[TowerTalk] OptiBeam OB2-40M

[David Gilbert]

I have owned an OB2-40 (the non-Moxon version) for ten years and it has 
held up just fine to ridiculous wind gusts on my southern Arizona 
hillside.  The antenna is built like the proverbial tank and I've 
measured wind gusts as high as 100 MPH.   The wind gusts are brutal here 
for about three months every spring, to the point that I usually can't 
bring myself to even look at my antennas when I hear one of those 
mini-tornadoes come roaring down the side of the mountain.  I even 
watched one lift my teenage son about two feet off the ground while he 
was weedwacking part of the lot.  It picked him up vertically (with the 
weedwhacker still in his hands), moved him about three feet laterally, 
and set him back down.  This is no exaggeration ... I saw it with my own 
eyes.

The OB2-40M is listed as having the same overall weight as my OB2-40 and 
the construction looks identical, except of course for the Moxon 
wingtips.  The wind area of the OB2-40m is 5.9 sq ft versus 6.8 sq ft 
for the OB2-40 and I would think that the Moxon configuration adds a bit 
of additional stability, so I don't see why it wouldn't hold up as well 
or better than my antenna.

73,
Dave   AB7E


> On Wed, May 19, 2021 at 7:34 PM Michael Tope <W4EF at dellroy.com> wrote:
>
>> One of the radio clubs I belong to is interested in buying an OptiBeam
>> OB2-40M two-element 40 meter Moxon Yagi. Optibeam is kind of vague on
>> wind survival specifications. Their website indicates "Windload at 130
>> km/h           430 N / 0,54 m² / 5,9 feet²". To me that implies the
>> antenna is designed to survive 130 km/h winds (80.7 MPH), but it doesn't
>> actually say that. The antenna is going to be installed at a Southern
>> California QTH at a fairly low elevation, so icing is extremely
>> unlikely. However, the antenna will be installed on a high narrow ridge
>> that lend itself to very high uneven (shearing) winds when we get the
>> occasional winter storm or Santa Ana wind condition.
>>
>> Anyone out there using one of these antennas? I am curious what you
>> think of it in terms of performance and reliability?
>>
>> Thanks and 73,
>>
>> Mike W4EF.................