01-08-2013, 09:54 AM
I'm working on a 16B, and have some service info, waiting on other, but there seem to be some production changes (and I have no idea of the code number) that are somewhat confusing.
The main one is in the LO circuit. The schematic and parts layout pages show a 10K resistor from the bottom of the oscillator coil to ground with a capacitor across it. However, there is no such resistor in the radio.
Also in the LO circuit, someone has placed a 37 tube where a 76 is called for. The 76 has a much higher mu than the 37. The alignment is problamatic, plus there is no oscillation on the entire bottom half to 2/3 of the two top bands. I'm ordering a 76 to put in there, hopefully that will help some.
Another problem is the shadow meter. There is a barely perceivable movement with a VERY high level signal, otherwise, it sits in one place, with the lighted portion being about the left 3/8 or so of the target.
If anyone has any suggestions for things I can look for or change out, I would appreciate them.
The main one is in the LO circuit. The schematic and parts layout pages show a 10K resistor from the bottom of the oscillator coil to ground with a capacitor across it. However, there is no such resistor in the radio.
Also in the LO circuit, someone has placed a 37 tube where a 76 is called for. The 76 has a much higher mu than the 37. The alignment is problamatic, plus there is no oscillation on the entire bottom half to 2/3 of the two top bands. I'm ordering a 76 to put in there, hopefully that will help some.
Another problem is the shadow meter. There is a barely perceivable movement with a VERY high level signal, otherwise, it sits in one place, with the lighted portion being about the left 3/8 or so of the target.
If anyone has any suggestions for things I can look for or change out, I would appreciate them.
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