I have gotten a lot of great thoughful responses to my request...Thank
you all.
I got quite a few suggestions about stacking 2 2 element 40 meter beams
and I agree that is a good thing to do but not in my case. After
modeling and playing with HFTA and my terrain I just don't see that it
is worth the complexity and cost for the performance I would get
starting a 40 meter stack at 90 feet. If I had 150+ feet then it would
make more sense for me. I am planning to use the 80 foot and lower
parts of the tower to stack two other beams for 20 through 10 and I will
look at options there but I probably won't get that far this year.
Therefore for me I am starting at the top so to speak and making a
single 40 meter antenna choice to be installed at 90 feet.
I got one suggestion to look at the Monster IR and I have watched the
development and deployment of that antenna closely. I don't want to go
there because of cost, weight, complexity, bigger mast, bigger rotator
and have all of my operation in one antenna so to speak. I will
consider a steppir for the smaller antennas. I like the idea of the
steppir and would like to try one because I think it is a very cool
idea...i just want to try one out.
The question of 40 m full size vs linear loading is a question of cost
and size. I'm trying to get reasonable performance for reasonable
cost. The goal of this station is not to be in the top 2 % of contest
stations...I don't have that kind of time, real estate, or money. Size
is an issue not becaue of the tower but because of my yard. I cleared
a lot of trees for this tower...lots of work but I didn't want the
property to be a wasteland either. Putting together any 40 meter bearm
and getting it tuned and up the tower is going to involve working with
some remaining tree cover. A full size antenna will be more difficult
to accomplish and more money...not sure it is worth it for me.
As for 2 or 3 elements I have got a lot of input that says for a single
antenna go with the 3/4 and that it kinda how I feel about it.
So here we are picking our 3/4 element linear loaded antennas. My QTH
is in New Mexico mountains at 7200 feet and I do get some ice, wind, and
snow. How bad?...I don't know this is the only ice and snow I have ever
lived in. The only reason I would consider the optibeam is that it
is probably the most rugged linear loaded 40 m beam there is. I am
worried about longevity because I don't want to have to climb up there
and mess with that antenna every couple of years but how much is that
worth double the price?. The forty will be on top and harder to get to
than any of the other antennas. If it had to come down probably the
other antennas would have to come down too....I don't want that.
However the Omnibeam is twice the cost of the M2 and I'll bet the
performance except for mechanical reliability is the same or close. So
the question is what about reliability of the M2 and Force 12 3/4
element antennas. Does anyone have any reliability longevity issues
that you have not yet shared about those antennas in similar
conditions? Other than that I still have not settled on a decision
and I still have some time to think about it (The tower isn't up yet but
I'm working on it now). Anyway I sure appreciate all of your input so
far and sorry I have not been able to respond to everyone. If you have
more thoughts or haven't responded yet keep the comments coming I have
enjoyed all of the ideas I have received.
TNX
-Dave WD7Z
_______________________________________________
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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