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Re: [TowerTalk] phasing multiband verticals

To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] phasing multiband verticals
From: "Dick Williams" <k8ztt@mho.com>
Date: Mon, 9 Mar 2009 20:32:09 -0600
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Jamie,

I have two Force 12 160 mtr verticals that I have spaced at 1/2 wave and am 
using the ComTek PVS-2 system.  It uses a three wire configuration to switch 
three directions.  Before I bought that, I was using a home brew phasing 
system that gave me either an end fire or cross fire pattern (feeding in 
phase or 180 out).  The nice thing about the ComTek is it uses a 2.25:1 UNUN 
for the in phase matching and an electric 90 degree phase shift to give gain 
for either direction of the end fire.

Actually the best spacing for their system on 40M is 49 ft (more than a 
quarter but less than a half).   I use 1/2 because that gives me better 
cross fire gain at the expense of some end fire gain; and my verticals are 
on a NW/SE line (NE/SW would be better, but that wouldn't work at my QTH).

I have mono band antennas for all the bands and only run one coax and two 
rotor cables into the shack.  I designed and built a remote switching system 
that uses +, -, 0, and AC down the coax along with a hard wire to the first 
relay box that I use the same voltages to swith the one coax out to the 
first four runs to additional switch boxes.  The only reason I have two 
rotor lines is I needed a seperate one for the Orion 2800.  All the other 
rotors are Hy-Gain and I remote switch them so I only have one CDE (Hy Gain) 
rotor box in the shack.

You might look into control voltage down the coax;  and if you run a single 
wire out to a coax switch box (like the Ameritron RCS-4) you can switch 16 
antennas with four additional boxes.   I have three of the RCS-4s along with 
a couple of MFJ-4712's to do all my switching.  I called them up and bought 
just the relay boxes, and then modified them as necessary to work as I 
needed them to.

I will say that I have been very pleased with the ComTek PVS-2 on 160M.

Good luck

Dick K8ZTT 

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