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Old September 22nd 13, 06:41 PM posted to rec.radio.amateur.antenna
Irv Finkleman Irv Finkleman is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 220
Default Gamma Matching Question

Thanks to Jim and Jonesy -- I'm not very familiar with
all the ins and outs of Gamma matching, but in a number of
cases of Magnetic Loops where the loop covers a number
of bands e.g. 80-15m, 80-30M, the builders used a
Gamma match which when set needs no adjustment between
bands. Perhaps the Magnetic Loop has different properties,
although the authors of the articles claimed the matching
portion was a 'form of Gamma Match' and in one case
referred to the matching portion as a form of autotransformer
which I interpret to mean a non-circular feed loop of sorts.

In one loop design by Peter Parker VK3YE whose loop
covers 160-15 meters, the author advised me (when I
queried the Gamma question to him) that the
gamma when set as designed serves all bands well.
In other designs the gamma match or whatever it
might be, seems to work and did not seem to be a
problem or I think it might have been commented
on by the authors.

I will be investigating all these things soon -- I have just
recovered over a few years of some pretty heavy
abdominal surgeries and will be moving to a senior's
residence where I will have a balcony to work from.
It will be nice to get back on the air again after having
had to sell my house after the first surgery where I
had room for all different forms of antennas. Now I will
be back on the air again but will have to work under
certain restrictions such as no wires to nearby trees and
so forth. A magnetic loop or some form of windowsill
antenna will likely be my best bets. I'm looking forward to
the experience! I've always maintained to other old timers
who moved into condos where there restrictions that there
would always be some way to get on the air -- now I'm going
to have to walk the talk myself! One way or another I'm
not going to give up 55 years of hamming -- even if I can
only work across town! I'm shooting for multiband 80-10M
operation -- or bust! (Touch wood!)

Thanks,

Irv VE6BP
..
"Allodoxaphobia" wrote in message
t...
On Sat, 21 Sep 2013 11:50:40 -0600, Irv Finkleman wrote:
I am planning to build a magnetic loop antenna and
feed it by means of a gamma match.


I understand
that a gamma match will work over a wide range of
frequencies.


Your understanding is in error.
At best a gamma match will "work well" over a 1-2% freq. range --
for selected definitions of "work well.

Jonesy
--
Marvin L Jones | jonz | W3DHJ | linux
38.24N 104.55W | @ config.com | Jonesy | OS/2
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