Tram D201 Audio Problem

[mastervipertech]

I have acquired this radio from a long time friend that had used it and stored it for many years.
upon initial fire up I had all tubes lighting and no audio on receive or transmit. I did not put a watt meter on it but it did throw a carrier over my bench receiver. The meter on fire up would go forward then lay back down for a few seconds and then go almost all the way forward on the meter and stay there.
After this I replaced all tubes on the audio board and 401 and 402 on the receiver board. on fire up nothing changed.
I removed the Audio BA board which had been worked on prior by another tech years past and found he had replaced the resistors with four watt and put a replaceable fuse on the board. I replaced every component on the board except C449 and replaced board on fire up I could smell the heat near the board and a slight smoke trail I did a shut down it did not take out the 1/3rd amp fuse and I pulled the board again and saw nothing wrong other than C3 and C2 started pushing the tops.
Any ideas or Direction to go in from this point would be appreciated.

[Sandbagger]

Sept 5, 2010 10:24:15 GMT -5 mastervipertech said:

I have acquired this radio from a long time friend that had used it and stored it for many years.
upon initial fire up I had all tubes lighting and no audio on receive or transmit. I did not put a watt meter on it but it did throw a carrier over my bench receiver. The meter on fire up would go forward then lay back down for a few seconds and then go almost all the way forward on the meter and stay there.
After this I replaced all tubes on the audio board and 401 and 402 on the receiver board. on fire up nothing changed.
I removed the Audio BA board which had been worked on prior by another tech years past and found he had replaced the resistors with four watt and put a replaceable fuse on the board. I replaced every component on the board except C449 and replaced board on fire up I could smell the heat near the board and a slight smoke trail I did a shut down it did not take out the 1/3rd amp fuse and I pulled the board again and saw nothing wrong other than C3 and C2 started pushing the tops.
Any ideas or Direction to go in from this point would be appreciated.

The Tram D201 is a monster when it comes to restoration. There are .22uf caps that tend to short, filter and other electrolytic caps that should be replaced, resistors which change value from long hours of use dropping a good bit of current, and intermittent tube sockets from the heat of the tube pins.

The "BA" board's primary duty is as the 14V regulator. There are also the cathode resistors for the audio output tube and voltage dropping resistors for the relay circuit. There is also one of those infamous .22uF caps that likes to short. If it does, the 10K ohm resistors will run very warm and the relay won't key when you hit the mic PTT.

Also check for lifted circuit traces and bad connections around the tube sockets. And test the tubes and replace any that are weak or show gas or short conditions.

Any caps that show bulging tops should be replaced as that is a sure sign of gas buildup due to leakage.

The S meter has a zero adjustment which will have to be readjusted when the tubes are replaced.