06-07-2012, 03:03 PM
This radio was not playing when I got it. I did a complete recapp and checked/replaced resistors as needed. After I got it up on a variac, it played well, volume seemed good. I tuned the IF cans by ear but havent done an alignment yet.
The next day I was playing it on my bench while cleaning up. After a while the volume dropped to a wisper. I looked for bad connections (tap tested tubes and components in case I had a bad joint) but could not locate one. It has remained at low volume since then.
I decided to check voltages today and see if I could locate a problem. All tube voltages are very low. I dont have a tube tester, but have some spare tubes from a parts chassis, so I started subbing tubes in case I had a bad one. One thing I noticed while replacing tubes is when I pulled either 6L6 with the other left in, the volume went up to what seemed normal. Whenever I replaced the tube so both were installed, the volume dropped after a second or two. This happens no matter what socket is empty. The pin voltages are lower than they should be with only one 6L6, but much lower with both of them in.
How should I trouble shoot this? I am still in the learning stage and would like to get this working.
Thanks,
Steve
The next day I was playing it on my bench while cleaning up. After a while the volume dropped to a wisper. I looked for bad connections (tap tested tubes and components in case I had a bad joint) but could not locate one. It has remained at low volume since then.
I decided to check voltages today and see if I could locate a problem. All tube voltages are very low. I dont have a tube tester, but have some spare tubes from a parts chassis, so I started subbing tubes in case I had a bad one. One thing I noticed while replacing tubes is when I pulled either 6L6 with the other left in, the volume went up to what seemed normal. Whenever I replaced the tube so both were installed, the volume dropped after a second or two. This happens no matter what socket is empty. The pin voltages are lower than they should be with only one 6L6, but much lower with both of them in.
How should I trouble shoot this? I am still in the learning stage and would like to get this working.
Thanks,
Steve