[DeleteMe]

I ruled out my antenna hookup when I noticed the radio's sound was getting worse and worse the longer I had it on. I used my sign gen to put an AF signal into the final audio amp and that seemed ok. But when I put it into the 1st audio amp, it was weak and erratic. I was afraid the XXFM tube was bad but didn't have one, so I replaced 6 of the paper caps in that area. Luckily one of them was the culprit. At that point I replaced the rest of the paper caps. 

Then it was time to see how it played. First tried it with no ext antenna. Wow - I'm totally impressed with this Philco radio and its built-in antennas. I don't think I have any radio that works so well in the basement with no outside antenna. No noticeable RF noise either. 

When I do connect my outside antenna, it definitely improves SW reception but seems to introduce some RF noise on the AM band. I'm sure back in the day, an external FM dipole would have been needed here in rural NH for that band. 

After downsizing a couple of years ago, I don't have a good resistor inventory, or I would have checked and replaced some of those. I was up half the night as it was! Are there any particular resistors in these 1940 Philcos that go bad? Of course, right now It's working so well I might be better off leaving it alone.