I turned on my, almost always in use, Philco 37-665B when I noticed the volume started quickly dropping just after powering on. I first rotated the volume pot from side to side without effect. I them looked inside the radio to see if any tubes weren't glowing right. I then allowed the tubes to cool then rocked all the tubes from side-to-side. Powered on and radio worked as it should. Relief!!!

Must have been a ghost! Wooooooo :)

*** Update ***

It started slowly losing volume again. This time no amount of tube movement would restore operation.Turn it on and as it warms up the volume drops. Turn volume level high and get distortion. Woe is me!!!

Has it been recapped? If not do that. Test the tubes. If that works it might be wise to look for/change off tolerance resistors next. After that get a can of freeze spray and see what will return it to normal when cooled.

Check the first E-Cap after the rectifier tube. It may be getting :"soft". These need to handle a lot of ripple current.

Caps were replaced previously.

Took my baby to a regular repairman. Checked both output tubes: BAD. Suspect at least one out of tolerance resister as well. It may be months and lots of bux before she comes home again. Walter tried hard but is inundated with stereo consoles and phonographs. Poor man works his tail off! Sure wish I could help.

BTW Working on restoring either a 8S154 or a 10S130 Zenith. I got planes and radios on the brain!