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Message-ID: <004101c6a1f8$a97ada80$16c428c3@captbrian>
From: "captbrian" <captbrian@ukonline.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <004b01c6a1ec$92156fb0$6501a8c0@eagles>
Date: Fri, 7 Jul 2006 20:07:08 +0100
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Subject: LF: Re: Antenna Tuning
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suggestions :

Just ease away on the halyard so vertical sags away from the tower. ..to
decouple further.

Lower the top of the coax to the ground and check for dc continuity from
braid at bottom to braid at the top. and also to the top sections.

Remove the  coax  and use a plain wire vertical.

Make both top sections the same length.

Disconnect one top section for now and have a plain old fashioned inverted L

Measure the resonant HF frequency of the antenna without bottom loading.
That may reveal some discontinuity in the system.

For test purposes  : screw the ' local electrical code.'

Any hams in the area who would come round to check your set-up?

Where are you sampling the volts and amps that you expect to see
out-of-phase ?

Bryan


----- Original Message -----
From: "J. Allen" <vy1ja@northwestel.net>
To: "LF (RSGB)" <rsgb_lf_group@blacksheep.org>
Sent: 07 July 2006 18:41
Subject: LF: Antenna Tuning


> Mike and All,
>
> The reason the tower has been bonded to ground is that the tower supports
HF
> antennas as well.  The feed lines, rotor cable, and remote antenna relay
> control cable would need to be decoupled at LF which I am unfamiliar with
> accomplishing.  My attempt to decouple was to put the feedline out at 4
feet
> from the tower.  I do not want to get too far from the tower, because my
> ground system is tied to two 10 foot ground rods at the tower base.  These
> ground rods are required by local electrical code for grounding the tower.
> If I unground the tower for LF, I have to find a way to connect the rods
but
> have them decoupled at LF.
>
> Yesterday, to make sure that the HF wire antennas were not part of the
> problem, I took them all down.  The only antenna left on the tower is a
> small A4 tribander.  When this was done, it made no difference at all on
the
> LF tuning.
>
> Does anyone know how far out from the tower will be the best distance for
a
> 100 foot vertical riser of 1/2 inch coaxial cable?  Would I be better off
by
> making the vertical riser a single #11 wire instead of the coaxial cable?
>
> Mike, you said that this may not be the problem at all, because you had
done
> a similar installation without these problems.  What is different about
your
> installation?
>
> Anyone who has been following, please brainstorm and think of any
> possibility which I should be looking for.  Because I get confused, I
could
> have made just about any kind of mistake imaginable in the construction of
> the antenna, but whatever it is, that antenna sure works on receive!
>
> I will be leaving for Edmonton for neuropsychological testing related to
> early Alzheimer's on July 9 and will be back on July 12.  Please think
about
> the antenna problems.  I hope that someone can find the little fox in my
> antenna vineyard.
>
> J.
>
>
>
>
>
>
>
> --
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>