[TowerTalk] Which Balun with the TH7DXX

[Peter Voelpel]

Yes, I am pretty confident that it works on 20m.
30µH give me 2638 ohms.
On the feed line I measure no common mode current either.
I am using such on a 20m KLM yagi now which I converted to OWA two weeks
ago.
I use the same kind of choke on my 7 element 10m OWA but with 20 windings on
a 4" pipe.

It will be used on a new 6 element 15m OWA which I am just working on.

And next year I will convert 4 more KLM yagis and use this kind of balun
with them.

All coax cables are earthed to the boom after leaving the chokes and to the
top of the tower, half way up and at the bottom of the tower.

The tower is fed as a vertical on 160m and so far no problem with arcing or
band to band interference.

73
Peter

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Jim
Thomson
Sent: Dienstag, 23. Juli 2013 15:32
To: towertalk at contesting.com
Subject: [TowerTalk] Which Balun with the TH7DXX

Date: Tue, 23 Jul 2013 00:54:40 +0200
From: "Peter Voelpel" <dj7ww at t-online.de>
To: <towertalk at contesting.com>
Subject: Re: [TowerTalk] Which Balun with the TH7DXX

A solenoid winding made of coax is more effective then those 4 wraps.
I use SCF12-50 Cellfex to wind my choke baluns.
30 turns on a pvc tube of 4-5" diameter do the trick (2000 ohms at 14MHz).

73
Peter

##  are u sure  30 turns of 1/2 inch heliax is gonna work on 20 M ?   That
seems
like one helluva lot of turns for 20m.   Is it optimized for 20 M ?   How do
you know
its  2 k ohm Z ? 

Jim   VE7RF

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