Hi, guys,
I picked up a homebrewed amp at the flea market last weekend. It's a 2 tube sweep tube amp with 6JS6C tubes in it. It uses a 6BQ5 tube as the keying circuit. It has the regular 110V power cord on it, but also has another cord coming out the back. That cord had about 24V on standby, and about 142V on operate. It is hooked to the operate/standby switch on one wire, and the transformer on the other wire. I hooked the amp up, and keyed my mic, but the relay does not close. The tubes are lit, and they all test OK, but nothing is happening. Does anyone have any ideas as to what the extra wires are for, and why the amp doesn't key up? Could it be a burned up relay coil? The amp is crammed into a 6" X 6" X 8" cabinet, and it's almost impossible to see what is going on down inside. I can only pull the bottom of the cabinet down about an inch, and can only see a limited amount of components. If I can get the amp working, I'm going to put it in a different cabinet, but I don't want to tear the thing apart right now. Any ideas? Lew
I picked up a homebrewed amp at the flea market last weekend. It's a 2 tube sweep tube amp with 6JS6C tubes in it. It uses a 6BQ5 tube as the keying circuit. It has the regular 110V power cord on it, but also has another cord coming out the back. That cord had about 24V on standby, and about 142V on operate. It is hooked to the operate/standby switch on one wire, and the transformer on the other wire. I hooked the amp up, and keyed my mic, but the relay does not close. The tubes are lit, and they all test OK, but nothing is happening. Does anyone have any ideas as to what the extra wires are for, and why the amp doesn't key up? Could it be a burned up relay coil? The amp is crammed into a 6" X 6" X 8" cabinet, and it's almost impossible to see what is going on down inside. I can only pull the bottom of the cabinet down about an inch, and can only see a limited amount of components. If I can get the amp working, I'm going to put it in a different cabinet, but I don't want to tear the thing apart right now. Any ideas? Lew