Can I just get any 455 2nd IF transformer rated for a tube amp? and put it in? I will put the 2 x 100pF and 47K outside (or inside) the can if I need to.
Any thoughts or tips? Any type of caps better than others? Does the ohm rating matter? I think the current one is about 20 ohms per side...
THX
:
:Can I just get any 455 2nd IF transformer rated for a tube amp? and put it in? I will put the 2 x 100pF and 47K outside (or inside) the can if I need to.
:
:Any thoughts or tips? Any type of caps better than others? Does the ohm rating matter? I think the current one is about 20 ohms per side...
:
:THX
:
Hi Bubba,
It looks like a very routine output transformer. You will need to re-create that internal circuitry outside the IF.
A good phical fit will likely be the biggest challenge.
A radio with a 12SK7 IF and 12SQ7 detector could be a good donor chassis.
All the Best,
Bill Grimm
:Sometimes it’s possible to replace just the coils from the donor IF. Use the original ceramic trimmers that have the two capacitors and resistor under it. Put it back inside the original can. Normally it’s the length of the coil form that is the factor.
:
Or would i be better off replacing the entire can?
:
:
:
:
::Sometimes it’s possible to replace just the coils from the donor IF. Use the original ceramic trimmers that have the two capacitors and resistor under it. Put it back inside the original can. Normally it’s the length of the coil form that is the factor.
::
:
:
Glad you got the tubes figured out. The 7H7 tube can be used in a radio with parallel filaments. It takes twice the current (0.3 amp)at 6.3 volts to light it whereas the 7C7 & 7B7 take only 0.150 amp at 6.3 volts. The other tubes in your set are also 0.150 amp tubes. The 7H7 most likely was not lighting up at all or very little.
Clifton
:After going through this mess with my Philco open IF tap then unwinding it and basically IMO wrecking it. I have decided to replace the 2nd IF transformer or output IF with another.
:
:Can I just get any 455 2nd IF transformer rated for a tube amp? and put it in? I will put the 2 x 100pF and 47K outside (or inside) the can if I need to.
:
:Any thoughts or tips? Any type of caps better than others? Does the ohm rating matter? I think the current one is about 20 ohms per side...
:
:THX
:
Can I use jumpers (short alligator clip) to swap the iF transformers out one after another or is lead length a sensitive issue with the RF coils?
:Bubba,
:
:Glad you got the tubes figured out. The 7H7 tube can be used in a radio with parallel filaments. It takes twice the current (0.3 amp)at 6.3 volts to light it whereas the 7C7 & 7B7 take only 0.150 amp at 6.3 volts. The other tubes in your set are also 0.150 amp tubes. The 7H7 most likely was not lighting up at all or very little.
:
:Clifton
:
:
::After going through this mess with my Philco open IF tap then unwinding it and basically IMO wrecking it. I have decided to replace the 2nd IF transformer or output IF with another.
::
::Can I just get any 455 2nd IF transformer rated for a tube amp? and put it in? I will put the 2 x 100pF and 47K outside (or inside) the can if I need to.
::
::Any thoughts or tips? Any type of caps better than others? Does the ohm rating matter? I think the current one is about 20 ohms per side...
::
::THX
::
:
:
I would keep the leads as short as possible to prevent uncontrollable oscillations. I believe your radio uses 455Kc If transformers. Not sure what you have. IF transformers were made in different frequencies such as 455Kc, 262.5Kc, 10.7Mc, etc. Also make sure you have the wires soldered to the correct places. If wired wrong may not have plate voltage on the last IF tube. Also the transformer will have to have the tuning touched up.
Clifton
:I went and got about 7 IF transformers about the same size and ohm reading. I cannot seem to get any of them to work really well. I did build that RC network with the 100pF Caps. I am pretty sure I wired it right.
:
:Can I use jumpers (short alligator clip) to swap the iF transformers out one after another or is lead length a sensitive issue with the RF coils?
:
:
:
:
:
:
:
:
::Bubba,
::
::Glad you got the tubes figured out. The 7H7 tube can be used in a radio with parallel filaments. It takes twice the current (0.3 amp)at 6.3 volts to light it whereas the 7C7 & 7B7 take only 0.150 amp at 6.3 volts. The other tubes in your set are also 0.150 amp tubes. The 7H7 most likely was not lighting up at all or very little.
::
::Clifton
::
::
:::After going through this mess with my Philco open IF tap then unwinding it and basically IMO wrecking it. I have decided to replace the 2nd IF transformer or output IF with another.
:::
:::Can I just get any 455 2nd IF transformer rated for a tube amp? and put it in? I will put the 2 x 100pF and 47K outside (or inside) the can if I need to.
:::
:::Any thoughts or tips? Any type of caps better than others? Does the ohm rating matter? I think the current one is about 20 ohms per side...
:::
:::THX
:::
::
::
:
:
Anyone got a spare one of these?
Does it make a different that it was an ACDC radio? I used 100pF for theR/C network not 110 pF but that should not matter should it?
:Bubba,
:
:I would keep the leads as short as possible to prevent uncontrollable oscillations. I believe your radio uses 455Kc If transformers. Not sure what you have. IF transformers were made in different frequencies such as 455Kc, 262.5Kc, 10.7Mc, etc. Also make sure you have the wires soldered to the correct places. If wired wrong may not have plate voltage on the last IF tube. Also the transformer will have to have the tuning touched up.
:
:Clifton
:
:
::I went and got about 7 IF transformers about the same size and ohm reading. I cannot seem to get any of them to work really well. I did build that RC network with the 100pF Caps. I am pretty sure I wired it right.
::
::Can I use jumpers (short alligator clip) to swap the iF transformers out one after another or is lead length a sensitive issue with the RF coils?
::
::
::
::
::
::
::
::
:::Bubba,
:::
:::Glad you got the tubes figured out. The 7H7 tube can be used in a radio with parallel filaments. It takes twice the current (0.3 amp)at 6.3 volts to light it whereas the 7C7 & 7B7 take only 0.150 amp at 6.3 volts. The other tubes in your set are also 0.150 amp tubes. The 7H7 most likely was not lighting up at all or very little.
:::
:::Clifton
:::
:::
::::After going through this mess with my Philco open IF tap then unwinding it and basically IMO wrecking it. I have decided to replace the 2nd IF transformer or output IF with another.
::::
::::Can I just get any 455 2nd IF transformer rated for a tube amp? and put it in? I will put the 2 x 100pF and 47K outside (or inside) the can if I need to.
::::
::::Any thoughts or tips? Any type of caps better than others? Does the ohm rating matter? I think the current one is about 20 ohms per side...
::::
::::THX
::::
:::
:::
::
::
:
:
If the transformers you have are 455Kc transformers, they should work. I have even replaced the large 455 ones with the newer miniature types before successfully. I mounted the mini to the chassis and put the old IF can over it after tuning. I wonder if something else has gone kaput?
Clifton
:Is there somthing different about Philco IF output transformers compared to the average? I have tried about 4 or 5 that I got from the radio museum and none of them work.. I can get close but no stations. just the spot where the stations would be chirps and alot of oscillation when I go to adjust for max output.. I had radio with the open one one I rewound but after trying all of these,, nothing.
:
:Anyone got a spare one of these?
:
:Does it make a different that it was an ACDC radio? I used 100pF for theR/C network not 110 pF but that should not matter should it?
:
:
:
:
:
:
::Bubba,
::
::I would keep the leads as short as possible to prevent uncontrollable oscillations. I believe your radio uses 455Kc If transformers. Not sure what you have. IF transformers were made in different frequencies such as 455Kc, 262.5Kc, 10.7Mc, etc. Also make sure you have the wires soldered to the correct places. If wired wrong may not have plate voltage on the last IF tube. Also the transformer will have to have the tuning touched up.
::
::Clifton
::
::
:::I went and got about 7 IF transformers about the same size and ohm reading. I cannot seem to get any of them to work really well. I did build that RC network with the 100pF Caps. I am pretty sure I wired it right.
:::
:::Can I use jumpers (short alligator clip) to swap the iF transformers out one after another or is lead length a sensitive issue with the RF coils?
:::
:::
:::
:::
:::
:::
:::
:::
::::Bubba,
::::
::::Glad you got the tubes figured out. The 7H7 tube can be used in a radio with parallel filaments. It takes twice the current (0.3 amp)at 6.3 volts to light it whereas the 7C7 & 7B7 take only 0.150 amp at 6.3 volts. The other tubes in your set are also 0.150 amp tubes. The 7H7 most likely was not lighting up at all or very little.
::::
::::Clifton
::::
::::
:::::After going through this mess with my Philco open IF tap then unwinding it and basically IMO wrecking it. I have decided to replace the 2nd IF transformer or output IF with another.
:::::
:::::Can I just get any 455 2nd IF transformer rated for a tube amp? and put it in? I will put the 2 x 100pF and 47K outside (or inside) the can if I need to.
:::::
:::::Any thoughts or tips? Any type of caps better than others? Does the ohm rating matter? I think the current one is about 20 ohms per side...
:::::
:::::THX
:::::
::::
::::
:::
:::
::
::
:
:
I am in agreement with Clifton. You have something other than the IF as a problem.
Time to look beyond the can.
Best Regards,
Bill Grimm
:Hi Bubba,
: I am in agreement with Clifton. You have something other than the IF as a problem.
: Time to look beyond the can.
:
:Best Regards,
:
:Bill Grimm
:
Make sure you have the unit wired in correctly. After hooking the transformer up, make sure you have plate voltage on the last IF tube. Under references and color code gives the color for the old style IF transformer leads. If your transformers have solder tabs instead of leads, use an ohmmeter to verify the primary and secondary leads otherwise one may wire a primary lead and a secondary lead to the plate and B+ of the IF tube circuit and the same for the second detector diode and volume control. That wouldn't work.
Clifton
:Damn,, I think you guys may be right. But I had radio right before I unhooked the original can and started trying these replacements. Could anything else go wrong? I will test the tubes again and take voltages after I put a replacement 455 Can in the right spot not using alligator clips.. Thanx for the input..
:
:
:
:
::Hi Bubba,
:: I am in agreement with Clifton. You have something other than the IF as a problem.
:: Time to look beyond the can.
::
::Best Regards,
::
::Bill Grimm
::
:
:
:Bubba,
:
:Make sure you have the unit wired in correctly. After hooking the transformer up, make sure you have plate voltage on the last IF tube. Under references and color code gives the color for the old style IF transformer leads. If your transformers have solder tabs instead of leads, use an ohmmeter to verify the primary and secondary leads otherwise one may wire a primary lead and a secondary lead to the plate and B+ of the IF tube circuit and the same for the second detector diode and volume control. That wouldn't work.
:
:Clifton
:
:
::Damn,, I think you guys may be right. But I had radio right before I unhooked the original can and started trying these replacements. Could anything else go wrong? I will test the tubes again and take voltages after I put a replacement 455 Can in the right spot not using alligator clips.. Thanx for the input..
::
::
::
::
:::Hi Bubba,
::: I am in agreement with Clifton. You have something other than the IF as a problem.
::: Time to look beyond the can.
:::
:::Best Regards,
:::
:::Bill Grimm
:::
::
::
:
:
Lets now proceed in the following mannner: Now . . . . Standing by for your test evaluation . . . . |
:
:I will confirm but, I can tune it up and as I turn the vernier dial I can hear where the stations should be because it makes a noise where each station would be but does not produce audio just a quick chirp. I wonder if the detector tube could be now bad?
:
:
::Bubba,
::
::Make sure you have the unit wired in correctly. After hooking the transformer up, make sure you have plate voltage on the last IF tube. Under references and color code gives the color for the old style IF transformer leads. If your transformers have solder tabs instead of leads, use an ohmmeter to verify the primary and secondary leads otherwise one may wire a primary lead and a secondary lead to the plate and B+ of the IF tube circuit and the same for the second detector diode and volume control. That wouldn't work.
::
::Clifton
::
::
:::Damn,, I think you guys may be right. But I had radio right before I unhooked the original can and started trying these replacements. Could anything else go wrong? I will test the tubes again and take voltages after I put a replacement 455 Can in the right spot not using alligator clips.. Thanx for the input..
:::
:::
:::
::::Hi Bubba,
:::: I am in agreement with Clifton. You have something other than the IF as a problem.
:::: Time to look beyond the can.
::::
::::Best Regards,
::::
::::Bill Grimm
::::
:::
:::
::
::
:
:
(between here>>>>>>>>>>>>>>>>>)
I had full working radio with original, "half hand wound" 2nd IF and I had just replaced 7H7 and other 7B7 with swap outs for the museum... The Philco then ran for about 1 hour working with full operation.... Then all I was going to do was replace the IF transformer with a proper one,, and when I did, I could not get Radio Audio back again. One point of interest is where the holes are in the metal chassis that let the wires through to the circuitry, under the 2nd IF can when I pulled the wires out (I noticed that there were 3 holes in the chassis) 1 wire had it's own hole and 2 (I think) were shared by 2 wires.. I should have taken a photo but now I cannot remember which colors were where and I wonder if this having the wrong wires too close together may be stopping the IF replacments from working and also oscillating. I would guess that I need to keep the Plate and B- away from the others?
I will look at photos I did take to see if I can figure out what holes had what color wires.. Then I will wire in Txformer and do above..
THX Ed..
(And here>>>>>>>>>>>>>>>>>>>>>)
Also, you were having problems in the sub in of a multitude of other "test" 455 IF transformers for your sets 2nd IF transformer.
:
:
:
:
:
:
:
:
:
:
:
:
:
:Sir Bubba. . . . .
:
:
:Know whut I "thanks" . . .
:
:
:That basically . . . you had your Philco unit that was working well enough to have an audio section operational enough, and to be able to let it "sound off" with the the amplified stray 60/120 cycle signal that was injected into the volume controls high side.
:
:
:Your further exploration then revealed a long time dead, crystal cartridge being in the phonos tone arm.
:
:
:That then brings you up to the testing of the units non existant radio performance.
:
:
:Now if the unit had a missing tube(s) or the improper ones installed . . . either by you or by someone in the past . . . that tends to explain the fallacy of the RF aspect of the radio not operating.
:
:
:I am referring specifically to my very earlier mentioned caveat of :
:
:
:
:Somewhere back in your threads branch offs there was mention of a 7H7 sitting in the RF slot . . . since this set is using 150 ma series string filamental wiring . . .that current starved 7H7 tube would not come up to high enough emission temperature . . so be sure that either a 7C7 or 7B7 ends up in that RF / IF tube slot. . . .which I do think that you confirmed later on.
:
:
:Now we are up to the problem of getting that IF stage operational:
:
:
:
:Lets now proceed in the following mannner:
:
:
:You had success in monitoring the output of the RF and Mixer stages by the capacitive coupling of the mixer plates signal to the transistor "monitor " receiver tuned to the second harmonic of 455Khz (910 Khz).
:
:
:You professed of satisfactory reception of a CBC station ( but not of its AM xmit frequency ? . . . those CBC's affiliates are a l l l l l over Canada. )
:
:
:Also, you were having problems in the sub in of a multitude of other "test" 455 IF transformers for your sets 2nd IF transformer.
:
:
:I have done this many times and usually just lay the transformer close to the bottom of the chassis side of the IF section and use either the transformers leads or solder tack on some test jumper leads to the transformers.
:terminals of newer or smaller units .
:
:
:Now you have already seen that the "radiating" terminal of an IF transformer is its plate connected terminal, so THAT lead, is the one that you want to keep any excess wire lead length to a MINIMUM on.
:
:
:Also run a short leaded clip lead from the case of the subbed in IF transformer to chassis ground.
:
:
:Now move back to the situation of hooking up the monitoring transistor radio to the plate of the Mixer tube by capacitive coupling . . . and getting that CBC station coming in again . . . as well as it was received previously.
:
:
:Now we need . . . minimally . . . to only have the plate winding and B+ supply connection to the subbed in IF transformer being wired in.
:
:
:You THEN take the previously connected jumper from the plate of the Mixer, and move it to the plate connection of the IF amplifier tube.
:
:
:I am now expecting a STROOONNNNG signal to be coming from that transistor "monitor" . . . as was being compared to the previously demonstrated "naked" mixer output signal.
:
:
:If successful . . . run a test on the rest of all of your IF transformers . . . . pick the best one . . . if such is apparent ?
:
:
:
:Now . . . . Standing by for your test evaluation . . . .
:
:
:
:
:
:
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:
:
::I will confirm but, I can tune it up and as I turn the vernier dial I can hear where the stations should be because it makes a noise where each station would be but does not produce audio just a quick chirp. I wonder if the detector tube could be now bad?
::
::
:
:
::
:::Bubba,
:::
:::Make sure you have the unit wired in correctly. After hooking the transformer up, make sure you have plate voltage on the last IF tube. Under references and color code gives the color for the old style IF transformer leads. If your transformers have solder tabs instead of leads, use an ohmmeter to verify the primary and secondary leads otherwise one may wire a primary lead and a secondary lead to the plate and B+ of the IF tube circuit and the same for the second detector diode and volume control. That wouldn't work.
:::
:::Clifton
:::
:::
:
:
:
:
::::Damn,, I think you guys may be right. But I had radio right before I unhooked the original can and started trying these replacements. Could anything else go wrong? I will test the tubes again and take voltages after I put a replacement 455 Can in the right spot not using alligator clips.. Thanx for the input..
::::
:
::::
::::
:::::Hi Bubba,
::::: I am in agreement with Clifton. You have something other than the IF as a problem.
::::: Time to look beyond the can.
:::::
:::::Best Regards,
:::::
:::::Bill Grimm
:::::
::::
::::
:::
:::
::
::
:
:
Assuming the transformer lead colors are blue (or white) for the last IF tube plate, red for the B+, green for the diode plate in the second detector and brown or black for the diode return. I would keep the IF plate and B+ leads away from the diode and return leads as far as possible. You might get some idea by looking at the wires coming out of the first IF transformer and how they are routed thru the chassis.
Clifton
:"You professed of satisfactory reception of a CBC station ( but not of its AM xmit frequency ? . . . those CBC's affiliates are a l l l l l over Canada.)"
:
:
:(between here>>>>>>>>>>>>>>>>>)
:
:I had full working radio with original, "half hand wound" 2nd IF and I had just replaced 7H7 and other 7B7 with swap outs for the museum... The Philco then ran for about 1 hour working with full operation.... Then all I was going to do was replace the IF transformer with a proper one,, and when I did, I could not get Radio Audio back again. One point of interest is where the holes are in the metal chassis that let the wires through to the circuitry, under the 2nd IF can when I pulled the wires out (I noticed that there were 3 holes in the chassis) 1 wire had it's own hole and 2 (I think) were shared by 2 wires.. I should have taken a photo but now I cannot remember which colors were where and I wonder if this having the wrong wires too close together may be stopping the IF replacments from working and also oscillating. I would guess that I need to keep the Plate and B- away from the others?
:
:I will look at photos I did take to see if I can figure out what holes had what color wires.. Then I will wire in Txformer and do above..
:
:THX Ed..
:
:
: (And here>>>>>>>>>>>>>>>>>>>>>)
:
:Also, you were having problems in the sub in of a multitude of other "test" 455 IF transformers for your sets 2nd IF transformer.
:
:
:
:
:
:
:
::
::
::
::
::
::
::
::
::
::
::
::
::
::Sir Bubba. . . . .
::
::
::Know whut I "thanks" . . .
::
::
::That basically . . . you had your Philco unit that was working well enough to have an audio section operational enough, and to be able to let it "sound off" with the the amplified stray 60/120 cycle signal that was injected into the volume controls high side.
::
::
::Your further exploration then revealed a long time dead, crystal cartridge being in the phonos tone arm.
::
::
::That then brings you up to the testing of the units non existant radio performance.
::
::
::Now if the unit had a missing tube(s) or the improper ones installed . . . either by you or by someone in the past . . . that tends to explain the fallacy of the RF aspect of the radio not operating.
::
::
::I am referring specifically to my very earlier mentioned caveat of :
::
::
::
::Somewhere back in your threads branch offs there was mention of a 7H7 sitting in the RF slot . . . since this set is using 150 ma series string filamental wiring . . .that current starved 7H7 tube would not come up to high enough emission temperature . . so be sure that either a 7C7 or 7B7 ends up in that RF / IF tube slot. . . .which I do think that you confirmed later on.
::
::
::Now we are up to the problem of getting that IF stage operational:
::
::
::
::Lets now proceed in the following mannner:
::
::
::You had success in monitoring the output of the RF and Mixer stages by the capacitive coupling of the mixer plates signal to the transistor "monitor " receiver tuned to the second harmonic of 455Khz (910 Khz).
::
::
::You professed of satisfactory reception of a CBC station ( but not of its AM xmit frequency ? . . . those CBC's affiliates are a l l l l l over Canada. )
::
::
::Also, you were having problems in the sub in of a multitude of other "test" 455 IF transformers for your sets 2nd IF transformer.
::
::
::I have done this many times and usually just lay the transformer close to the bottom of the chassis side of the IF section and use either the transformers leads or solder tack on some test jumper leads to the transformers.
::terminals of newer or smaller units .
::
::
::Now you have already seen that the "radiating" terminal of an IF transformer is its plate connected terminal, so THAT lead, is the one that you want to keep any excess wire lead length to a MINIMUM on.
::
::
::Also run a short leaded clip lead from the case of the subbed in IF transformer to chassis ground.
::
::
::Now move back to the situation of hooking up the monitoring transistor radio to the plate of the Mixer tube by capacitive coupling . . . and getting that CBC station coming in again . . . as well as it was received previously.
::
::
::Now we need . . . minimally . . . to only have the plate winding and B+ supply connection to the subbed in IF transformer being wired in.
::
::
::You THEN take the previously connected jumper from the plate of the Mixer, and move it to the plate connection of the IF amplifier tube.
::
::
::I am now expecting a STROOONNNNG signal to be coming from that transistor "monitor" . . . as was being compared to the previously demonstrated "naked" mixer output signal.
::
::
::If successful . . . run a test on the rest of all of your IF transformers . . . . pick the best one . . . if such is apparent ?
::
::
::
::Now . . . . Standing by for your test evaluation . . . .
::
::
::
::
::
::
::
::
::
::73's de Edd
::
::
::
::
::
::
::
::
::
:::I will confirm but, I can tune it up and as I turn the vernier dial I can hear where the stations should be because it makes a noise where each station would be but does not produce audio just a quick chirp. I wonder if the detector tube could be now bad?
:::
:::
::
::
:::
::::Bubba,
::::
::::Make sure you have the unit wired in correctly. After hooking the transformer up, make sure you have plate voltage on the last IF tube. Under references and color code gives the color for the old style IF transformer leads. If your transformers have solder tabs instead of leads, use an ohmmeter to verify the primary and secondary leads otherwise one may wire a primary lead and a secondary lead to the plate and B+ of the IF tube circuit and the same for the second detector diode and volume control. That wouldn't work.
::::
::::Clifton
::::
::::
::
::
::
::
:::::Damn,, I think you guys may be right. But I had radio right before I unhooked the original can and started trying these replacements. Could anything else go wrong? I will test the tubes again and take voltages after I put a replacement 455 Can in the right spot not using alligator clips.. Thanx for the input..
:::::
::
:::::
:::::
::::::Hi Bubba,
:::::: I am in agreement with Clifton. You have something other than the IF as a problem.
:::::: Time to look beyond the can.
::::::
::::::Best Regards,
::::::
::::::Bill Grimm
::::::
:::::
:::::
::::
::::
:::
:::
::
::
:
:
It must be a much bigger deal when it gets to the output stage?
Bubba
:Bubba,
:
:Assuming the transformer lead colors are blue (or white) for the last IF tube plate, red for the B+, green for the diode plate in the second detector and brown or black for the diode return. I would keep the IF plate and B+ leads away from the diode and return leads as far as possible. You might get some idea by looking at the wires coming out of the first IF transformer and how they are routed thru the chassis.
:
:Clifton
:
:
:
:
::"You professed of satisfactory reception of a CBC station ( but not of its AM xmit frequency ? . . . those CBC's affiliates are a l l l l l over Canada.)"
::
::
::(between here>>>>>>>>>>>>>>>>>)
::
::I had full working radio with original, "half hand wound" 2nd IF and I had just replaced 7H7 and other 7B7 with swap outs for the museum... The Philco then ran for about 1 hour working with full operation.... Then all I was going to do was replace the IF transformer with a proper one,, and when I did, I could not get Radio Audio back again. One point of interest is where the holes are in the metal chassis that let the wires through to the circuitry, under the 2nd IF can when I pulled the wires out (I noticed that there were 3 holes in the chassis) 1 wire had it's own hole and 2 (I think) were shared by 2 wires.. I should have taken a photo but now I cannot remember which colors were where and I wonder if this having the wrong wires too close together may be stopping the IF replacments from working and also oscillating. I would guess that I need to keep the Plate and B- away from the others?
::
::I will look at photos I did take to see if I can figure out what holes had what color wires.. Then I will wire in Txformer and do above..
::
::THX Ed..
::
::
:: (And here>>>>>>>>>>>>>>>>>>>>>)
::
::Also, you were having problems in the sub in of a multitude of other "test" 455 IF transformers for your sets 2nd IF transformer.
::
::
::
::
::
::
::
:::
:::
:::
:::
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:::Sir Bubba. . . . .
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:::Know whut I "thanks" . . .
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:::That basically . . . you had your Philco unit that was working well enough to have an audio section operational enough, and to be able to let it "sound off" with the the amplified stray 60/120 cycle signal that was injected into the volume controls high side.
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:::Your further exploration then revealed a long time dead, crystal cartridge being in the phonos tone arm.
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:::That then brings you up to the testing of the units non existant radio performance.
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:::Now if the unit had a missing tube(s) or the improper ones installed . . . either by you or by someone in the past . . . that tends to explain the fallacy of the RF aspect of the radio not operating.
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:::I am referring specifically to my very earlier mentioned caveat of :
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:::Somewhere back in your threads branch offs there was mention of a 7H7 sitting in the RF slot . . . since this set is using 150 ma series string filamental wiring . . .that current starved 7H7 tube would not come up to high enough emission temperature . . so be sure that either a 7C7 or 7B7 ends up in that RF / IF tube slot. . . .which I do think that you confirmed later on.
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:::Now we are up to the problem of getting that IF stage operational:
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:::Lets now proceed in the following mannner:
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:::You had success in monitoring the output of the RF and Mixer stages by the capacitive coupling of the mixer plates signal to the transistor "monitor " receiver tuned to the second harmonic of 455Khz (910 Khz).
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:::You professed of satisfactory reception of a CBC station ( but not of its AM xmit frequency ? . . . those CBC's affiliates are a l l l l l over Canada. )
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:::Also, you were having problems in the sub in of a multitude of other "test" 455 IF transformers for your sets 2nd IF transformer.
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:::I have done this many times and usually just lay the transformer close to the bottom of the chassis side of the IF section and use either the transformers leads or solder tack on some test jumper leads to the transformers.
:::terminals of newer or smaller units .
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:::Now you have already seen that the "radiating" terminal of an IF transformer is its plate connected terminal, so THAT lead, is the one that you want to keep any excess wire lead length to a MINIMUM on.
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:::Also run a short leaded clip lead from the case of the subbed in IF transformer to chassis ground.
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:::Now move back to the situation of hooking up the monitoring transistor radio to the plate of the Mixer tube by capacitive coupling . . . and getting that CBC station coming in again . . . as well as it was received previously.
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:::Now we need . . . minimally . . . to only have the plate winding and B+ supply connection to the subbed in IF transformer being wired in.
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:::You THEN take the previously connected jumper from the plate of the Mixer, and move it to the plate connection of the IF amplifier tube.
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:::I am now expecting a STROOONNNNG signal to be coming from that transistor "monitor" . . . as was being compared to the previously demonstrated "naked" mixer output signal.
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:::If successful . . . run a test on the rest of all of your IF transformers . . . . pick the best one . . . if such is apparent ?
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:::Now . . . . Standing by for your test evaluation . . . .
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:::73's de Edd
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::::I will confirm but, I can tune it up and as I turn the vernier dial I can hear where the stations should be because it makes a noise where each station would be but does not produce audio just a quick chirp. I wonder if the detector tube could be now bad?
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:::::Bubba,
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:::::Make sure you have the unit wired in correctly. After hooking the transformer up, make sure you have plate voltage on the last IF tube. Under references and color code gives the color for the old style IF transformer leads. If your transformers have solder tabs instead of leads, use an ohmmeter to verify the primary and secondary leads otherwise one may wire a primary lead and a secondary lead to the plate and B+ of the IF tube circuit and the same for the second detector diode and volume control. That wouldn't work.
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:::::Clifton
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::::::Damn,, I think you guys may be right. But I had radio right before I unhooked the original can and started trying these replacements. Could anything else go wrong? I will test the tubes again and take voltages after I put a replacement 455 Can in the right spot not using alligator clips.. Thanx for the input..
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:::::::Hi Bubba,
::::::: I am in agreement with Clifton. You have something other than the IF as a problem.
::::::: Time to look beyond the can.
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:::::::Best Regards,
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:::::::Bill Grimm
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Will update upon firing up.
:Bubba,
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:Make sure you have the unit wired in correctly. After hooking the transformer up, make sure you have plate voltage on the last IF tube. Under references and color code gives the color for the old style IF transformer leads. If your transformers have solder tabs instead of leads, use an ohmmeter to verify the primary and secondary leads otherwise one may wire a primary lead and a secondary lead to the plate and B+ of the IF tube circuit and the same for the second detector diode and volume control. That wouldn't work.
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:Clifton
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::Damn,, I think you guys may be right. But I had radio right before I unhooked the original can and started trying these replacements. Could anything else go wrong? I will test the tubes again and take voltages after I put a replacement 455 Can in the right spot not using alligator clips.. Thanx for the input..
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:::Hi Bubba,
::: I am in agreement with Clifton. You have something other than the IF as a problem.
::: Time to look beyond the can.
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:::Best Regards,
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:::Bill Grimm
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Why am I getting chirping where radio stations should be but no AUDIO??
ANOYYINGGG...
:After having the flu for about 1 week I am back at this. Just shortened the leads and seperated the Plate and B+ leads far away from the rest. Also the Audio lead far away the other way. Soldering in the new IF txformer..
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:Will update upon firing up.
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::Bubba,
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::Make sure you have the unit wired in correctly. After hooking the transformer up, make sure you have plate voltage on the last IF tube. Under references and color code gives the color for the old style IF transformer leads. If your transformers have solder tabs instead of leads, use an ohmmeter to verify the primary and secondary leads otherwise one may wire a primary lead and a secondary lead to the plate and B+ of the IF tube circuit and the same for the second detector diode and volume control. That wouldn't work.
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::Clifton
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:::Damn,, I think you guys may be right. But I had radio right before I unhooked the original can and started trying these replacements. Could anything else go wrong? I will test the tubes again and take voltages after I put a replacement 455 Can in the right spot not using alligator clips.. Thanx for the input..
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::::Hi Bubba,
:::: I am in agreement with Clifton. You have something other than the IF as a problem.
:::: Time to look beyond the can.
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::::Best Regards,
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::::Bill Grimm
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:Can I just get any 455 2nd IF transformer rated for a tube amp? and put it in? I will put the 2 x 100pF and 47K outside (or inside) the can if I need to.
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:Any thoughts or tips? Any type of caps better than others? Does the ohm rating matter? I think the current one is about 20 ohms per side...
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:THX
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