Re: 1:1 Choke Location on Beam Installation
Jef - N5JEF
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The choke really should be at the antenna feed point. It is intended to present a relatively high impedance at that point, and minimize common mode radiation from the feedline.
What's your highest band on that beam?
As you know, a quarter wave transmission line transforms an open circuit to a short, and vice versa.
So, at 10 meters your 6 feet of coax (remember also consider the velocity factor) will be roughly a quarter wave and your choke will have roughly the opposite of its intended effect. At 20 meters, roughly 1/8 wave, so the transformation, as seen at the feed point, will be somewhere in between, and certainly not the high impedance as designed.
That said, ham radio xperience tells us that antenna theory is all magic anyway, and you'll still make contacts proving it works great.
So FWIW, have fun.
On Wed, Feb 19, 2020, 16:57 Dennis - WU6X <wu6x@...> wrote: