Towertalk
[Top] [All Lists]

[TowerTalk] shunt feed

To: towertalk@contesting.com
Subject: [TowerTalk] shunt feed
From: Craig Clark <jcclark@wildblue.net>
Date: Tue, 15 Nov 2005 21:03:43 -0500
List-post: <mailto:towertalk@contesting.com>
>
>OK, with all this talk about shunt feeding - maybe I am ready to take the
>plunge.  I am usually not so stupid but I have read about shunt feeding and
>end up with more questions than answers.
>
>My tower is a 45G with an Optibeam OB17-4 on top (40 foot boom - 17
>elements) and then a WARC-7 (7 elements on a 14 foot boom) about 12 feet
>about the Optibeam.  So, quite a bit of top loading and with 80 foot tower I
>have wondered about shunt feeding for 80 and esp 160 meters.
>
>Can someone point me to a good step by step resource and will you also
>answer my questions afterwards?  I would love to do better on 160 meters.

How high is the tower? Do you have guy wires? Are they insulated from 
ground? If not, stop here and develop a plan B.

Put lots of radials down.

Run a wire or wire cage (6" - 12" on a side) to the top of the tower 
spaced 2-3 feet.  Ground this cage to the top of the tower.

Put a step-up L network at the base; you are matching 50 ohms to 
~~200 ohms (series L, C to ground on the antenna side.)

Tune for minimum SWR

You are good to go.

Craig K1QX
73, Craig Clark, K1QX

PLEASE NOTE NEW EMAIL ADDRESS
JCCLARK@WILDBLUE.NET

RADIOWARE AND RADIO BOOKSTORE
PO  BOX 209
RINDGE NH 03461
603 899 6957
WWW.RADIO-WARE.COM



_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>
  • [TowerTalk] shunt feed, Craig Clark <=