Date: Sun, 3 Jul 2016 11:23:10 -0700
From: "Richard (Rick) Karlquist" <richard@karlquist.com>
To: Steve Hunt <steve@karinya.net>, Reflector -tower
<towertalk@contesting.com>
Subject: Re: [TowerTalk] Fair rite materials for choke baluns
On 7/3/2016 10:05 AM, Steve Hunt wrote:
> Rudy,
> http://www.karinya.net/g3txq/temp/52_mix.png
>
> It achieves Rs>5000 Ohms from 10Mhz thru 28MHz, and Rs>8000 Ohms from
> 12MHz thru 21MHz.
>
> Steve G3TXQ
>
It is more useful to think about Rp than Rs. Rp determines the
power dissipation for a given voltage. Although Z is a figure
of merit for how well the antenna works, Rp is a figure of merit
for how much power can be handled. On the G3TXQ curves, note
that where Z=Rs, it is also true that Z=Rp. Away from that
frequency, the general trend is that Rp monotonically increases
with frequency, at least up to resonance.
It's nice to brag about extremely high Z values, but even if
Z=infinity, all you have accomplished is that you have
disconnected the feedline from the antenna. It doesn't
guarantee there will be no feedline currents. Also, it merely
PERMITS the antenna to be balanced, if there is no external
conductor otherwise perturbing it. It does not guarantee
balance.
Rick N6RK
## Ok, Im lost. I thought we wanted Z > RS > XS .
Put another way, RS ideally should be the same as Z... or as close as
you can get to Z. And RS should definitely be > than XS.
What is RP ??
Jim VE7RF
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