On 03/26/2010 10:43 PM, david park wrote:
> I have just borrowed an SWR meter and am trying to tune my Comm
> antenna. The manual says to tune by shortening until minimum reading at
> 127.50
Well, somewhat contrary to what others tell you, I wouldn't make a big
deal out of it. You just need to verify that the SWR is no higher than
2.5 anywhere in the frequency spectrum you intent to use. No need to
make a graph in my opinion, just dial through the band, transmit on
every 100kHz to verify that the SWR is acceptable.
HAM's usually strive to perfection, but you aren't going to moon-bounce,
DX, trying to reach the other end of the world with 1 milliwatt, or
working with satellites.
You have 10 Watts or so to spoil, have a very short cable in comparison
to HAM-stations, are transmitting from a height HAM's usually can only
dream upon, and without obstacles in your transmission path.
You won't notice any SWR improvement from 1:2.5 to 1:1, even with a
lossy cable. Just relax.
BTW, I'm a HAM myself.
The real challenge in airplanes is to keep the interference between
avionics and your signal as minimal as possible, so spend your time on
that, rather than chasing the perfect SWR.
Just my 2 cents.
Frans
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