[Towertalk] Guy wire resonance...morphed to stacking quesiton...

[R.D. (Ron) Rossi]

Folks,

I already have my top guys of phillystran. On top is currently an A3S with 40m 
add on at 92'. I am planning on replacing that with a TH6 at 90' and a Hygain 
402BA 10' above it. I can probably get the spacing to 12', but much more is 
going to be a bit more problematic on the existing tower. Any comments on the 
spacing? Is it enough? Modeling data?

I checked the archives and found some pretty good hits. I see comments from 
K3ND in 1999 about a slight shift in TH6 SWR on 15m with a 402CD at 10' 
spacing. K1ZM also comments about a TH6 and 402CD being fine at 10' spacing in 
1999 when discussing the then new XM240. Sam Ferris tried both a 402BA and 
XM240 with 6' spacing and the booms perpendicular in 1998.

I played around in NEC4WIN, but don't trust results using full sized antennas. 
I would love to read more recent comments and possibly some modeling work.

-- 
73 es God Bless de KK1L...ron rossi(kk1l@arrl.net) <><
QTH: Jericho, Vermont
My page: http://www.qsl.net/kk1l


>>>Pete Smith said:
> At 07:50 AM 6/25/02 -0400, Saul Abrams wrote:
> >I replaced the first two 27 foot sections with Philly and the
> >clover leaf disappeared.
> 
> 
> For what it's worth, another supporting anecdote.  I have a Force 12 
> EF-240S, at 104 feet, on a Rohn 25 tower with top guys at about the 95-foot 
> level.  Originally, I had 21-foot semi-rigid fiberglass insulators starting 
> at the tower, and then one-piece steel guys to ground level.  I didn't 
> notice any SWR perturbations, but the antenna didn't seem particularly 
> directive, nor did it perform well in contests.  I replaced my top guys 
> with Phillystran, and the antenna came to life.  this seems to indicate 
> that even 25-30-foot spacing away from guy wires may not suffice on 40m.
> 
> 
> 73, Pete N4ZR
> 
> Check out the World HF
> Contest Station Database at
> www.pvrc.org
> 
> 
> 
> 
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