Thread: Coil Dope
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Old February 9th 09, 07:51 PM posted to rec.radio.amateur.antenna
Dave Platt Dave Platt is offline
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First recorded activity by RadioBanter: Jul 2006
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Default Coil Dope

I read that old 78 LP's broken into pieces & mixed with a particular solvent
was used as coil dope. Does anybody remember which solvent was used & how
affective it was?


78s were often made of shellac, and the usual solvent for shellac is
denatured alcohol. I believe that some other 78s were made from
cellulose acetate... for this material I believe that acetone would be
a usable solvent.

My understanding is that commercial Q-dope uses polystyrene, dissolved
in a suitable solvent.

According to an article by Barry Ornitz WA4VQZ (the text is at
http://yarchive.net/electr/coil_dope.html), a very acceptable coil
dope can be home-brewed by dissolving ordinary polystyrene "packing
peanuts" in either toluene or acetone (the latter is less toxic).

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Dave Platt AE6EO
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