You can also make the vert longer than 1/4 WL and that will raise the R
but introduce Xl. Fortunately a series cap fixes the Xl. I believe
that higher natural R **may** offset a bit the effect of the ground loss
as the ground loss is a smaller % of the vertical element's R. Doubt I
worded that right - should not have attempted it on so little coffee
this early in the AM.
73/jeff/ac0c
alpha-charlie-zero-charlie
www.ac0c.com
On 8/30/20 11:34 AM, Dennis W0JX via TowerTalk wrote:
Jeff's (AC0C) comments are an excellent summary of the choices available for
radials on 160. My main point in posting was that you can install an effective
radial system for the low bands with radials that are shorter than 1/4
wavelength with little efficiency penalty and a possible improvement in
radiating pattern.
I should have mentioned that an effective choke balun at the feedpoint is
absolutely necessary to produce effective results. See K9YC's choke cookbook
for that information.
Lastly, depending upon angle of radials and other factors, the feedpoint
resistance will usually be less than 50 ohms and SWR greater than 1 to 1 at
resonance. This can be remedied by an adjustable shunt coil across the
feedpoint.
73 W0JX
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