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Old November 24th 08, 09:56 PM posted to rec.radio.amateur.antenna
Michael Coslo Michael Coslo is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 828
Default Loop efficiency, was multi-turn magnetic loops

Steve wrote:

Yes, I know there's nothing to gain in terms of performance. However,
I have very little space to work with. I have a 1 meter diameter loop
installed in my (tiny) attic that works very respectably on 10-30
meters. It won't get me onto 40 meters, though, and getting onto 40 is
either going to require a much larger diameter single-turn loop, a two-
turn loop, or a much more robust capacitor. Trying out a two-turn loop
seems like it would be the easiest and least expensive alternative,
and I already have the copper tubing I would need.



I separated this out from the noise floor......


When I was dealing with a loop, I wanted to extend the frequency
downwards - it's a pretty big loop, but trying to hit 75 meters was a
goal, I had some exchanges with Reg, and he pretty much told me to put a
extra capacitor across the terminals so I could tune it to the lower
frequency. That was a smack the forehead moment for me.

And Oh yes, tuning will be sooooooo tight. But the cap will probably be
better than an extra loop. You'll just have to figure out how to switch
it in and out of the circuit.

- 73 de Mike N3LI -