As a contester, I do not disagree at all that every dB is worth
chasing however it does come at a great cost. I also concur about the
off center frequency gain difference being much greater using a full
sized OWA. The point of my towertalk post was that a shortened
antenna can be pretty efficient however the bandwidth is compromised.
I imagine that it is possible to have a reverse pattern on 40m if you
go too far off frequency.
John KK9A
Ed Sawyer N1UR wrote:
I think that there is not only the PEAK gain but also the gain over a
certain bandwidth. 48 ft boom OWA Yagis may only have a peak gain
difference of 2dB over the Optibeam 18 ft boom antennas. But if they are
graphed from 7000 - 7250 - I bet you see more of an advantage to the OWA
antennas.
Personally, I think 2dB of gain is worth chasing. We all do a lot of
"fighting it out" on 20 and 40M. Every dB is worth it on those bands in my
opinion.
If you have the Optibeams optimized for CW, you could be more like 3 - 4 dB
down from the OWA stack at 7200.
I have a 3 el M2 on a 36 ft boom. And a 42ft boom OWA yagi sitting on the
ground yelling to be put up. The M2 has nice bandwidth performance from
7000 - 7200 but it drops off rapidly above 7200.
Ed N1UR
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