Congratulations
Seems like more and more some mica caps are hard to assume as being good.
Yup, the radios, their components,
and their caretakers are just getting older every day.
I've been replacing carbon resistors as a matter of course in a restoration for several years now. In recent years, I've started automatically replacing common value micas (100 pF, 250 pF) as well.
I think this problem will only get worse over time...
"Keep 'em Flying"
Nicely done! I've been watching this one b/c I noticed the same symptom on SW started cropping up on my 41-616 too. WWV (my alignment reference for all 3 SW bands) started coming in multiple times on approximately 1 MHZ steps and I easily re-created it with my signal generator. Could you let me know which ones specifically that you replaced so I can cross-reference? Thanks!
Recarb and Recap, I'vebeen trying to coin the first for a while, and I don't sell any or 'em.
All, Ok the Caps I replaced to make this work were.
All Mica..
Part # 27 185 uuf Replaced with a 180 uuf
Part # 23 185 uuf Replaced with a 180 uuf
Part # 20 250 uuf Replaced with a 270 uuf
Part # 29 185 uuf Replaced with a 180 uuf.
Not sure which one or a combo of them cured the alignment problem. Most of these have to do with either the OSC coil Part # 24 or the Osc tube 7C5.. See schematic for part # and location..
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Did you happen to have those on hand or did you order?
Curious since the time you started to investigate to the time you fixed it was only a few days.
If you ordered them and received them that quickly where did you order from?
I had them on hand. Normally you do not have to replace Mica Caps. But looks like these old radios some if not all of the caps drift. Do you have a capacitor meter? easier to check caps around your Osc tube then trying to replace all of them.. Mine were way out of spec..
Skip...
I do have a cap tester. Its old and don't recall what ranges it does. I'll check when I get home.
Found what I have online. I have the Simpson 383A.
Ok that should work good. Be careful as it has High voltage. Get hold of a manual in case you don't have one and learn how to use it.. If you don't already know..
Post what you find out
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