[tbone]

I did recently replace all three speaker wires as they were in bad shape. Maybe I have a bad solder joint. I'll check the other suggestions as well.

I recently restored one and the hum was not power supply related. The 77 2nd detector shield and tube socket had poor ground to the chassis. By design this radios audio section runs wide open and is susceptible to hum.

The only fix is to clean the shield and mating socket, and top cap with a scotch brite pad for a good ground. Then you need to drill out the socket rivets, clean the area, and use good screws with star washers.

When I was done, the radio was completely quiet. Good luck and Merry Christmas.

Tony