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My Model 60B came with both B+ electrolytic filter capacitors valued at 4.0 uF @ 600VDC (Aerovox 610M, big aluminum cans, at over five inches long and inch and a half diameter). All the schematics I've seen indicate they should be 8.0uF (Pt.No.7558). May I replace these with a multi-sectional can rated at 10/10uF, or if I can't find that, something like 16/16uF or 20/20uf since capacitors at these rating are easier to find. Or must I avoid a multi-sectional and use only individual capacitors? Radio has an annoying 60cycle hum.
Many thanks.
MD.
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Why not disconnect the two large filter cap cans but leave them in place for appearance. Then wire in two separate 10 uF electrolytics under the chassis.
You could use a multi-section can, but they are hard to find these days, and a modern one would be much smaller than the original mounting clamps so mounting would be a problem.
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A capacitor is a capacitor....use whatever you can fit and what satisfies the capacitance / voltage requirements.
Personally I prefer also satisfy a very crude rule of a thumb (I use it for myself) that the ripple current should be at least equal to the load current and the working temp should be 105C.
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You can restuff the electrolytic cap cans so you retain the look of the radio on both the top and the underside of the chassis. See this thread for some discussion on it (there are more threads on the topic as well if you do a bit of googling).
http://philcoradio.com/phorum/showthread.php?tid=6736
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I always restuff the electrolytics. But, to be honest, I hate the procedure.
It's like raking leaves in the fall or mowing the grass - I hate both. Still do it.
Keep in mind that those Aerovox 610Ms are NOT electrolytics, they are paper/oil caps and rarely fail.
However, the word "Hyvol" under the Aerovox name on the label is their name for PCB oil. If you clean these out to re-stuff them make sure you wear gloves and be careful. What you get out of the can is hazardous waste!
I just salvaged 5 of these out of the ruins of the Black Hole in Las Alamos last weekend.
Greg
N0WEK
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Welcome to the Phorum Greg and thanks for the heads up on Hyvol as a trade name for PCBs! In case anyone's interested here's a list of other PCB related trade names:
http://www.epa.gov/epawaste/hazard/tsd/p...tradenames
On the "truth is stranger than fiction side", Hyvol is now a trade name for
shortening and margarine products:
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So...you open the can, you get sprayed, you glow in the dark. Makes it easier to work without a flashlight.
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It originally used two individual caps and those are a lot easier to find and cheaper than a dual cap. I wouldn't bother trying the restuff those Aerovox. They're not original and there's the PCB hazard.
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The 60 is supposed to use two 8 uf 450 filter caps, I thing they may have been wet electrolytics originally. If you can't find a pair of 8 mf caps, use 10 mf caps, or 16's, or 22's, 4 uf is too low.
Regards
Arran