> The reason is that the typical Rohn tower configurations are for
> 'commercial' installations - not typical ham ones. In the general notes it
> mentions the symmetrical mount of 8 sq.ft. This is for commercial standoff
> mounts and omnidirectional antennas. The exposed tower above the top set of
> guys gives additional clearance for these verticals.
> I've never seen a ham configuration that was 'helped' by cantilevering
> the top section. OTOH I've seen at least one tower where the rotator was
> above the top set of guys and the wind eventually broke some tower welds
> (this was not a Rohn tower).
> Cheers, Steve K7LXC
> Tower Tech
I couldn't agree more with your observations. I think the commercial
nature of the cataloge designs was one of the points Tom, N4KG was
My comments, on this, were directed toward amateur use only.
Brian, K3KO, pointed out that another reason for an amateur to
deliberately use the cantilevered tower top configuration would be to
allow clearance to turn a quad antenna.
For the more popular amateur scenarios, the canned tower configurations,
are not what will proved the highest antenna population.
Regarding another thread about "How many guys?", IMO, there are very few
of the catalogue designs that can't be improved by adding additional guy
sets and/or increasing guy sizes.
Since most of us are trying to get the most out of our tower
investments, we really should consider professional assistance to find
the best solution for our needs. There are just too many variables and
options for anyone to expect a "one design fits all" situation to exist.
It would have been nice if Rohn had offered configurations more suitable
for our applications, but that is not the case. I find no fault in what
they did. It seems to service the bulk of their market.
But, I find the approach somewhat curious, since commercial users are
more inclined to utilize professional design services than amateurs.
Most hams only do it when it is required to get a permit. The cheapest
way out is to have a P.E. put his stamp on a catalogue design.
This may appear to be the cheapest solution, but it is not always the
Imagine having to put up two towers, when one might have got the job
The entire discussion is a bit academic, when we realize that the
antenna area figures we are using are rarely useful for tower design.
GIGO, and YMMV.
73, Kurt, K7NV
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Administrative requests: towertalk-REQUEST@contesting.com