>
>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.
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