Message-ID: <DA20579ADCFC43C69A7DD6E2771394C5@AGB>
From: "Graham" <g8fzk@g8fzk.fsnet.co.uk>
To: <rsgb_lf_group@blacksheep.org>
References: <1MTixd-0cGXyK0@fwd00.t-online.de>  <4A687388.4050801@usa.net>  <D4AD27687AE04388BC1A8867F5C27617@JimPC> <1MU4lz-1dRfeq0@fwd10.t-online.de> <434E6E4F7AC64D8B995F684D832555DA@JimPC> <49FC75F6A7D2439197581F10016D72AE@AGB> <000201ca0bfb$db158d40$0b01a8c0@weazle>
In-Reply-To: <000201ca0bfb$db158d40$0b01a8c0@weazle>
Date: Fri, 24 Jul 2009 13:48:35 +0100
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Subject: Re: LF: Loop discussion
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Ok JB

The loop is a equilateral  triangle 'flat', running about 90 feet above the 
sea level , each side is 200 feet , with the feed at the  apex of the 
 south - east side, opposite is the 'base' running approx , north east 
/south west. Total cable length just over 600 feet , 35 amp insulated mains 
cable was used, as we had a roll and it keeps the  salt spray off the  wire

The voltage build up seems to be  more of a problem with the  loop, not  sue 
as to the  final pd , but it gives a good flash and already has sent one 
chap across  the  room .and that was on a fine sunny day ... the  wire to 
the  light house, 680 feet, is still in place .. amazingly ... doesn't  seem 
to  have the  same static build up problem .. still charges but  no where 
near as much

The main use of the  loop to  date has been tx/rx on the  HF ham bands fed 
from a balanced tuner  and rx on 500, with one end grounded and the  other 
direct to the rx ... this produces quite a high level of noise, next is to 
try a small tuner with  loop coupling to float the  array . We have not  yet 
transmitted on the  loop at 500 but the  rx tuner should handle the  50 
watts so we can take a signal reading at  G4WGT grabber. The marine tx is 
looking for  a very  low Z feed so  any Ae coupling tends to  be step up , 
the  long wire is tuned with a parallel tuner , sort of  160 mtr fashion.

We did initially try a conventional  loaded vertical system, however as the 
Fort is 1000's of tons of sandstone rock it was difficult to tune the 
system with 'no' earth as such , the  loop was installed to  take its place, 
then we found that the  lighthouse was owned by the  owner of the  fort 
...one of those 'oh that's handy  moments' 
http://uk500khz.googlegroups.com/web/gb4f.jpg

73 - G ..




--------------------------------------------------
From: "J. B. Weazle McCreath" <weazle@hurontel.on.ca>
Sent: Friday, July 24, 2009 2:12 AM
To: <rsgb_lf_group@blacksheep.org>
Subject: Re: LF: Loop discussion

>
> Hi Graham,
>
> Would you kindly pass along some details of the GB4FPR delta loop?
> I've been using one here with a perimeter of 333 feet for several years
> now for receiving purposes in the range 160 to 530 kHz.  A binocular
> core with a 1:2 turns ratio at one of the bottom corners provides the
> step-up to the RG-6U coax to the receiver.  I've no problems with
> static charges or arcs (so far), but I have thought of putting some
> high value resistors from the loop ends to ground.
>
> 73, J.B., VE3EAR - VE3WZL
> Solar and wind powered
> Lowfer " EAR"  188.830
> EN93dr
>
> http://www.hurontel.on.ca/~weazle
>
>
>
>



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