02-07-2021, 09:31 PM
Radioroslyn - I grew tired of waiting for the plastic alignment tool to arrive, so I made a few calls and managed to borrow one. (Unfortunately, the person from whom I borrowed it, inherited it from his father, and he doesn't know a thing about radio repair - so he can't help me.) I'm not able to inject a 460KC at the antenna clip. The lowest frequency that will pass is 560KC - and that is EXTREMELY faint, and adjusting the caps makes no difference. (I do not have a frequency counter, but the generator has always been accurate for past alignments.) However, there appear to be other problems that an alignment is not going to fix:
I decided to take some voltage measurements.
The 42 output is okay.
The 75 P-K is 278 (should be 250) the CG-K is .55(should be .15)
Moving backward, the 78 readings are worse: P-K reads 278 (should be 250). SG-K reads 271 (should be 120) CG-K reads 3.49 (should be.18)
Worst of all is the 6A7. The P-K is 255 (should be 250). That's the only reading I can take, as the digital multimeter jumps all over the place and flashes AC. I realize that incoming signals are AC, (at least that is what I learned) but the Model 60 directions specify DC voltage measurements, with the exception of filament voltages. I must confess that I am only vaguely familiar with a pentagram converter - it appears to be 2 tubes in one. This tube tests okay on my tube tester.
The schematic does not appear all that complicated, but obviously, at this moment, I'm over my head. Any clarification would be greatly appreciated, as would some direction, as to where to begin investigating. Many thanks, in advance.
I decided to take some voltage measurements.
The 42 output is okay.
The 75 P-K is 278 (should be 250) the CG-K is .55(should be .15)
Moving backward, the 78 readings are worse: P-K reads 278 (should be 250). SG-K reads 271 (should be 120) CG-K reads 3.49 (should be.18)
Worst of all is the 6A7. The P-K is 255 (should be 250). That's the only reading I can take, as the digital multimeter jumps all over the place and flashes AC. I realize that incoming signals are AC, (at least that is what I learned) but the Model 60 directions specify DC voltage measurements, with the exception of filament voltages. I must confess that I am only vaguely familiar with a pentagram converter - it appears to be 2 tubes in one. This tube tests okay on my tube tester.
The schematic does not appear all that complicated, but obviously, at this moment, I'm over my head. Any clarification would be greatly appreciated, as would some direction, as to where to begin investigating. Many thanks, in advance.
