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Loop Question
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October 8th 04, 01:25 AM
Aaron
Posts: n/a
ospam (Theplanters95) wrote:
It looks like I could place a loop around the eaves of my house and it would,
in theory, be resonant around the 40m band.
I have such an antenna. It varies in height from 8' to 20' (at the roof peaks).
It is in an 'L' pattern (as is the house exterior). It is slightly more than
200' long and most is #22 wire (in the hidden areas), with a short run of #30
across the front porch area. My MFJ analyzer says it's resonant below the 80M
band.
I'm planning on either feeding it with ladder line with a very short run into the house.
I feed it with about a 20' length of ladder line.
or use a 4:1 balun
I originally tried feeding it direct using an unbalanced manual tuner but this
required manual tuning on all bands (a pain), and produced some RF in the shack.
(Not much, but enough to get into my cordless earphones and be annoying.) Using
a 4:1 balun not only solved the RF problem, but also made my TS870's auto tuner
happy on all bands except 80M.
How can I make the antenna also resonant on 75m?
I don't think you need to. Just hook up a tuner and play around. (BTW I got the
same signal reports with and without using the 4:1 balun, so if it doesn't solve
any problems for you as it did me, leave it out...)
I am planning on using it for 75m-10m.
I've made contacts on 80M thru 17M (so far) using this antenna, and get mostly
average reports, nothing spectacular, but nothing bad either...and I am on the
air. I have 2 Hamstick dipoles in the garage attic (about 9' up) for comparison.
The loop always beats the 40M Hamstick, usually by 2 S-units or more. The 20M
Hamstick beats the loop most of the time, but usually not by much. Apparently
the loop becomes less effective the higher it goes.
Perhaps with some experimentation I could improve things. However I am satisfied
and will leave it alone. I want 'double stealth', that is not only can neighbors
not see the antenna, but also that they don't even know that I'm a ham. I think
that will save me a lot of grief with this low close antenna...don't you...
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