Ron, K6UR asked:
"Should I care about front to back ratio if I aim one at the Caribbean?
There is nothing in the Pacific to cause me qrm so just wondering about
if I should have concern over f/b ratio's?"
The main purpose of a directional receiving antenna on 160m is to get
better S/N ratio on receive. The S/N will be better than a single
vertical simply because of directivity. Rejecting QRM from the reverse
direction is of little importance unless perhaps you have a noise source
you want to knock down.
I estimate that a properly fed Pennant or Flag will have the equivalent
S/N ratio as a 1-wavelength Beverage. This is based on my experience
with comparing Beverages (that I once had) with my phased verticals on
160m. 1-wavelength Beverages were about equal to the verticals'
unidirectional pattern on receive. 2-wavelength Beverages were a
magnitude or two better. In my estimation, 2-wavelength Beverages would
have about equal or slightly better S/N ratio on receive as a well-tuned
4-square array.
The pattern of a Flag or Pennant is only slightly better than my phased
verticals, so I don't expect to gain anything on receive (unless I put up
two Pennants widely spaced as a broadside receiving array). The reason I
put my switchable Pennants up is to prove the design works, hi. Read the
post I submitted to the Reflector a few minutes ago for test results so
far.
73, de Earl, K6SE
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