Resonance, in the normal sense has nothing to do with the value of impedance
only in a minimum (for a series tuned configuration) or maximum (parallel
tuned). While its possible to make the argument that a dummy load is a
resonant "antenna" with a Q of 1 (Q=Fr/BW or infinity/infinity) the concept
of a "resonant frequency" of infinity is counter intuitive. Since "dummy
loads" are made with real world components, we know that the "resonant
frequency" can not be infinity. So in that sense, the "dummy load" is a
very low, non unity Q "resonant circuit" but it fails in fitting a second
order differential equation for circuit analysis. If the shoe doesn't
fit...
That still doesn't negate the fact that radiation efficiency is the key to
propagating a signal.
BTW, I operate a fairly effective "dummy load" on HF... a B&W BWD-180
terminated folded dipole. It's pretty flat from 1.8 to 30 MHz. but its
efficiency is all over the place in that range.
It works but...
73 de Perry - K4PWO
----- Original Message -----
From: "Scott McClements" <kc2pih@gmail.com>
To: <towertalk@contesting.com>
Sent: Friday, August 07, 2009 10:57 AM
Subject: Re: [TowerTalk] Resonance is over rated
How do you define resonance? My dummyload on 80 meters shows an
impedance of 55 + j0 Ohms, it doesn't get anymore resonant than that.
-Scott, WU2X
On Fri, Aug 7, 2009 at 3:37 AM, Perry - K4PWO<k4pwo@comcast.net> wrote:
> The dummy load isn't resonant
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