[TowerTalk] Towers and Open Wire Feeders

Rick Karlquist richard at karlquist.com
Fri Feb 2 14:44:34 EST 2007

There is a 50 ohm to 50 ohm balun on one #43 2.4 inch toroid
and a 50 ohm balanced to 450 ohm balanced transformer in cascade
with this on three stacked #61 2.4 inch toroids.  Works at
the legal limit.  The balun is wound with RG58 and the transformer
is wound with 150 ohm balanced line.

Rick N6RK

Jim Lux wrote:
> At 09:47 AM 2/2/2007, Richard (Rick) Karlquist wrote:
>>We use 50 ohm unbalanced to 450 ohm balanced transformers
>>at the ends of our 450 ohm open wire line (about 250 meters long).
>>Then the radio and antenna use short lengths of standard 50 ohm coax.
>>We run the system at a low SWR.
> What do you use for transformers?  (i.e. core material and size) at
> what power level?
> (I just got a copy of Soft Ferrites by E.C. Snelling (supposedly the
> ultimate reference on the subject) from the library at work. It's
> pretty heavy going, and it's nice to have some actual examples to
> work through... might as well be useful ones...)
> Jim, W6RMK

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