I'm new to this reflector, but it seems relevant to my situation.
I need to put up a modest (35'-40') antenna support structure for my VHF/UHF
antennas. I'm currently using a Cushcraft 13B2 Boomer on 2M and a 719B Boomer
on 70CM (boom lengths approx. 16' and 13' respectively). On top of that I
have a VHF/UHF vertical. All this is sitting on a Radio-Shack telescoping
Please, I don't like that store any more than you do.
The mast bottom rests on a small metal spike driven into the ground (another
RS product) and is bolted at two points to the side of an out-building. I
have 4 heavy guy wires attached directly below my Yaesu Rotator at about 25'.
The whole thing seems stable, but I can't help wondering if this is a disaster
waiting to happen!
I constructed the outbuilding as an astronomical observatory. It's about 8'
by 12'. Since the gable roof rolls off to one side (so the telescope can see
the sky), several design considerations had to be incorporated into its
construction. Suffice it to say that this is a small, but extremely rugged
little building. (It's built better than the house). This is not a
pre-fabricated aluminum shed or the like.
What I want to do is put up something like a real tubular tower as advertised
by US Tower. I am aware of what (I think) are the inherent disadvantages of
tubular towers: You can't climb them. You need a 20'+ ladder to work on the
antennas. You can't easily attach things to the sides.
So why bother? Two reasons: Neighbors and the XYL.
I can deal with the neighbors, it's the XYL that's the real problem! She
doesn't think that antennas make a positive landscaping statement. Can you
imagine that? Lately, I've come to believe that she really abhors my current
set-up. And yes, it is sort of Ugly! It looks top heavy with all those
antennas sitting on that skinny little RS mast.
This brings me to the meat of my problem. US Tower says that their 40' two-
section tubular only needs about a 16" square (or cube actually) base of
concrete when the thing is "Properly Bracketed" to the eve of your roof.
Otherwise, the base plug is considerably larger. You can imagine what my XYL
thinks of digging a 3'x3'x6' hole in the yard and filling it with concrete!
In short, I don't think I could make that fly.
So how about it? Can I pour a small footing for something like the US Tower
MA440, Bracket the thing to the side of my sturdy observatory and use my four
existing guy wires to make a safe and sturdy installation? Or am I in fantasy
land. I wonder what US Tower considers "Properly Bracketed" anyway?
Two more points: The walls of the observatory are only about 8' high (so that
the scope can look near the horizon). Therefore the bracket point would only
be about 8' from the base. I'm sure most "roof eves" are a bit higher than
this. I can modify the stud-wall construction of the observatory to beef up
the bracket mounting point, or the whole wall, if need be.
In the future, I'd like to get more (bigger) VHF/UHF antennas. (Those
multi-wavelength M2 yagis look nice!) I'm quite attracted to the weak signal
SSB work at the bottom of the bands. VHF can be like HF.
Any suggestions are welcome.
You can tell me to dig a big hole, but please don't tell me to get a new XYL!
(Get her away from amateur radio antennas, and she's the sweetest thing).
Concord, CA (CM97ax)
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