> I've had various verticals, trapped and non-trapped, for HF.
> Right now, I'm using the R8, which has been a good performer.
> (The new Yagis, which replace wind damaged units will go up
> this spring.) No, it will not give you the strongest signal
> on the band or beat out a good Yagi on a reasonable tower.
> (I think Cushcraft's gain figures are overly optimistic.)
> When the band is open, however, it performs credibly; I've
> worked DXCC on 30M and KL7 and KH6 on 6M. As Cushcraft
> states, it should be mounted at least 10 feet above the
> ground. However, much higher mounting will emphasize
> high-angle radiation.
The height is a compromise between ground induced losses on the
lower bands and elevation issues on the higher bands.
With an elevated vertical (ground plane) mounted 1/4 wave above
ground the peak gain is about 1.0 dBi at 16 degree t.o. angle.
As the height moves above 1/4 wave a higher angle lobe forms -
at 3/8 wave the high angle lobe is 0.3 dB at about 55 degrees
t.o. angle and the primary lobe is about 1.3 dB at 15 degrees.
There vertical pattern dips about 4 dB between the two lobes.
When the height reaches 1/2 have above ground the "high angle"
lobe is 1.8 dBi at 48 degrees ... the low angle lobe is around
1.0 dBi at 13 degrees.
As one goes above 1/2 wave a third lobe is formed but it remains
5 to 6 dB below the two lower angle lobes.
All this assumes that the support and feedline are properly
decoupled from the radials (or counterpoise) and do not radiate!
73,
... Joe, K4IK
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Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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