Dave,
I can comment on the Cushcraft and M2 40 meter yagis, but have no experience
with the optibeam.
I live on the northern coast, next to Lake Erie. We get really nasty wx!
Wind, snow and lots of ice. So putting up an antenna for longevity was my
primary goal. I had a cushcraft that lasted maybe 1/2 of its first storm
then was shredded. Later I found out that it was designed "by feel" and
needed alot of work to strengthen. I gave it away.
I did alot of research. Decided that a 3el linear loaded was my best bet,
but knew that I didn't have the time to build it myself or engineer all the
linear loading. So I went with the 40M3L-125. It's the "survivor series"
linear loaded 40m yagi by M2. It did very very well in my wx and had no
mechanical issues whatsoever. Way up high it looks like a big 20m yagi. I
did take it down and replace it with a full sized 40M3FS-125 about two years
later. The 40M3FS-125 has had one mechanical failure, which I have elected
not to fix, yet (because I would have to hire a crane...so I am waiting
until something else fails before calling my crane guy): But when I do fix
it I will apply the re-design I devise to both my both my stored 40M3L-125
and my erected 40MFS3-125.
Both antennas have the "tip" section as 3/8 inch tubular aluminum. That 3/8
inch tip is too small for bad wx. The failure I experienced is that one of
the reflectors tips sheared off from either ice loading or vibration
failure. By upgrading the 3/8 to 1/2 inch it will have much better ice
loading survivability.
So I am planning to redesign using a 1/2inch diameter tip. It should be a
simple matter on either antenna, but will require some scaling due to the
effect of tubing diameter on resonance.
I am so pleased with the M2 antennas that I have over 12 of them! Wyatt and
the crew are very responsive. But they are busy, so plan about 4-5 months
for delivery.
I believe in their 40m yagis so much that not so long ago I bought two more
40m yagis from M2 to fulfill my long term plans. So I have one 40M3FS-125
at 125ft and another in a box. I also have my original 40M3L-125 plus a
second one, both in storage. I will upgrade all their element tips to 1/2
inch.
Also, before I bough my second 40M3L-125 M2 redesigned it's mechanics, which
were already excellent. So it is now a better mechanical antenna than it
was!
I think the $$ for the -125 upgrade is worthwhile...especially when you
consider the cost and time of having to fix a yagi up on a tower.
Hope this helps
73, Scott W3TX
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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