Topband: Shunt Feed wire

[Harold Smith]

Jorge:

An easy way to do this is to use an Omega Match.

I have been using this on my 25 meter tower with a 5 el 20 meter Telrex yagi
on top for about 15 years.

My tap is 12 meters high and spaced out about 1 meter. It is made from 18mm
tubing and I use a 500pf vacuum variable for the omega capacitor and also
one for the gamma capacitor. If you run over a few hundred watts don't use
air variables

The vswr is 1:1 at 1833 kHz. The 2:1 band width is about 30kHz. If I made
the matching rod longer then the bandwidth would be a bit wider, but it
works fine for me as is.

It works very very good !!

73 and good luck

Price WØRI and club station WØCKC (St. Louis Low Banders Club}



----- Original Message ----- 
From: "EA2LU Jorge Daglio" <ea2lu at telefonica.net>
To: <topband at contesting.com>
Sent: Friday, August 27, 2004 8:29 AM
Subject: Topband: Shunt Feed wire


> Hi all, Is time to improve the 160m antennas, then I check my shunt feed
tower with
> the RX noise bridge and found it is up on frecuency (TAP is near the
middle).
> I think will be better to go up with the tap point , to start I will put
it on the top
> (near 27m high) and then down it if necessary.
> But the trhouble is I have not wire enough (10mm diameter) to go there,
then
> my question is: ¿Could I use RG-213 with braid and center togheter for
this purposse?
> I remenber somebody use it but not sure, and ON4UN mention that wire
diameter
> has little influence only in the bandwidth.
> Any opinion, would be greatly aprecciate.
> Thanks you in advance.
> 73 de Jorge EA2LU
>
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