11-19-2013, 09:15 AM
Just today. Odd, since this is the part that was oversize and came via Parcel Select. The amp chassis arrived in Seoul this afternoon, so I should get that tomorrow.
Minor damage to the preset mech on the back. One side bent in slightly, should be a simple fix.
This one's been totally recapped. They didn't restuff the cans, just disconnected them and installed the new caps. Not a bad job, really. But they missed something: the plate resistor for the RF amp was measuring about 1.3 megohm rather than the 15K called for. Replacing that gave me great gain on AM/BC, but there's a disconnect somewhere between the detector/AVC and the eye tube, as there is no indication whatsoever despite the tube appearing to be almost new. I will put another tube in there and see if there is any difference, just to be sure.
SW is dead. No LO at all. When I switch from BC to SW, the plate voltage drops from ~129 to around 103, but I don't think that would kill it completely. Have to try to figure that one out. Feeding a signal in from my sig gen does result in good reception on the band, so if I can get that LO going, it should do very well. If anyone has experience with this particular problem please feel free to toss in your two cents.
FM seems pretty good on this one. Much better gain than on the other tuner, there's even some white noise between stations as there should be. Still not quite what it should be, though, as it will only partially close the eye tube on a very high signal, it barely moves at all with an average input. I kind of suspect perhaps weak IF tube or tubes. I have some on order, so we'll see on that.
All buttons work properly on this one. Once I get that preset mech bent back into shape, I'll try my hand at setting up some presets. Nice to be able to turn it on and off.
Minor damage to the preset mech on the back. One side bent in slightly, should be a simple fix.
This one's been totally recapped. They didn't restuff the cans, just disconnected them and installed the new caps. Not a bad job, really. But they missed something: the plate resistor for the RF amp was measuring about 1.3 megohm rather than the 15K called for. Replacing that gave me great gain on AM/BC, but there's a disconnect somewhere between the detector/AVC and the eye tube, as there is no indication whatsoever despite the tube appearing to be almost new. I will put another tube in there and see if there is any difference, just to be sure.
SW is dead. No LO at all. When I switch from BC to SW, the plate voltage drops from ~129 to around 103, but I don't think that would kill it completely. Have to try to figure that one out. Feeding a signal in from my sig gen does result in good reception on the band, so if I can get that LO going, it should do very well. If anyone has experience with this particular problem please feel free to toss in your two cents.
FM seems pretty good on this one. Much better gain than on the other tuner, there's even some white noise between stations as there should be. Still not quite what it should be, though, as it will only partially close the eye tube on a very high signal, it barely moves at all with an average input. I kind of suspect perhaps weak IF tube or tubes. I have some on order, so we'll see on that.
All buttons work properly on this one. Once I get that preset mech bent back into shape, I'll try my hand at setting up some presets. Nice to be able to turn it on and off.
