That statement doesn't agree with my quick modeling (I also wondered why
my 40' base had some observed benefit on high bands now and then). Both
a 60' for 160 and 40' for 80/40 worked fine.
for a 60' baseline, 6' Z bottom wire, 30' Z to top or about 190' of wire:
Freq Gain dbi F/B db peak ang
1.8 -31 12 20
3.5 -16 15 25
7.0 -4 9 30
10 elliptical broadside about 5 to 10db F/S, 25 deg elev
>14 spikey pattern broadside and low vertical gain, maybe not useful
EZNEC 4.2 over average soil. With higher conductivity soil, F/B
improves a lot, and gain a few db. Patterns are about the same.
Grant KZ1W
On 6/30/2019 9:03 AM, Martin wrote:
Topbanders,
just read a few articles about DHDL antennas. One article states, the
cut off frequency where the antenna becomes useless is when the overall
length of wire reaches a 1/4WL. In my understanding the original
dimensions , 2*7.5m vertical plus 22m horizontal plus 2*13.3m sloping
wires equals 63meters, which is already a lot longer than 1/4WL on 160m.
What did i miss?
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