[TowerTalk] Phasing Muli-Band Verticals
Terry Conboy
n6ry at arrl.net
Fri Oct 19 14:01:13 EDT 2007
At 06:02 PM 2007-10-16, Mike K6QD wrote:
>I want to phase two HF-9V multi-band verticals and operate on all
>bands (80-10) that these antennas cover. I am severely limited by
>HOA restrictions and the antennas would be hidden when spaced ~130'.
>They would be mounted 15' off the ground with sloping radials. I
>have read everything I can find on this subject and most of the
>literature addresses only 1/4 & 1/2-wave spacing. The Hy-Gain
>report is interesting but it is also focused on the shorter ~66'
>spacing. I have used a single HF-9V for years with "typical"
>success. Any help with this issue will be appreciated. Tks es 73, Mike
With your 130' spacing (half-wavelength on 80m), as you have seen,
you can get nice bi-directional patterns (broadside and endfire) with
0 or 180 degree phasing.
On the higher bands, you will get multiple lobes of roughly equal
gain: four lobes on 40m, eight on 20m, twelve on 15m, and sixteen on
10m. The gain in the lobes will average around 3 dB (less ground
system losses). You can steer the lobes, and the nulls between them,
by varying the phase angle between the two verticals. Some sort of
tapped delay line scheme with the steps equal to 0, +/-90 and 180
degrees on each band could be useful on RX, but matching on TX could
be irritating.
Or you can buy a K3 with the optional second receiver and use the two
antennas for binaural diversity reception.
I can supply you some patterns for 40m & up if you like. I feel
your HOA pain, too. :(
73, Terry N6RY
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