RE: Q-Dope


From: Nick Kennedy (
Date: Thu Aug 15 2002 - 20:34:58 CDT

You'll sometimes see arguments over whether to even use the stuff. I guess
it stabilizes the windings mechanically, against vibration and so on. I
think all coatings lower the Q of a toroid a bit, but Q-dope does it
minimally, hence the name.

There was a good newsgroup posting by Roy Lewallen on the subject of using
other types of goop, including RTV and hot glue, I think. He measured the
effects of the various coatings on Q. I think this posting was once stored
on the now lamented VE3BPO QRP homebrew page.

Here's a link to it:,+RTV&hl=en&lr=&ie=UTF-

If that doesn't work, it came from a Google groups search on Lewallen, Q
dope, RTV. Easy to find.

72--Nick, WA5BDU

BTW--when I tried dissolving packing peanuts in acetone, I came up with a
disgusting, slimy glop. I've since been told that not all such materials
are polystyrene. Maybe I'll melt my beer cooler or minnow bucket next.

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