Topband
[Top] [All Lists]

TopBand: shunt-feeding towers and elevated radials

To: <topband@contesting.com>
Subject: TopBand: shunt-feeding towers and elevated radials
From: andrew@gi0nwg.demon.co.uk (Andrew Williamson)
Date: Mon, 23 Mar 1998 21:07:48 +0000
In message <19980322.184647.9623.11.km1h@juno.com>, km1h @ juno.com
<km1h@juno.com> writes
>
>On Sun, 22 Mar 1998 20:49:33 +0000 Andrew Williamson
><andrew@gi0nwg.demon.co.uk> writes:

>>At Robert GI0KOW's QTH at present is an Inverted-L running up the side
>>of a tower, spaced about 3-4 feet from the face of the tower.  It has
>>about 16 random length buried radials attached (50-250ft).  It works
>>after a fashion, but not as well as we'd like.  Especially not in
>>contests :-(
>
>He is plenty loud here at all times! Do you know the ground conductivity?

'Loud' maybe, but not loud enough Carl ;-)  I have no idea of the ground
conductivity.  It is heavy soil, I suppose half peat and half clay with
a solid rock base about three to four feet below the surface.  The
concrete base of the tower is actually about a foot into the rock.  It
wasn't fun digging THAT out, even with a mechanical digger!!

>The BW should be excellent at the 90 degree point but feeding could be a
>problem. I would be interested in the replies you receive for feed
>methods. With such a wide face I wonder if the standard Gamma/Omega match
>would work. The d1/d2 ratios with say a 1" diameter rod would be extreme.

I knew there would be a problem somewhere.  BW isn't a major issue,
provided it covers at least 1.81-1.87 which is where all the contesters
operate.  When you say the BW should be excellent, I'm assuming you mean
more than 60Khz.  If this is the case, I'd be more than happy to trade
some BW for an efficient, easy to match system, if such a thing exists
for this type of structure.

Thanks for your help.

Vy 73,

Andrew Williamson GI0NWG / AC6WI
Homepage = http://www.gi0nwg.demon.co.uk/

--
FAQ on WWW:               http://www.contesting.com/topband.html
Submissions:              topband@contesting.com
Administrative requests:  topband-REQUEST@contesting.com
Problems:                 owner-topband@contesting.com

<Prev in Thread] Current Thread [Next in Thread>