[TowerTalk] Dipole Problem

[Mike Brown]

You'll get that kind of reading if the ends are too close
together. If your antenna is U shaped, or V shaped,
then that is the problem. Antennas that zig and zag
around should have a low swr, as long as the ends
are as far apart as you can get them. I have a 160m
dipole on a 50x130 lot that does a lot of zigging and
zagging around off my 40ft tower. Keeping the ends
at opposite ends of the lot, I have a 1:1 at around
1850.

This isn't an ideal situation, but a 2.3:1 SWR on 75m
should be easy to match with an auto tuner, or manual
tuner.

The correct way to put up a dipole (if you can) is to
keep it in a fairly straight line. But, if what you are
doing is the best you can, use a tuner to keep the rig
happy and have fun!

73, Mike K9MI




----- Original Message ----- 
From: <K6TFZ at aol.com>
To: <towertalk at contesting.com>
Sent: Wednesday, February 18, 2004 22:17 PM
Subject: [TowerTalk] Dipole Problem


> I always thought a dipole was simple. First the description:
>
> 75 meter dipole (58.5 feet per leg) placed 4 feet above peak
of second story
> roof. Roof is 40 feet wide so ran extra wire at right angle
outward toward
> rest of house (big square "U").
> Center of dipole is in center of 40 foot section using a large
egg insulator
> and an SO-239
> to start, balun later.
>
> My AEA-HF and Autek RF-1 both read resonance at 3968 KHz which
is fine BUT
> SWR is about 2.3:1, R=29 ohms.
>
> The only thing I can figure is the way I wrapped the wire on
the egg
> insulator: so that if
> the insulator were to break, the wires would catch each other
and not part.
>
> Could there be that much capacitance there to throw my reading
off that much?
> The wires are at right angles to each other. Any other
suggestions?
>
> TIA.  Geoff, K6TFZ
> _______________________________________________
>
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