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Drip edge Bassman head.
Friend picked this up fairly cheap. Amp has had a rough life, previous owner had used it as a mod platform over the years and has many circuits through it and many holes drilled in it. Original fiberboard circuit was gone, it was basically bought as a chassis, cabinet, and iron. Power transformer, output and choke are original. My question involves the power transformer. I can smell it was burning, if many years ago, and i can see arc and carbon burn marks on the output tube sockets. I made a transformer test fixture to test unknown trannys, it has AC in, choice of 5y3 or solid state bridge, a 8K load and a 4K load. If i hook up this trans to the HV test, i can draw 150ma or more and have no problems. The filaments are the problem. It is 6.3vac unloaded, which seems low, line voltage is ~122. Putting a 3 or 4 ohm resistor (to draw ~2 amps) across the filament makes it drop to 5.9vac, it is rated at 3.15a. Pictures below, has it overheated and caused damage? I told the guy looks like it is bad.
Friend picked this up fairly cheap. Amp has had a rough life, previous owner had used it as a mod platform over the years and has many circuits through it and many holes drilled in it. Original fiberboard circuit was gone, it was basically bought as a chassis, cabinet, and iron. Power transformer, output and choke are original. My question involves the power transformer. I can smell it was burning, if many years ago, and i can see arc and carbon burn marks on the output tube sockets. I made a transformer test fixture to test unknown trannys, it has AC in, choice of 5y3 or solid state bridge, a 8K load and a 4K load. If i hook up this trans to the HV test, i can draw 150ma or more and have no problems. The filaments are the problem. It is 6.3vac unloaded, which seems low, line voltage is ~122. Putting a 3 or 4 ohm resistor (to draw ~2 amps) across the filament makes it drop to 5.9vac, it is rated at 3.15a. Pictures below, has it overheated and caused damage? I told the guy looks like it is bad.
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