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Topband: two-wire beverage

To: "TopBand" <>
Subject: Topband: two-wire beverage
From: "Glen" <>
Date: Wed, 9 Sep 2009 09:48:51 -0400
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First post...

I am preparing for low-band season, after a poor 6M E season ;-(

I had two beverages fed at a common point with a relay switcher in the
woods, one NE and one

I have converted them to dual-wire ones, and they about 700' long each.

Here is the results from the on-line calculator:
Primary impedance 75 ohms
Zoa = 350 ohms
Zot 750 ohms
Zot turns ratio 2.15
Zoa turns ratio 3.17

So, I tried winding the transformers bifilar and that only yielded antennas
that worked only
in the forward direction, NE and NW.

Changed to actual center-tapped transformers and now it is working better,
but I am not sure it
is still right.

The main forward transformer I have is 3:1 turns ratio, with 3 turns primary
and 9 turns secondary, tapped at 4.5 turns.  From my feeble understanding,
this is to transform the 750
ohm feedline impedance to 75 ohm coax.  I know, not exact.

The reverse transformer 350ohm antenna to 75 ohm coax: 2 turns primary to 4
turns secondary.

The reflection transformer is 750 ohm feedline to 350 ohm antenna.  It has 3
turns primary,
center tapped at 1.5 turns and two turns secondary to ground rod.

Do you see a problem with this thinking?

Also, I have a control board in the shack with an AC power input that allows
me to switch
all 4 directions.


Glen K4KV
Moultrie, GA

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