01-16-2019, 10:55 PM
Thanks for your help mikethedruid. I'm glad I paid attention to your advice and revisited the bushings.
Now, I'm back to the FM problem. I received my new tubes today and they made no difference, so I'm back to troubleshooting. There are several symptoms, but rather than list them all and possibly cloudy the situation, I want to go back to these tests:
And here is the associated part of the schematic (I hope it's readable...if not I can post a larger pdf on my Google Drive):
When I preform step 2, I receive a significantly smaller output signal than I received at step 1. I looked at it on the scope and at step 1 I had 500mv peak-to-peak, at step 2 I had 150mv peak-to-peak. I believe I have Z301 tweaked up properly. I've had Z301 apart and cleaned the trimmers and replaced C301C (after the fact I figured out that this cap was only in the circuit in AM mode). Everything in the can looks good and the dc resistance of the coils look good. I've also replaced C308, C309, and C310.
So, can someone help me figure out why I'm losing signal through this can?
Thanks!
Rich
Now, I'm back to the FM problem. I received my new tubes today and they made no difference, so I'm back to troubleshooting. There are several symptoms, but rather than list them all and possibly cloudy the situation, I want to go back to these tests:
And here is the associated part of the schematic (I hope it's readable...if not I can post a larger pdf on my Google Drive):
When I preform step 2, I receive a significantly smaller output signal than I received at step 1. I looked at it on the scope and at step 1 I had 500mv peak-to-peak, at step 2 I had 150mv peak-to-peak. I believe I have Z301 tweaked up properly. I've had Z301 apart and cleaned the trimmers and replaced C301C (after the fact I figured out that this cap was only in the circuit in AM mode). Everything in the can looks good and the dc resistance of the coils look good. I've also replaced C308, C309, and C310.
So, can someone help me figure out why I'm losing signal through this can?
Thanks!
Rich