Date: Wed, 1 Jun 2016 16:47:03 -0700
From: Bob K6UJ <k6uj@pacbell.net>
To: towertalk@contesting.com
Subject: Re: [TowerTalk] Fwd: Change in Frequency As Antenna Height
Rises
You guys are way above my head :-)
I had no idea the resonant freq goes up and down as the antenna travels
on its way up.
## it only goes up in freq, as height increases.
I thought it just went up on a steep curve till about 15 feet then
gradually after that.
## That’s exactly what happens. But beware, 20 ft above the ground doesn’t
mean 5 ft above a 15 ft high garage roof.
I can see why some head scratching as we pass thru the "decrease zone"
"what did I do now" hihi
## forget the ....’decrease zone’...it doesn’t decrease.
## and the simple full size dipole is not shifting 217 khz higher in
freq....that’s pure fantasy.
## ask anybody who has a motorized crankup, like the 89 ft or 106 ft
variety, how much the
resonant freq of a rotary dipole, full size, or loaded, or 2/3 el yagi (
this is all on 40m)
increases as tower is raised from min ...to max. Ditto with a 80m loaded
rotary dipole.
Jim VE7RF
73,
Bob
K6UJ
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