[VHFcontesting] Height vs. foliage
stephen.tripp at snet.net
Fri Jul 22 09:07:41 EDT 2016
Hi Patrick and George,
George has given you a good suggestion using a house bracketed tower. Try
and find a Rohn45 which is
much stronger and will support a lot more without guys but of course more
costly. I have 2 of these bracketed on my
house at 20' and on my shed at 15' and no guys. The house one has supported
a 6m 5ele M2, 15' 2m yagi, 222 yagi, stacked
432 FO22, 903 looper, 1296 looper and a dual band vertical at the top. All
on a 20' mast with 14' above the thrust bearing. The other has
a 6ele HF log and now the 6m 5ele M2. I have changed the house tower to now
support only vertically stacked 12ele FO-12 on 2m and stacked
222 yagis in between with the whip at top. As far as safety goes the
original lacked but the trick I used was rope guys tied off at bottom of the
and when a big storm was coming I would run them out to trees where I had
eye hooks installed.
As far as crank up tilt over towers go, should you not be able to find a
used one be prepared to take a 2nd mortgage out. I have a 72' Tashjian
(previous Triax company) and it was pricey and a lot of work to install. I
paid over $3000 to have it shipped from CA to CT. The total cost was
close to 20k. The other option is to introduce the trees to a chain saw if
on your property. Topping trees is also a good idea. They will look ugly the
but will grow out the next and look fine, speaking from experience.
The goal is to overload the tower to just short of falling. This takes a lot
of guts with trials and errors. I have broken a lot of rules but never lost
Just make sure your tower meets the "fall zone" criteria. Neighbors get
upset when it comes down in their yard or worse on their house.
If you wish, I will send tower pictures you might not want to duplicate at
FYI, I have seen George's Rohn 25 and it too is overloaded but is guyed
which is much more forgiving.
HF-3ghz + 10ghz.
Assuming moving your home to higher ground location is not an option, a roof
tripod will be a (relatively cheap) option and give you a reasonable
improvement. A better solution would be a fixed tower (Rohn 25G) with a
house bracket at one end of the house. That could give you 25-40 ft above
your roof without guys if you don't overload it at the top. Do you climb
towers? Or you could use a Hazer or a bucket truck for antenna work. Another
way would be to use a hinged base and tilt it over for antenna work.
What kind of trees are around you and do they lose their leaves in winter?
How far are the trees from your antennas? Is your terrain flat around you
for several miles - no big hills in your most favored direction? Always
compromises to consider.
73's, George, WA2VNV
HF+50-1296, SOLP, FN30kv
146.760 Analog/448.825 UHF DMR
> Speaking of VHF contesting, and my ongoing poor results with my
> below-roof-mounted 2m beam at the home QTH, I figured I would ask the
> experts here for some advice.
> Operating under the knowledge that more height is better, I am already at
> a disadvantage being about 15-20' below average terrain. Additionally I
> am surrounded by extremely dense trees covering all heights up to about
> 50'. The city has an ordinance limiting antennas to 42', although there
> is provision for a variance.
> Assuming I come across $5-10k, I believe I could legally get away with
> putting in a freestanding 70' crank-up tower, but so far I have other
> financial priorities, and I haven't yet won the lottery.
> So here's the punchline: Is it worth getting a small tower or roof-mount
> quadpod (total height 25-40 ft), knowing the antenna will still being
> surrounded by trees? Or will I be happier in the long run saving my
> pennies and concrete, and just roving until I can afford something taller?
> Due to my lot configuration, guying is not an option, but are there any
> other permanent-mounted, great-lakes-weather-resistant, tall options out
> there I should consider? I expect to operate up to 23cm, as possible, but
> would expect most "serious" work would be only up to 2m.
> Thanks for any advice,
> Patrick / KB8DGC
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