Discussion in 'General Technical Questions and Answers' started by CAMERART, Oct 13, 2019.
No I simply forgot which way it works.
I think it goes out of match in different location situations, I'll see what happens.
I am a little bit late to this thread, but I have just found a snippet of information which may be relevant.
While reading something about Q measurements by W7ZOI, I noticed that he made some comments about a polyvaricon capacitor which he tested as part of his investigations into the Q of various capacitors and inductors.
The document by W7ZOI is here:
The interesting part is on page 19 of the document where he says:
With that in mind, it could be that the polyvaricon tuning capacitors from transistor radios are a very poor choice for use in a simple ATU, even one which is only ised for low power (<5Watts).
As a side note, my thanks to VK2TIL in this thread:
for bringing the Q measurements document to my notice.
Good going !!! Even if it is me, once in a while.
Cushcraft used to make the Skywalker monoband antennas. They used a series capacitor with a thick dielectric. The plates were about a foot long. In effect, it looks much like RG-8 with a solid sleeve. I suspect the reason they were discontinued was that it could not take the power. At least over a long period. You can get a manual on the Cushcraft Help Desk.
Thanks for the links.
I have looked at all this for years, and it doesn't get remembered unless, I try it live, by experiment. I'll have a 'play' soon.
I've added the little metal plate cap into the box, and I hope to test it.
"A foot long"! I won't really fit in the 2inch box I have, but thanks.