[Yesterday: 11 miles; today 30 minutes of rowing]
I was using the Drake 2B receiver that I picked up in KC a couple of weeks ago. It seemed to work fine.
Then I turned it on again and am getting nothing out of it except a slight hum when the volume control is full-on.
I need to do some more troubleshooting, but it looks to me like the audio amplifier is not working. One comment I saw online said the output capacitor has a tendency to fail. It is a 10 uf non-polarized electrolytic. It looks like the other eletrolytics in the receiver have been replaced at one time or another.
I think the thing to do is 1) feed in some generated audio and see if it comes out and 2) look at the grid input of audio amplifier tube with my scope and see if it changes while I tune across the band… maybe I could even grab it at that point and sent it to a different audio amp.
One nice thing about working on tube radios is that you can take the tubes out, or one tube out. Then you can check the inputs and outputs without the tube in the picture.