[TowerTalk] HF beam antenna decision

[W3YY]

The antenna design provides a 22-ohm feedpoint and there is a 2:1 balun
built in to the driven element.

----- Original Message ----- 
From: "Peter Sundberg" <sm2cew at telia.com>
To: "Joe" <WD0M at centurytel.net>
Cc: <towertalk at contesting.com>
Sent: Saturday, April 17, 2004 5:20 AM
Subject: Re: [TowerTalk] HF beam antenna decision


> At 15:23 2004-04-16 , WD0M wrote:
> >On top of my US Tower TX-455 is a SteppIR 4 element - beyond the size
> >limitations you are facing, so may I suggest a 3 element SteppIR, which
> >covers 6 meters through 20 meters, all WARC bands, and presents a 1:1
> >SWR?  I'd recommend LMR400 or RH-213 also.
>
> Just curious, how is the matching done on the SteppIR so that it presents
> 1:1 SWR over the whole range. I understand the fundamental properties to
> set the length of the elements with stepper motors, but normally a yagi
has
> a lower impedance than 50 ohms at j0. Is the 1:1 shown on an SWR meter
> built up of a complex R + j or is the feed impedance really a pure 50 ohms
> resistive on all frequencies ?
>
> 73/Peter SM2CEW
>
>
>
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