Posts: 7
Threads: 2
Joined: Nov 2014
City: Baltimore MD
(03-13-2015, 11:52 AM)Mondial Wrote: Brockrak, whoever you decide to use to restore your radio, make sure they use polyester or polypropylene film capacitors for the power supply filters.
Many so called restorers will try to use tiny modern electrolyic capacitors for the original low capacitance paper filter caps. Todays 1 and 2 microfarad electrolytics caps were not designed to withstand the high ripple currents they would be subjected to in this service and will fail in a short time. Film caps on the other hand are designed for such conditions and will last almost indefinitely.
In fact, in discussing restoration of your 87 with prospective restorers, mention the original paper filter caps and what they plan to replace them with. If they say electrolytic caps and do not understand the potential problems, look elsewhere!
Thank you all for your wealth of knowledge
Posts: 7,215
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Joined: Dec 2009
City: Roslyn Pa
Mondial is correct as always. I put some electrolytics in my 87 and it worked fine for about 6 months. The input cap shorted and it started to eat the 80 tube. They get a nasty angry red glow in the plates. Then poof goes the 80 or the 80 and the power transformer. The e caps where cheaper but not in the long run.
Terry
Posts: 65
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Joined: Feb 2014
City: Clayton, NC
Where are you located? If we knew that, maybe someone could point you to a local forum member or repair person.
Have you checked for any antique radio or wireless clubs in your area? Or even a ham radio club? A lot of those guys also work on old electronics.
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City: Bandon
State, Province, Country: OR
Brockkrak is in Baltimore and I pointed him to MAARC as a possible local resource in an earlier post but there may be other mid-Atlantic folks who could help him.
