[TowerTalk] Resonance is over rated

[Dave - AB7E]

If I match at the antenna and choose proper components for the matching network, the amount of power actually transferred to the antenna is more a function of what the real part of its feedpoint impedance is than what it's reactance is (i.e., how far off resonance it is).  If I match at the rig, then yes, I have to contend with the additional feedline losses and that will be a function of the SWR and line length.  In either case, computer programs like TLW (free with the ARRL Antenna Book) will calculate both the network parameters and the losses (feedline and component) for you so that you can make an intelligent decision.  Try a few examples ... I'll bet you find that resonance isn't as important as you think.

Dave   AB7E


------Original Mail------
From: "bill rubin" <brubin2010 at gmail.com>
To: "Dave - AB7E" <xdavid at cis-broadband.com>,
    "Towertalk e-Goups" <towertalk at contesting.com>,
    <k6xyz at sbcglobal.net>
Sent: Fri, 7 Aug 2009 01:50:23 -0500
Subject: Re: [TowerTalk] Resonance is over rated

True... but the comment is that was resonance was overrated. I disagree.
Sure an transmitter can be "happy" with seeing proper impedance (like with
antenna tunner) but how much power is getting to that antenna ?  How much is
lost is the cable ?  thats my point.


On Fri, Aug 7, 2009 at 1:20 AM, Dave - AB7E <xdavid at cis-broadband.com>wrote:

>
> That's a fairly ambiguous statement from K4IPV and I think you are possibly
> misinterpreting it.  I can put a properly designed L-network at the base of
> a 50 foot high 80m vertical and it will do exactly what K4IPV recommends.
>  It has nothing to do with whether the antenna is inherently resonant or
> not.
>
> 73,
> Dave   AB7E
>
>
>
> ------Original Mail------
> From: "bill rubin" <brubin2010 at gmail.com>
> To: "Dave Harmon" <k6xyz at sbcglobal.net>,
>    <towertalk at contesting.com>
> Sent: Thu, 6 Aug 2009 23:44:16 -0500
> Subject: Re: [TowerTalk] Resonance is over rated
>
> per the book Antenna Toolkit by Joseph J. Carr, K4IPV
>
> "The only really proper way to reduce the VSWR to 1:1 is to tune the
> antenna to resonance and then match the impedance."
>
>
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