorance, but this little foray into the world of xformers has raised a couple ?? The primary is wound layer after layer in 1 direction, whereas the 2 layers of LV secondary was wound opposing, as I assume the HV secondary will be. Then start of first (inner) is tied to end of second (outer), and end of the first tied to start of second. The HV start and end are tied together to form the CT. Now we need Mr. er, Dr. EDD, our resident physicist to enlighten us. I assume this is to prevent secondary fields from the induced winding from further inducing currents into the other layer(s). And if they were not counter-wound, would fields from the induced winding continue to build to self destruction or counteract the primary field, and halt the xformer action completely. Would this action be akin to pulse transformer forming networks of yesteryear tube ckts. Thanks all.
::::::
::::::marv
::::::
:::::::Think of any shorted turns, on any winding as a seperate winding that is shorted. That is how the primary sees it. yes, a single turn that is shorted will make very little difference in the output voltage of that winding, but it will cause high current in that shorted winding, the power for it coming from the primary. Hope this helps.
:::::::Bob
:::::::
::::::::Norm,
::::::::Norm,
::::::::I follow, a dead short, and obviously loaded heavily, but isn't it unlikely that the first turn is connected to the last turn on my HV secondary, otherwise I wouldn't see 237 ohms series resistance across them, and even shorting several parallel turns within one layer would only cause the # of turns to decrease lowering the voltage. From a practical standpoint (excluding Murphy), shorting turn(s) on beginning layer(s) to a turn on subsequent layer(s), with higher voltage potential between the two points will cause current flow, excess loading reflected to primary and heat. Maybe I need to study more about volts/turn and magnetic structure of power transformers
::::::::
::::::::marv
::::::::
:::::::::Hi Marv
:::::::::
::::::::: Any shorted turns on a winding reflects back to the primary. A shorted turn on a filament winding can make the primary overheat.
:::::::::
::::::::: Even one shorted turn in a transformer causes heating. Here is something you can try. Wind one turn around a transformer core and connect the ends together. Either the wire will burn out or the transformer will start heating.
:::::::::
:::::::::Norm
:::::::::
::::::::::I'm not a transformer expert, but seems to me that shorted turns in an unloaded (no rectifier) HV secondary would only LOWER it's voltage wo/ loading the primary. Completely removed, the LV 6.3vac winding was running low (6vac), the HV was 325vac, and frame was hot, which pointed to shorted turns in the primary. This morn, confirmed the same xformer (pn) is in the FM tuner counterpart. Unloaded (no rectifier)HV secondary runs 517vac vs 325 on bad part. Filaments still powered, primary current was 227ma @120vac line. Initially, (after dishwasher)the AM unit played fine for several hours, but when disconnecting to set up FM unit, the chassis was hot near the xformer. After several hours the FM unit was barely warm, then knew I had a problem. Murphy lives. The last winding, most difficult to repair, with the finest wire must be the culprit.
::::::::::
::::::::::marv
::::::::::
:::::::::::Marv
:::::::::::
::::::::::: Going by DC resistance won't detect a few shorted turns. Resistance will only change an ohm or two but any shorted turn cause a transformer to overheat.
:::::::::::
::::::::::: A shorted turn in any winding reflects back to the primary.
:::::::::::
::::::::::: Best to replace all windings with new wire. Newer wire should have better insulation.
:::::::::::
:::::::::::Norm
:::::::::::
::::::::::::Hi Marv,
::::::::::::
::::::::::::The HV winding may be fine until put under the stress of HV. What is the expected HV output of your xfrm? The resistance meausrement sounds about right. Do you have an AC Amp meter? This may help detect if the coils are shorting when you increase the voltage. When I did the HV winding on mine the total resistance was 325ohms (158 and 167). Ended up being 736Vct unloaded,(around 368V per side). The HV winding was 16 layers of 170 turns of #32 wire. One thing I did was apply capton tape between each layer. This helped secure each layer and provided insulation between layers. My thinking was for the tape to be a substitue for the waxed paper. Unfortunately, it did make the overall dia of the windings too big for the E core laminations, which I had to file down to fit.
::::::::::::
::::::::::::Gary
::::::::::::
:::::::::::::Seven layers and 513 turns later, no evidence of primary shorting. A few areas of missing enamel, but no smoking gun. May have done some of that enamel removal peeling off the wax paper with a knife. Still measures the same 17.4 ohms off the core. The denatured alcohol helped soften the wax paper and tape, so unwinding was easier. Dread to think it's the HV (inner)winding of about 25 layers of 150 turns #36. It measures 237 ohms dc resistance. Guess I could try low, mediium, high line voltage across it to see if it fries like before, but don't know how long #36 would last at approx 0.5A with full line voltage. Fusing current for #36 is rated at 3.6A according to my Radio Engineer's Handbook.
:::::::::::::
:::::::::::::marv
:::::::::::::
::::::::::::::Gary,
::::::::::::::Yea, that's where I am right now. Got the laminations separated and removed. Apparently not thermo-setting varnish I've seen before. Used lacquer thinner for clean-up. Outside winding (LV 6.3vac) just 2 layers, 77 turns #22 total counter-wound. Down to the primary (problem area) #27, trying to peel off thin wax paper. Think I'll try denatured alcohol to soften wax or whatever, then unwind 'till I find short. No evidence of burns/scorching, so it'll be a chore. Inner winding is HV #36, but won't need to disturb it. No shorts found between windings. I have Heath FM tuner counter part, with what appears to be identical pwr supplie, but numbers stamped on xformer frames are different. Wish me luck
::::::::::::::
::::::::::::::marv
::::::::::::::
:::::::::::::::Hi Marv,
:::::::::::::::
:::::::::::::::I feel your pain. Did a similar washing on a Philco Model 20 with the power xfmr installed (OOPS). After drying in the oven for hours the pwr xfmr still fizzled and got hot. The HV winding had overheated, arched etc. I am not sure if it was bad to begin with. Anyway, I ended up REWINDING the HV secondary! What a job that was. 2720 turns of #32 wire later, much much later, I had a working xfmr agian. NEVER AGAIN! Yeah right!
:::::::::::::::
:::::::::::::::Listening to that radio will always bring back "special" memories.
:::::::::::::::
:::::::::::::::Gary
:::::::::::::::
::::::::::::::::Did the Peter B. trick in the dishwasher tubes and all. Glued in plastic dial was loose, so put it in the silverware basket, and ended up on the heating element after wash cycle. Damn, I hate the smell of melting acrylic. Other problem is (I think) water left within the power xformer winding. With rectifier out, pilot lite flickers at random, xformer gets HOT with slight frying sound from that area. AC current drain nom. 60ma, but jumps around with the flicker to as much as 95ma. Should I remove xformer for a 2 hr drying cycle in my oven?
::::::::::::::::
::::::::::::::::marv
::::::::::::::::
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: