Hi Mark,
I suspect the current -- and hence the radiation -- from the bottom of
the vertical radiator is somewhat suppressed by proximity to gull wing
radials.
When I first installed a 160 vertical using two gull-wing resonant
radials eight feet high I had to increase height of the vertical radiator
to achieve resonance at 1830 kHz. I had to shorten the radiator to
the classic length w hen I later replaced the gull wing radials with sixty
120 foot radials laid on the ground.
A little work in EZNEC would shed some light on this.
73
Frank
W3LPL
----- Original Message -----
From: "Mark K3MSB" <mark.k3msb@gmail.com>
To: "topBand List" <topband@contesting.com>
Sent: Thursday, July 25, 2019 5:04:33 PM
Subject: Topband: FCP vs Gull Wing Elevated Radials
This kind of goes with the other thread that has morphed into the FCP
topic, but is a bit different.
With an FCP feeding the INV-L, the bottom of the INV-L will be at least 10
feet off the ground. With my existing trees I can barely get up 50 feet
from the ground. So, the INV-L will have 40 feet of vertical radiator.
Using a pair of resonant gull winged radials feeding the INV-L at the
base, the vertical part will be 50 feet.
From what I’ve read, the FCP is a better solution over a pair of resonant
gull wing radials, but I’ve also read that vertical length of an INV-L is
important. So there’s a tradeoff to be considered.
Comments?
Due to real estate considerations, I can put up only 2 one-half wavelength
resonant radials
Mark K3MSB
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