A 6-66 is categorized as 'ole ???
The only electrolytic I see isdesignated as a C 20 canned unit , with its common negative connection(s) being at the very bottom and the designated square terminal either stamped or cut into the phenolic base disk is a 40 ufd usedf as the input capacitor.
The triangular marked is its 30 ufd section.
Its not utilizing a cathode bypas at the AF output amp...so thats the total electrolytic complement.
I typically would want to be using a 250 VDC rating....upward for a degree of voltage cushioning.
73's de Edd
:I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
Another aside question, is if the pilot light is lighting up ?
On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
Get about a foot test lead with clips and connect one lead to the radios ground buss line that
terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
Did the hum disappear during that duration ?
Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
Did the hum disappear during that duration ?
If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
stages of testing.
Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
And then the forward your DC voltage and AC ripple readings to us.
The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
Talk to us ….
73's de Edd
:::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
:
:Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:
:With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
:
:Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
:Another aside question, is if the pilot light is lighting up ?
:
:On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
:To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
:
:Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
:
:Get about a foot test lead with clips and connect one lead to the radios ground buss line that
:terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
:
:Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
:
:Did the hum disappear during that duration ?
:
:Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
:
:Did the hum disappear during that duration ?
:
:If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
:
:
:Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
:stages of testing.
:
:
:Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
:
:Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
:
:Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
:
:And then the forward your DC voltage and AC ripple readings to us.
:The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
:
:Talk to us ….
:
:
:
:73's de Edd
:
:
:
:
:
:
::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
::
::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
::
::
::
::
::
::
::
::
::
::
::
::
::
::
::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
::
::
::
::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
::
::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
::Another aside question, is if the pilot light is lighting up ?
::
::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
::
::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
::
::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
::
::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
::
::Did the hum disappear during that duration ?
::
::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
::
::Did the hum disappear during that duration ?
::
::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
::
::
::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
::stages of testing.
::
::
::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
::
::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
::
::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
::
::And then the forward your DC voltage and AC ripple readings to us.
::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
::
::Talk to us ….
::
::
::
::73's de Edd
::
::
::
::
::
::
:::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
:::
:::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
:::
:::
:::
:::
:::
:::
:::
:::
:::
:::
:::
:::
:::
:::
Too easy, but, You couldn't have a dirty / bad volume control could you ?
73's de Edd
:STILL working on this crazy thing. Haven't given up YET! I've almost got this thing,BUT still can't lower channels to tune in...static, UNLESS I fool jiggle any of the three knobs. Then I can get a lower station but it fades away quickly. Sounds like I may be looking for another bad connection or I have something going to ground that shouldn't? Best place to start looking or should I be looking at components?? Help,help, help!!!
:::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
:::
:::
:::
:::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
:::
:::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
:::Another aside question, is if the pilot light is lighting up ?
:::
:::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
:::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
:::
:::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
:::
:::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
:::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
:::
:::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
:::
:::Did the hum disappear during that duration ?
:::
:::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
:::
:::Did the hum disappear during that duration ?
:::
:::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
:::
:::
:::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
:::stages of testing.
:::
:::
:::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
:::
:::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
:::
:::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
:::
:::And then the forward your DC voltage and AC ripple readings to us.
:::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
:::
:::Talk to us ….
:::
:::
:::
:::73's de Edd
:::
:::
:::
:::
:::
:::
::::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
::::
::::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
::::
::::
::::
::::
::::
::::
::::
::::
::::
::::
::::
::::
::::
::::
:
:
:
:Too easy, but, You couldn't have a dirty / bad volume control could you ?
:
:
:73's de Edd
:
:
:
:
:
::STILL working on this crazy thing. Haven't given up YET! I've almost got this thing,BUT still can't lower channels to tune in...static, UNLESS I fool jiggle any of the three knobs. Then I can get a lower station but it fades away quickly. Sounds like I may be looking for another bad connection or I have something going to ground that shouldn't? Best place to start looking or should I be looking at components?? Help,help, help!!!
::::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
::::
::::
::::
::::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
::::
::::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
::::Another aside question, is if the pilot light is lighting up ?
::::
::::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
::::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
::::
::::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
::::
::::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
::::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
::::
::::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
::::
::::Did the hum disappear during that duration ?
::::
::::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
::::
::::Did the hum disappear during that duration ?
::::
::::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
::::
::::
::::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
::::stages of testing.
::::
::::
::::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
::::
::::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
::::
::::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
::::
::::And then the forward your DC voltage and AC ripple readings to us.
::::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
::::
::::Talk to us ….
::::
::::
::::
::::73's de Edd
::::
::::
::::
::::
::::
::::
:::::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
:::::
:::::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
:::::
::Hadn't even thought of that but will tomorrow!! I'm also on the trail of some real antenna wire for these old things..can't even get a nibble evry place I've looked. Bet you know where to get some or the best thing to use!
::
::
::
::Too easy, but, You couldn't have a dirty / bad volume control could you ?
::
::
::73's de Edd
::
::
::
::
::
:::STILL working on this crazy thing. Haven't given up YET! I've almost got this thing,BUT still can't lower channels to tune in...static, UNLESS I fool jiggle any of the three knobs. Then I can get a lower station but it fades away quickly. Sounds like I may be looking for another bad connection or I have something going to ground that shouldn't? Best place to start looking or should I be looking at components?? Help,help, help!!!
:::::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
:::::
:::::
:::::
:::::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
:::::
:::::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
:::::Another aside question, is if the pilot light is lighting up ?
:::::
:::::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
:::::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
:::::
:::::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
:::::
:::::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
:::::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
:::::
:::::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
:::::
:::::Did the hum disappear during that duration ?
:::::
:::::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
:::::
:::::Did the hum disappear during that duration ?
:::::
:::::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
:::::
:::::
:::::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
:::::stages of testing.
:::::
:::::
:::::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
:::::
:::::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
:::::
:::::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
:::::
:::::And then the forward your DC voltage and AC ripple readings to us.
:::::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
:::::
:::::Talk to us ….
:::::
:::::
:::::
:::::73's de Edd
:::::
:::::
:::::
:::::
:::::
:::::
::::::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
::::::
::::::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
Sounds like you are up to par on the reception of the AM broadcast band with the external antenna wire hopping up its performance.Since this receiver is not using a back of the set exposed spiderwound loop antenna, but an under chassis shielded L1 antenna coil
The short wave is even more critical on the need of that longer external antenna wire as its L2 antenna coil is also sitting down there ALL SHIELDED by the metal chassis, it just FLAT doesn't get any signal unless it is piped into it through via an external antenna wire !
Also, short wave reception is from weak distant signals and the reception time and the fact that different bands have peak performance at certain hours is all critical. At different times of the day, you should be able to get the primary 41-31-25-22-19 and 16 Meter foreign radio broadcast stations, as well as some ham bands..though just about all them are SSB operational mode nowadays.
73's de Edd
:I think I may have an antenna problem!!I tried a variety of antennas with varied results of course. Right now, I have bare stranded connected to the external antenna location and the AM gets a jillion stations, but the sw remains weaker than desired??
:::Hadn't even thought of that but will tomorrow!! I'm also on the trail of some real antenna wire for these old things..can't even get a nibble evry place I've looked. Bet you know where to get some or the best thing to use!
:::
:::
:::
:::Too easy, but, You couldn't have a dirty / bad volume control could you ?
:::
:::
:::73's de Edd
:::
:::
:::
:::
:::
::::STILL working on this crazy thing. Haven't given up YET! I've almost got this thing,BUT still can't lower channels to tune in...static, UNLESS I fool jiggle any of the three knobs. Then I can get a lower station but it fades away quickly. Sounds like I may be looking for another bad connection or I have something going to ground that shouldn't? Best place to start looking or should I be looking at components?? Help,help, help!!!
::::::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
::::::
::::::
::::::
::::::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
::::::
::::::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
::::::Another aside question, is if the pilot light is lighting up ?
::::::
::::::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
::::::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
::::::
::::::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
::::::
::::::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
::::::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
::::::
::::::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
::::::
::::::Did the hum disappear during that duration ?
::::::
::::::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
::::::
::::::Did the hum disappear during that duration ?
::::::
::::::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
::::::
::::::
::::::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
::::::stages of testing.
::::::
::::::
::::::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
::::::
::::::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
::::::
::::::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
::::::
::::::And then the forward your DC voltage and AC ripple readings to us.
::::::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
::::::
::::::Talk to us ….
::::::
::::::
::::::
::::::73's de Edd
::::::
::::::
::::::
::::::
::::::
::::::
:::::::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
:::::::
:::::::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
:
:
:
:
:Sounds like you are up to par on the reception of the AM broadcast band with the external antenna wire hopping up its performance.Since this receiver is not using a back of the set exposed spiderwound loop antenna, but an under chassis shielded L1 antenna coil
:
:The short wave is even more critical on the need of that longer external antenna wire as its L2 antenna coil is also sitting down there ALL SHIELDED by the metal chassis, it just FLAT doesn't get any signal unless it is piped into it through via an external antenna wire !
:
:Also, short wave reception is from weak distant signals and the reception time and the fact that different bands have peak performance at certain hours is all critical. At different times of the day, you should be able to get the primary 41-31-25-22-19 and 16 Meter foreign radio broadcast stations, as well as some ham bands..though just about all them are SSB operational mode nowadays.
:
:
:73's de Edd
:
:
:
:
:
:
:
:
:
::I think I may have an antenna problem!!I tried a variety of antennas with varied results of course. Right now, I have bare stranded connected to the external antenna location and the AM gets a jillion stations, but the sw remains weaker than desired??
::::Hadn't even thought of that but will tomorrow!! I'm also on the trail of some real antenna wire for these old things..can't even get a nibble evry place I've looked. Bet you know where to get some or the best thing to use!
::::
::::
::::
::::Too easy, but, You couldn't have a dirty / bad volume control could you ?
::::
::::
::::73's de Edd
::::
::::
::::
::::
::::
:::::STILL working on this crazy thing. Haven't given up YET! I've almost got this thing,BUT still can't lower channels to tune in...static, UNLESS I fool jiggle any of the three knobs. Then I can get a lower station but it fades away quickly. Sounds like I may be looking for another bad connection or I have something going to ground that shouldn't? Best place to start looking or should I be looking at components?? Help,help, help!!!
:::::::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
:::::::
:::::::
:::::::
:::::::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
:::::::
:::::::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
:::::::Another aside question, is if the pilot light is lighting up ?
:::::::
:::::::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
:::::::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
:::::::
:::::::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
:::::::
:::::::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
:::::::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
:::::::
:::::::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
:::::::
:::::::Did the hum disappear during that duration ?
:::::::
:::::::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
:::::::
:::::::Did the hum disappear during that duration ?
:::::::
:::::::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
:::::::
:::::::
:::::::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
:::::::stages of testing.
:::::::
:::::::
:::::::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
:::::::
:::::::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
:::::::
:::::::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
:::::::
:::::::And then the forward your DC voltage and AC ripple readings to us.
:::::::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
:::::::
:::::::Talk to us ….
:::::::
:::::::
:::::::
:::::::73's de Edd
:::::::
:::::::
:::::::
:::::::
:::::::
:::::::
::::::::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
::::::::
::::::::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
Hard to believe that you actually have as many units of that chassis as you do ! This is certainly not one of your units cabinets with the faux brown leatherette cabinet…. is it ? As well, with the rear of the cabinet having this appearance on its physical layout. Any chance that any of yours having the set of Fathnestock clips at the top inside rear of the cabinet ? As for your speaker dilemma, is it a case of an actual sound quality problem or a real ratty looking / torn cone situation?
With 3 of the same chassis to compare against, it certainly seems that you are misreading the routing of the wiring, if you think that you have the antenna input routed into the oscillator coils circuitry .
Check out the thumbnail that I have placed below here, the schema shows the aerial wire coming inside the rear of the chassis thru a hole in its backside and then is connecting to a series wave-trap of coil L5 and cap C10 and THEN the filtered antennas RF input is routed to one of the bandswitch rotor contacts that opts to either connect in to the BC ant coil L1 (in RED) or the SW ant coil (in ORANGE) with the RF signal then eventually routed into another set of band switch contacts with the selected BC or SW signal then going to the RF amp 12SK7’s grid at pin #4.
Looking at the BC and SW oscillator coils shown in yellow and chartreuse, they are in no way connected into the antenna / aerial input circuitry.
Reference:
73's de Edd
::2 out of 3 up and going.Last one could use a new speaker as the one in it is pretty sad and I don't believe original. Any ideas on a replacement??? I've noticed that the external antenna connection is to L4 osc. coil on all 3. ??? Is there a better location to attach the external antennas???
::
::
::
::
::Sounds like you are up to par on the reception of the AM broadcast band with the external antenna wire hopping up its performance.Since this receiver is not using a back of the set exposed spiderwound loop antenna, but an under chassis shielded L1 antenna coil
::
::The short wave is even more critical on the need of that longer external antenna wire as its L2 antenna coil is also sitting down there ALL SHIELDED by the metal chassis, it just FLAT doesn't get any signal unless it is piped into it through via an external antenna wire !
::
::Also, short wave reception is from weak distant signals and the reception time and the fact that different bands have peak performance at certain hours is all critical. At different times of the day, you should be able to get the primary 41-31-25-22-19 and 16 Meter foreign radio broadcast stations, as well as some ham bands..though just about all them are SSB operational mode nowadays.
::
::
::73's de Edd
::
::
::
::
::
::
::
::
::
:::I think I may have an antenna problem!!I tried a variety of antennas with varied results of course. Right now, I have bare stranded connected to the external antenna location and the AM gets a jillion stations, but the sw remains weaker than desired??
:::::Hadn't even thought of that but will tomorrow!! I'm also on the trail of some real antenna wire for these old things..can't even get a nibble evry place I've looked. Bet you know where to get some or the best thing to use!
:::::
:::::
:::::
:::::Too easy, but, You couldn't have a dirty / bad volume control could you ?
:::::
:::::
:::::73's de Edd
:::::
:::::
:::::
:::::
:::::
::::::STILL working on this crazy thing. Haven't given up YET! I've almost got this thing,BUT still can't lower channels to tune in...static, UNLESS I fool jiggle any of the three knobs. Then I can get a lower station but it fades away quickly. Sounds like I may be looking for another bad connection or I have something going to ground that shouldn't? Best place to start looking or should I be looking at components?? Help,help, help!!!
::::::::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
::::::::
::::::::
::::::::
::::::::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
::::::::
::::::::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
::::::::Another aside question, is if the pilot light is lighting up ?
::::::::
::::::::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
::::::::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
::::::::
::::::::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
::::::::
::::::::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
::::::::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
::::::::
::::::::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
::::::::
::::::::Did the hum disappear during that duration ?
::::::::
::::::::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
::::::::
::::::::Did the hum disappear during that duration ?
::::::::
::::::::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
::::::::
::::::::
::::::::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
::::::::stages of testing.
::::::::
::::::::
::::::::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
::::::::
::::::::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
::::::::
::::::::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
::::::::
::::::::And then the forward your DC voltage and AC ripple readings to us.
::::::::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
::::::::
::::::::Talk to us ….
::::::::
::::::::
::::::::
::::::::73's de Edd
::::::::
::::::::
::::::::
::::::::
::::::::
::::::::
:::::::::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
:::::::::
:::::::::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:
:
:
:
:Hard to believe that you actually have as many units of that chassis as you do ! This is certainly not one of your units cabinets with the faux brown leatherette cabinet…. is it ? As well, with the rear of the cabinet having this appearance on its physical layout. Any chance that any of yours having the set of Fathnestock clips at the top inside rear of the cabinet ? As for your speaker dilemma, is it a case of an actual sound quality problem or a real ratty looking / torn cone situation?
:
:
:
:
:
:
:
:
:With 3 of the same chassis to compare against, it certainly seems that you are misreading the routing of the wiring, if you think that you have the antenna input routed into the oscillator coils circuitry .
:
:Check out the thumbnail that I have placed below here, the schema shows the aerial wire coming inside the rear of the chassis thru a hole in its backside and then is connecting to a series wave-trap of coil L5 and cap C10 and THEN the filtered antennas RF input is routed to one of the bandswitch rotor contacts that opts to either connect in to the BC ant coil L1 (in RED) or the SW ant coil (in ORANGE) with the RF signal then eventually routed into another set of band switch contacts with the selected BC or SW signal then going to the RF amp 12SK7’s grid at pin #4.
:Looking at the BC and SW oscillator coils shown in yellow and chartreuse, they are in no way connected into the antenna / aerial input circuitry.
:
:Reference:
:
:
:
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:
:::2 out of 3 up and going.Last one could use a new speaker as the one in it is pretty sad and I don't believe original. Any ideas on a replacement??? I've noticed that the external antenna connection is to L4 osc. coil on all 3. ??? Is there a better location to attach the external antennas???
:::
:::
:::
:::
:::Sounds like you are up to par on the reception of the AM broadcast band with the external antenna wire hopping up its performance.Since this receiver is not using a back of the set exposed spiderwound loop antenna, but an under chassis shielded L1 antenna coil
:::
:::The short wave is even more critical on the need of that longer external antenna wire as its L2 antenna coil is also sitting down there ALL SHIELDED by the metal chassis, it just FLAT doesn't get any signal unless it is piped into it through via an external antenna wire !
:::
:::Also, short wave reception is from weak distant signals and the reception time and the fact that different bands have peak performance at certain hours is all critical. At different times of the day, you should be able to get the primary 41-31-25-22-19 and 16 Meter foreign radio broadcast stations, as well as some ham bands..though just about all them are SSB operational mode nowadays.
:::
:::
:::73's de Edd
:::
:::
:::
:::
:::
:::
:::
:::
:::
::::I think I may have an antenna problem!!I tried a variety of antennas with varied results of course. Right now, I have bare stranded connected to the external antenna location and the AM gets a jillion stations, but the sw remains weaker than desired??
::::::Hadn't even thought of that but will tomorrow!! I'm also on the trail of some real antenna wire for these old things..can't even get a nibble evry place I've looked. Bet you know where to get some or the best thing to use!
::::::
::::::
::::::
::::::Too easy, but, You couldn't have a dirty / bad volume control could you ?
::::::
::::::
::::::73's de Edd
::::::
::::::
::::::
::::::
::::::
:::::::STILL working on this crazy thing. Haven't given up YET! I've almost got this thing,BUT still can't lower channels to tune in...static, UNLESS I fool jiggle any of the three knobs. Then I can get a lower station but it fades away quickly. Sounds like I may be looking for another bad connection or I have something going to ground that shouldn't? Best place to start looking or should I be looking at components?? Help,help, help!!!
:::::::::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
:::::::::
:::::::::
:::::::::
:::::::::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
:::::::::
:::::::::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
:::::::::Another aside question, is if the pilot light is lighting up ?
:::::::::
:::::::::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
:::::::::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
:::::::::
:::::::::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
:::::::::
:::::::::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
:::::::::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
:::::::::
:::::::::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
:::::::::
:::::::::Did the hum disappear during that duration ?
:::::::::
:::::::::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
:::::::::
:::::::::Did the hum disappear during that duration ?
:::::::::
:::::::::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
:::::::::
:::::::::
:::::::::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
:::::::::stages of testing.
:::::::::
:::::::::
:::::::::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
:::::::::
:::::::::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
:::::::::
:::::::::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
:::::::::
:::::::::And then the forward your DC voltage and AC ripple readings to us.
:::::::::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
:::::::::
:::::::::Talk to us ….
:::::::::
:::::::::
:::::::::
:::::::::73's de Edd
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
:::::::::
::::::::::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
::::::::::
::::::::::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::::::::::
::That's one of them and was by far the easiest to get up and going. The other two are metal and have no grid antenna inside as the the leatherette one does. I have several old spartons that I've picked up because I got a whole bunch of tubes from an ex repairman that fit these models. The two metal ones came with the external antenna hooked up as described so I didn't change the location...but it just didn't seem right to me. One I picked up at the flea market here and the other in an OLD antique shop south of Memphis so it couldn't have been the same person putting the old external antenna connection there????
::
::
::
::
::Hard to believe that you actually have as many units of that chassis as you do ! This is certainly not one of your units cabinets with the faux brown leatherette cabinet…. is it ? As well, with the rear of the cabinet having this appearance on its physical layout. Any chance that any of yours having the set of Fathnestock clips at the top inside rear of the cabinet ? As for your speaker dilemma, is it a case of an actual sound quality problem or a real ratty looking / torn cone situation?
::
::
::
::
::
::
::
::
::With 3 of the same chassis to compare against, it certainly seems that you are misreading the routing of the wiring, if you think that you have the antenna input routed into the oscillator coils circuitry .
::
::Check out the thumbnail that I have placed below here, the schema shows the aerial wire coming inside the rear of the chassis thru a hole in its backside and then is connecting to a series wave-trap of coil L5 and cap C10 and THEN the filtered antennas RF input is routed to one of the bandswitch rotor contacts that opts to either connect in to the BC ant coil L1 (in RED) or the SW ant coil (in ORANGE) with the RF signal then eventually routed into another set of band switch contacts with the selected BC or SW signal then going to the RF amp 12SK7’s grid at pin #4.
::Looking at the BC and SW oscillator coils shown in yellow and chartreuse, they are in no way connected into the antenna / aerial input circuitry.
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::::2 out of 3 up and going.Last one could use a new speaker as the one in it is pretty sad and I don't believe original. Any ideas on a replacement??? I've noticed that the external antenna connection is to L4 osc. coil on all 3. ??? Is there a better location to attach the external antennas???
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::::Sounds like you are up to par on the reception of the AM broadcast band with the external antenna wire hopping up its performance.Since this receiver is not using a back of the set exposed spiderwound loop antenna, but an under chassis shielded L1 antenna coil
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::::The short wave is even more critical on the need of that longer external antenna wire as its L2 antenna coil is also sitting down there ALL SHIELDED by the metal chassis, it just FLAT doesn't get any signal unless it is piped into it through via an external antenna wire !
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::::Also, short wave reception is from weak distant signals and the reception time and the fact that different bands have peak performance at certain hours is all critical. At different times of the day, you should be able to get the primary 41-31-25-22-19 and 16 Meter foreign radio broadcast stations, as well as some ham bands..though just about all them are SSB operational mode nowadays.
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:::::I think I may have an antenna problem!!I tried a variety of antennas with varied results of course. Right now, I have bare stranded connected to the external antenna location and the AM gets a jillion stations, but the sw remains weaker than desired??
:::::::Hadn't even thought of that but will tomorrow!! I'm also on the trail of some real antenna wire for these old things..can't even get a nibble evry place I've looked. Bet you know where to get some or the best thing to use!
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:::::::Too easy, but, You couldn't have a dirty / bad volume control could you ?
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:::::::73's de Edd
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::::::::STILL working on this crazy thing. Haven't given up YET! I've almost got this thing,BUT still can't lower channels to tune in...static, UNLESS I fool jiggle any of the three knobs. Then I can get a lower station but it fades away quickly. Sounds like I may be looking for another bad connection or I have something going to ground that shouldn't? Best place to start looking or should I be looking at components?? Help,help, help!!!
::::::::::Ok, Finally got back to this thing. In going through the tests I found a loose connnection and the hummmm was fixed,but.....can't get many lower stations on am and nothing at all on sw. Volume seems to go up and down and stations seem to come and go. By the way, I have three of these same models. Two are in metal cases and one is in some kind of leather looking material. I have it working fine now on am and sw,but it has another antenna inside atttached to the top. The two metal cased ones do not....thought it was because they are metal???Oh, I also have an 8w10 that I'll be looking at soon....it lights a few tubes but no sound.
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::::::::::With that set having an RF stage, that little puppy should really work quite well, performance wise, once you get it all going right.
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::::::::::Being a common AC-DC design and the unit using R/C power supply filtering, you need to confirm that you had the largest capacitance value making its connection to the buss going to the 35Z5’s pin # 8. Also do a cold set resistance check of R14…1200 ohm 2W… resistor and confirm that it has not cooked down to a lower value with heat and time.
::::::::::Another aside question, is if the pilot light is lighting up ?
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::::::::::On other like sets , I have often seen filtering value pairs of upwards to 80 and 50 ufd used for their like filtering values.
::::::::::To confirm that the hum which you are hearing is coming from power supply filtering, initially try this.
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::::::::::Plug in the set, and get it doing its worse hummmmmmmm, and then do an instant reversal of the sets AC power plug…180 degrees in the outlet…. and see if the hum is better or worse and leave the units plug connected in the position that produces the least hummmm.
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::::::::::Get about a foot test lead with clips and connect one lead to the radios ground buss line that
::::::::::terminates at the negative terminal of the filter(s) which we have been concerned about earlier.
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::::::::::Listen at your hum level and then locate pin #2 of the 12SQ7 1st audio and short it to ground for about 3-5 seconds, using the free end of that ground lead that you had in hand.
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::::::::::Did the hum disappear during that duration ?
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::::::::::Now, move over and locate pin # 5 of the 35L6 audio output tube and perform the same grounding action of that pin while doing an evaluative listening of the hum level present.
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::::::::::Did the hum disappear during that duration ?
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::::::::::If neither test resulted in an abatement of the hum, one could suspicion a need for upping the filtering of the power supply.
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::::::::::Two rare off the wall situations……one being the presence of poor shielding in the earliest AF stage as well as any possible tube cathode to filament leakage BUT, that was just covered by the prior
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::::::::::Another rare possibility of development of shorted turns on the primary of the AF output transformer, but if that is the case, one can expect a warming up of the core and and overall operating temp of the transformer.
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::::::::::Another out of the blue situation might be the past replacement of that AF output transformer by a person in the past with one "on-hand " that had a lower Z + DC resistane than the original unit ……an inspection of the original will probably reveal it still being factory riveted in place…allaying that latter rare possibility.
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::::::::::Lastly… you might take meter in hand and take, and log down, DC voltage readings on either side…input and output side of that R14 filter resistor and then switch metering to AC mode and take a 1 ufd..or more... /200VDC paper capacitor…not electrolytic…. and insert in series with the hot AC metering probe and then measure the AC ripple voltage component that is present at those two points.
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::::::::::And then the forward your DC voltage and AC ripple readings to us.
::::::::::The logic for that DC isolative capacitor was my being non familiar with WHAT type or brand of metering being used…as some brands / types can produce some very SQUIRRELLY readings when any overriding / simultaneous DC component is also present.
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::::::::::Talk to us ….
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::::::::::73's de Edd
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:::::::::::::I don't recognize the symbols used at the e caps on this schematic for positive and negative. So far I have a pretty good ole radio and don't want to mess it up. This a very small chassis and it's pretty congested in that area anyway. Any help???
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:::::::::::Installed all new caps includin e-caps but still have pretty good hum! Not sure,but sounds like I may have 40 and 30 reversed?? Not a hard fix, but am more used to wiring diagrams than schematics. Best solution???
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