Hi, I was wondering if semi fixed condensers ie: 1650 mfd & 3500 mfd can be replace with new style condensers. I'm not getting any reading off the 3500 with a cap checker and on the 1600 it is all over the scale on the cap checker and reading a short with a ohm meter. The radio starts playing fine for a couple minutes then it gets real loud and then drops volume way down until you touch the grid wire on the 6A8G tube. The volume comes back quite a bit lower than it should be and after a few minutes it drops down even lower with a lot of static. Checked the RF air coils they seem to be fine. Replaced most of the caps and resistors. There are 2 resistors and a mica cap in the same area as the fixed condensers they are within tolerance. These parts are 10, 11, 21, 17, and 20 on the schematic. The chassis is a code 122. Thank You, George.

George, does this problem occur on all bands?

Normally, if touching the det grid cap makes a radio come to life, that is an indication of a problem in the antenna section. But your symptoms are a bit more complicated.

Here's the schematic: http://www.nostalgiaair.org/PagesByModel/209/M0013209.pdf
Doug

:Hi, I was wondering if semi fixed condensers ie: 1650 mfd & 3500 mfd can be replace with new style condensers. I'm not getting any reading off the 3500 with a cap checker and on the 1600 it is all over the scale on the cap checker and reading a short with a ohm meter. The radio starts playing fine for a couple minutes then it gets real loud and then drops volume way down until you touch the grid wire on the 6A8G tube. The volume comes back quite a bit lower than it should be and after a few minutes it drops down even lower with a lot of static. Checked the RF air coils they seem to be fine. Replaced most of the caps and resistors. There are 2 resistors and a mica cap in the same area as the fixed condensers they are within tolerance. These parts are 10, 11, 21, 17, and 20 on the schematic. The chassis is a code 122. Thank You, George.

Hi Doug,
If you touch the 6A8G grid cap it does get better but the volume continues to drop off to practicaly nothing with lots of static, it does this on all bands. The radio played perfectly for at least two years with lots of use. One other thing I noticed is if you are touching the grid cap and then touch the chassis with your other hand the sound goes away completely. Thanks, George.

If the same problem occurs on all bands, you can eliminate any components that are switched out, depending upon the band. It seems most of the compenents you are concerned about fit into this category?

The schmatic lists voltages at the various tube socket pins. Check them when the set is acting up. Start with the 6A8 and work forward through the stages.
Doug
:Hi Doug,
:If you touch the 6A8G grid cap it does get better but the volume continues to drop off to practicaly nothing with lots of static, it does this on all bands. The radio played perfectly for at least two years with lots of use. One other thing I noticed is if you are touching the grid cap and then touch the chassis with your other hand the sound goes away completely. Thanks, George.
:

Thanks Doug,
I just got a 1946 Westinghouse going last night and it did basically the same thing after it warmed up. It was one of the IF transformers I had to adjust it and it is fine now. Just wondering if that might be the problem with the 37-610. The Westinghouse doesn't have a grid cap. Well I have to put the 610 back together and dig a little deeper. Thanks Again, George.