Stuart, I am forwarding you two postings from Roy about baluns. FYI . . .
In my testing I have found my bead baluns to cover 80-10 in fine shape with
"enough" balun action on 160 to be useful. Six beads extends coverage to 160
but then ten meters starts to show unwanted reactive effects.
73/72, George
Amateur Radio W5YR - the Yellow Rose of Texas
Fairview, TX 30 mi NE of Dallas in Collin county EM13QE
"In the 57th year and it just keeps getting better!"
<mailto:w5yr@att.net>
----- Original Message -----
From: "Stuart Rohre" <rohre@arlut.utexas.edu>
To: <tentec@contesting.com>
Sent: Friday, July 11, 2003 1:07 PM
Subject: Re: [TenTec] Balanced Tuners
> Interesting George about Roy and the solenoid choke.
>
> The only thing I had read on his web site recently was his retraction of
> saying the input BALUN was superior to an output side balun. His most
> recent analysis of that shows the effects on the balun are the same.
(Which
> is puzzling since clearly the voltage in a 50 ohm system are not the same
at
> higher impedances seen on output, but that is another rabbit hole).
>
> I tend to agree with you, (at least I think your implicit point) that
cores
> on a coax length are an entirely adequate, economical and wide band
solution
> to blocking outside the shield reverse RF current, ie act as a balancing
> device by prevention of incidental reflections.
>
> The core choking action is more flat in frequency response than a coax
> solenoid which still has distributed discrete Capacitance and linear
> inductance due to the center wire.
> The distributed capacitance term goes away with the shorter core solution
> upon the outer shield.
>
> Is that what you were thinking?
> Somehow, I think most coax cable chokes are used in either triband or
single
> band applications, where frequency response might be acceptable.
> :-)
> 73
> Stuart
> K5KVH
>
>
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