Hi Again, well my 37-610 Big Bullet (workhorse) is having problems. I have listened to this radio every night for 2 or 3 hours and have been doing so for over two years. About 8 months ago it lost some of its volume but still worked fine. It recently started loosing all of its volume after a few minutes of playing. It has been recapped probably sometime in the last ten years judging by the caps used. The electrolyic caps used are 22 mfd's in three places. They should be 8, 12, and 16 mfd's. The funny thing is if I hook a one foot wire up to the grounding cap on the 6A8G Det. Osc. tube top I get most of my volume back. At the same time the regular antenna hook up appears not to be working. The grounding cap comes from the second (rear) variable tuning condenser. I'm fixing to recap the set and replace any out of tolerance resistors. I have duplicate tubes and tried them already with the same out come. Is anybody familier with this problem that could save me a little time and money? I'm kinda new at this stuff and probably know enough to get myself in a world of trouble. Thanks a million, George.

I just worked on a 38-12 where I could only get good reception by touching the grid cap of it as well. Found that the primary of the antenna coil was open. I ended up replacing it with a universal type from AES. You may want to check your coil windings and see if one is open. Other things I would check is the operation on shortwave and making sure the band selector switch is clean to help pinpoint it.

:Hi Again, well my 37-610 Big Bullet (workhorse) is having problems. I have listened to this radio every night for 2 or 3 hours and have been doing so for over two years. About 8 months ago it lost some of its volume but still worked fine. It recently started loosing all of its volume after a few minutes of playing. It has been recapped probably sometime in the last ten years judging by the caps used. The electrolyic caps used are 22 mfd's in three places. They should be 8, 12, and 16 mfd's. The funny thing is if I hook a one foot wire up to the grounding cap on the 6A8G Det. Osc. tube top I get most of my volume back. At the same time the regular antenna hook up appears not to be working. The grounding cap comes from the second (rear) variable tuning condenser. I'm fixing to recap the set and replace any out of tolerance resistors. I have duplicate tubes and tried them already with the same out come. Is anybody familier with this problem that could save me a little time and money? I'm kinda new at this stuff and probably know enough to get myself in a world of trouble. Thanks a million, George.

Agree with Tony. The problem is in the RF ckt, between the antenna and the grid-cap of the detector.

Is the problem on all bands?

Use your ohmmeter and check for continuity through the various RF paths. I think something is open. Another potential problem might be the three caps, labeled 4, 5, and 6, in a bakelite block.
Doug

:I just worked on a 38-12 where I could only get good reception by touching the grid cap of it as well. Found that the primary of the antenna coil was open. I ended up replacing it with a universal type from AES. You may want to check your coil windings and see if one is open. Other things I would check is the operation on shortwave and making sure the band selector switch is clean to help pinpoint it.
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::Hi Again, well my 37-610 Big Bullet (workhorse) is having problems. I have listened to this radio every night for 2 or 3 hours and have been doing so for over two years. About 8 months ago it lost some of its volume but still worked fine. It recently started loosing all of its volume after a few minutes of playing. It has been recapped probably sometime in the last ten years judging by the caps used. The electrolyic caps used are 22 mfd's in three places. They should be 8, 12, and 16 mfd's. The funny thing is if I hook a one foot wire up to the grounding cap on the 6A8G Det. Osc. tube top I get most of my volume back. At the same time the regular antenna hook up appears not to be working. The grounding cap comes from the second (rear) variable tuning condenser. I'm fixing to recap the set and replace any out of tolerance resistors. I have duplicate tubes and tried them already with the same out come. Is anybody familier with this problem that could save me a little time and money? I'm kinda new at this stuff and probably know enough to get myself in a world of trouble. Thanks a million, George.

Thanks Doug and Tony, The problem is on all bands. After a couple minutes of playing the volume goes away. Sometimes you hear a little crackling as the volume is going away. I'm going to rebuild the condenser block and recap the set, also going to replace some of the dogbone resistors they look like they got pretty hot at one time especially the 9000 ohm resistor. Waiting on parts to arrive. There is just one other thing I was wondering about. The set is suppose to have 3 - 110 micas but when I look at the color chart things don't seem to add up. They are the square type but the colors are Blue, unpainted brown, and yellow. They only have the 3 colors the center circle is unpainted brown. One of them had a yellow tubular paralleled with it but there was no info on it and it doesn't show up in the schematic. Anybody have an idea what might have been done. Thanks Again, George.

But the volume still comes back to life when you touch the detector's grid cap? If so, the problem would seem to be in the RF/antenna section between the antenna and the dectector.

Regarding the caps you're trying to identify, can you tell us exactly where on the schematic they are located?
Doug

:Thanks Doug and Tony, The problem is on all bands. After a couple minutes of playing the volume goes away. Sometimes you hear a little crackling as the volume is going away. I'm going to rebuild the condenser block and recap the set, also going to replace some of the dogbone resistors they look like they got pretty hot at one time especially the 9000 ohm resistor. Waiting on parts to arrive. There is just one other thing I was wondering about. The set is suppose to have 3 - 110 micas but when I look at the color chart things don't seem to add up. They are the square type but the colors are Blue, unpainted brown, and yellow. They only have the 3 colors the center circle is unpainted brown. One of them had a yellow tubular paralleled with it but there was no info on it and it doesn't show up in the schematic. Anybody have an idea what might have been done. Thanks Again, George.

Hi Doug,
The volume does come back when I touch the detector grid cap wire. The two micas are numbered 30 and 32 on the schematic and show 110 mmfd they look to be part of the IF trans section. This is a code 122 set. I got the schematic from this site.
Thanks Again,
George

George, I can't imagine how those particular caps would be producing the symptoms that you're describing.

Before you tear into unlikely areas of the set, I recommend that you troubleshoot in a systematic manner. The RF/Antenna section is where I would start.

The set was working until recently, right? So, there is likely just one thing wrong, not a lot of little things.
Doug

:Hi Doug,
:The volume does come back when I touch the detector grid cap wire. The two micas are numbered 30 and 32 on the schematic and show 110 mmfd they look to be part of the IF trans section. This is a code 122 set. I got the schematic from this site.
:Thanks Again,
:George

That sounds like a good idea Doug, being kinda new at this stuff. I'm going to take your advice and run with it. If it ain't broke don't fix it, real words of wisdom. Thanks So Much, George.