09-30-2012, 11:11 PM
I'm having trouble aligning the IF stages of a 1935/36 116B-121 Tombstone, (2nd Detector, 2nd IF, 1st IF). It's been recapped and out of spec resistors replaced, but I'm not getting much deflection on the shadow meter and the AVC voltage is about half what it should be.
What I noticed while doing the alignment is that the tuning slugs want to be turned all the way down for maximum output voltage. And even bottomed out I don't pass through a peak voltage point.
I have not replaced any mica caps, but the only ones I see in the IF stages are the variable mica caps to trim the coils. Resistance in the coils checks out.
I've tried removing the 3 IF cans to have a look, but haven't figured out how to do it. They look to be spot welded together and must come out as a unit. Would appreciate any tips on freeing all three retaining clips.
Any ideas on what to try next would be very much appreciated.
John
What I noticed while doing the alignment is that the tuning slugs want to be turned all the way down for maximum output voltage. And even bottomed out I don't pass through a peak voltage point.
I have not replaced any mica caps, but the only ones I see in the IF stages are the variable mica caps to trim the coils. Resistance in the coils checks out.
I've tried removing the 3 IF cans to have a look, but haven't figured out how to do it. They look to be spot welded together and must come out as a unit. Would appreciate any tips on freeing all three retaining clips.
Any ideas on what to try next would be very much appreciated.
John
