Gentlemen:
Am finalizing plans using existing 60 ft tower with beam as short,
top-loaded 160m vertical. I need the tophat to exhibit approximately 50
elec. degrees to realize maximum current/gain from the tower. Due to only
being able to ground the 3 reflectors of the 9 insulated element beam, I
expect the beam to be good for only 30 degrees or so.
To make up the 20 degree deficit, I would like to add a tophat at 20 ft
above the beam. With careful design of the hat to avoid any HF band
resonance, the beam's performance should not be compromised.
According to some authorities, any "whip" added above a tophat will receive
minimal current. I am thinking the added capacity hat will function
normally however, adding its capacity to that of the beam's, for the total
of 50 elec. degrees. Plans are to isolate base of tophat pole from beam
mast & feed at that point, for higher impedance feedpoint. (also have remote
coax switch right there, allowing use of exist. feed)
Has anyone had any experience with dual tophats? I would sure like for this
setup to work, but can find no mention of such in any references I have.
Thanks in advance for any insight. Pls reply direct.
73, Doug / Nx4d
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