Hi folks,I have a Philco 37-610 tombstone radio that has the volume drop issue that I have heard other people complain about,but have never heard the cause/solution.The radio will sometimes play for days or hours with no problems,but suddenly there will be a pop and the volume will suddenly drop.Sometimes it will come back up in a short time,sometimes it will be several days.Recently,there seems to be no pop before it happens.However ,I have noticed that something turning on in the house will often induce this problem-like a washing machine or my water pump. I have also forced it to retun to normal by unclipping and reclipping the antenna lead.But this does not work that often.This radio has been completely recapped except for the micas.All the resistors have been replaced except for those buried up inside the tuning unit and has had a full alignment.All the tubes have been tested and I have tried substituting tubes.This problem has plagued this radio scince before I did the electronic restoration.I am suspicious of the 110 pf micas in the avc/I.F. filter section,but I have read several times that these never fail.Also,how important is it to use exact values in replacing these 3 particular capacitors?My usual parts supplier carries 100pf and 120pf caps,but not 110.Any thoughts would be greatly appreciated.Thank you.

Hi Mike , have you checked your osc or antenna coils out for a bad connection? I had the same exact problem with a 42-327 philco and it turned out to be the antenna coil that the coil had a corroded terminal causing the radio to "pop out" when ever it felt like, once I cleaned the corrosion off the terminal and coil and re-soldered the problem disapeared. Just a thought...
Elton
:Hi folks,I have a Philco 37-610 tombstone radio that has the volume drop issue that I have heard other people complain about,but have never heard the cause/solution.The radio will sometimes play for days or hours with no problems,but suddenly there will be a pop and the volume will suddenly drop.Sometimes it will come back up in a short time,sometimes it will be several days.Recently,there seems to be no pop before it happens.However ,I have noticed that something turning on in the house will often induce this problem-like a washing machine or my water pump. I have also forced it to retun to normal by unclipping and reclipping the antenna lead.But this does not work that often.This radio has been completely recapped except for the micas.All the resistors have been replaced except for those buried up inside the tuning unit and has had a full alignment.All the tubes have been tested and I have tried substituting tubes.This problem has plagued this radio scince before I did the electronic restoration.I am suspicious of the 110 pf micas in the avc/I.F. filter section,but I have read several times that these never fail.Also,how important is it to use exact values in replacing these 3 particular capacitors?My usual parts supplier carries 100pf and 120pf caps,but not 110.Any thoughts would be greatly appreciated.Thank you.

Elton gave you some good tips especially about the oscillator. A rote solution may not be forth coming. This a really fun problem for logical troubleshooting. Think of it as an opportunity to learn new things. Good luck!

Richard

Mike:
Having repaired thousands of radios over the past 70 years my money is on the second IF circuit. To find out for sure. Place a signal tracer or scope on the the grid of the IF amplifier tube and wait for the drop in volume. If the signal tracer volume remains the same then you isolated the problem to be down the line from the IF amp tube. If your traced signal drops then the trouble is before the IF amp tube. The second IF transfomer and its associated components are notorious for this symptom. Good luck with it. :Hi folks,I have a Philco 37-610 tombstone radio that has the volume drop issue that I have heard other people complain about,but have never heard the cause/solution.The radio will sometimes play for days or hours with no problems,but suddenly there will be a pop and the volume will suddenly drop.Sometimes it will come back up in a short time,sometimes it will be several days.Recently,there seems to be no pop before it happens.However ,I have noticed that something turning on in the house will often induce this problem-like a washing machine or my water pump. I have also forced it to retun to normal by unclipping and reclipping the antenna lead.But this does not work that often.This radio has been completely recapped except for the micas.All the resistors have been replaced except for those buried up inside the tuning unit and has had a full alignment.All the tubes have been tested and I have tried substituting tubes.This problem has plagued this radio scince before I did the electronic restoration.I am suspicious of the 110 pf micas in the avc/I.F. filter section,but I have read several times that these never fail.Also,how important is it to use exact values in replacing these 3 particular capacitors?My usual parts supplier carries 100pf and 120pf caps,but not 110.Any thoughts would be greatly appreciated.Thank you.

Mike,
I've had the same problem with a Majestic (Grigsby-Grunow) model 90B TRF, but without the pop. If I'm patient it returns eventually. Use a Philco 48-460 bakelite table model almost daily without this symptom.

marv

:Hi folks,I have a Philco 37-610 tombstone radio that has the volume drop issue that I have heard other people complain about,but have never heard the cause/solution.The radio will sometimes play for days or hours with no problems,but suddenly there will be a pop and the volume will suddenly drop.Sometimes it will come back up in a short time,sometimes it will be several days.Recently,there seems to be no pop before it happens.However ,I have noticed that something turning on in the house will often induce this problem-like a washing machine or my water pump. I have also forced it to retun to normal by unclipping and reclipping the antenna lead.But this does not work that often.This radio has been completely recapped except for the micas.All the resistors have been replaced except for those buried up inside the tuning unit and has had a full alignment.All the tubes have been tested and I have tried substituting tubes.This problem has plagued this radio scince before I did the electronic restoration.I am suspicious of the 110 pf micas in the avc/I.F. filter section,but I have read several times that these never fail.Also,how important is it to use exact values in replacing these 3 particular capacitors?My usual parts supplier carries 100pf and 120pf caps,but not 110.Any thoughts would be greatly appreciated.Thank you.

Next time it quits, try looking for oscillator action with a digital radio (tune the digital to problem radio IF + frequency tuned on the problem radio). Seems like most of the problems center on the osc ckt. Good luck, rickd
:Mike,
:I've had the same problem with a Majestic (Grigsby-Grunow) model 90B TRF, but without the pop. If I'm patient it returns eventually. Use a Philco 48-460 bakelite table model almost daily without this symptom.
:
:marv
:
::Hi folks,I have a Philco 37-610 tombstone radio that has the volume drop issue that I have heard other people complain about,but have never heard the cause/solution.The radio will sometimes play for days or hours with no problems,but suddenly there will be a pop and the volume will suddenly drop.Sometimes it will come back up in a short time,sometimes it will be several days.Recently,there seems to be no pop before it happens.However ,I have noticed that something turning on in the house will often induce this problem-like a washing machine or my water pump. I have also forced it to retun to normal by unclipping and reclipping the antenna lead.But this does not work that often.This radio has been completely recapped except for the micas.All the resistors have been replaced except for those buried up inside the tuning unit and has had a full alignment.All the tubes have been tested and I have tried substituting tubes.This problem has plagued this radio scince before I did the electronic restoration.I am suspicious of the 110 pf micas in the avc/I.F. filter section,but I have read several times that these never fail.Also,how important is it to use exact values in replacing these 3 particular capacitors?My usual parts supplier carries 100pf and 120pf caps,but not 110.Any thoughts would be greatly appreciated.Thank you.

rickd,
I guess you were addressing Mike's problem. My TRF has neither a local oscillator nor an IF system.

marv

:Next time it quits, try looking for oscillator action with a digital radio (tune the digital to problem radio IF + frequency tuned on the problem radio). Seems like most of the problems center on the osc ckt. Good luck, rickd
::Mike,
::I've had the same problem with a Majestic (Grigsby-Grunow) model 90B TRF, but without the pop. If I'm patient it returns eventually. Use a Philco 48-460 bakelite table model almost daily without this symptom.
::
::marv
::
:::Hi folks,I have a Philco 37-610 tombstone radio that has the volume drop issue that I have heard other people complain about,but have never heard the cause/solution.The radio will sometimes play for days or hours with no problems,but suddenly there will be a pop and the volume will suddenly drop.Sometimes it will come back up in a short time,sometimes it will be several days.Recently,there seems to be no pop before it happens.However ,I have noticed that something turning on in the house will often induce this problem-like a washing machine or my water pump. I have also forced it to retun to normal by unclipping and reclipping the antenna lead.But this does not work that often.This radio has been completely recapped except for the micas.All the resistors have been replaced except for those buried up inside the tuning unit and has had a full alignment.All the tubes have been tested and I have tried substituting tubes.This problem has plagued this radio scince before I did the electronic restoration.I am suspicious of the 110 pf micas in the avc/I.F. filter section,but I have read several times that these never fail.Also,how important is it to use exact values in replacing these 3 particular capacitors?My usual parts supplier carries 100pf and 120pf caps,but not 110.Any thoughts would be greatly appreciated.Thank you.

Good suggestions by all. I strongly recommend checking those micas. I´m not familiar with your set, but I know of several instances where supposed micas have caused me trouble. Sometimes they are paper condensers in disguise. Sometimes the connection goes bad in a mica condenser if it is the real thing. Turning on and off lights can cause voltage surges within amplification circuits (RF circuits) that can make and break bad connections and/or shorts/arcs/leaks, etc. My favorite method of testing any suspicious condenser is to connect it in series with a volt meter and a 200 or 300 volt DC source. This will reveal arcing. It won´t necessarily reveal poor internal connections.

Also, any other poor connection can perform in the same way. It can cause the radio´s sensitivity to come and go at will, and sometimes voltage surges within circuits due to strong and sharp signals (like the pop created by turning on a light) can change the characteristics of the poor connection. Turning on and off a light won´t necessarily change the condition of the poor connection every time. The poor connection can be anywhere in the wiring, in a component, or in a tube, such as the solder connections at a tube´s base.

Good luck. My Philco 60 has the same problem, though probably more frequent. Signal strength comes and goes often (perhaps twice a minute...sometimes more...sometimes less). This is simply because I´ve only replaced the tone condensers in this set. All other condensers (besides electrolytics) are original, and most are leaky...probably with varying amounts of arcing, etc. When I get the time, I`m going to dig out all the bakelite units and replace all of the condensers.

Thomas