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Old July 12th 04, 06:16 PM
Jerry Martes
 
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"Malcolm Austin" wrote in message
...
Hi,
I have an interesting problem which I'd like to put to the

newsgroup
for idea's. Our club (gliding by the way) uses just a few frequencies to
transmit (AM) and receive on.

The main freq' is 129.975, but we go down to 129.900 and up to 130.400.

We need some new antenna's but I'm wondering what would be the best.
Currently we use a quarter wave set for 129.975, but this is I'm afraid

just
cut to a length (the lads are pilot's and not Ham's !!)

The quarter wave of course is good in one respect that we are all

hopefully
up in the air so the high angle of radiation helps. It would be good

though
to improve the signal to our winch which is just 950 metres away (3100

feet
for some!) but over the hill so to speak, so not line of sight. We

struggle
at times on our max 1 watt output to hear each other.

I'm wondering what I can build that will help this low angle but leave the
high angle still there. Also it would help, to have the VSWR band width
with us and not against us on all the frequencies. For the winch we have
limited height available on the top due to hangerage restrictions. If I
build something big and solid, some one is sure to forget and rip it off
going into the MT hanger. Our base end is a good old English double

decker
bus, so we have a good ali ground plane some 20 feet in the air. None
directional capabilities are of course required as we fly 360 degrees

around
the club.
Any thoughts out there?

Many thanks,

Malcolm - Radio Ham and Glider pilot.


Malcom

I'd suggest that the antenna at the winch can be made more directional
without increasing its height. But, you've probably thought of that. It
would seem to be a good place to try a simple, small Yagi at the winch.

Jerry