[VHFcontesting] Hilltopping 101

[Eric Smith]

On Tue, 16 Aug 2005 21:34:50 -0400 (EDT)
 Ken Alexander <k.alexander at rogers.com> wrote:
> I probably spent as much of the UHF Contest driving
> around looking for a good location to operate from as
> I did operating.  Maybe it's no wonder, considering I
> had no suitable coax cables until the night before,
> and only half my antenna system when I woke up the day
> of the contest, but that's just me.
> 
> Anyway, it's fairly hilly around here north of
> Toronto.  Average terrain would be approximately 250
> metres ASL, with most peaks at around 300 metres (985
> ft ASL).  Some are as high as 400 metres but that one
> is on a highway and has noisy powerlines running down
> the side.
> 
> It got frustrating driving around, and after a while I
> decided to head closer to home and operate from a nice
> bald hill at 320 metres.  I reasoned that it wasn't
> necessary to be perched at the top of the highest peak
> in the area...being "above average terrain" was good
> enough for what I was doing.  Any flaws in that
> reasoning?  What should I be looking for as I scout
> out potential rover sites in the next few weeks?
> 
> The other problem with most hills around here is that
> they've covered in tall trees, which I've heard is no
> good on UHF...but I'm wondering how much of a
> difference trees and foliage really makes on 70cm,
> which was where I was operating?
> 
> Thanks for any help.
> 
> 73,
> 


Guess that would depend on how much forest you have to
blast thru to get to clear air...
This is where the higher gain directive arrays help out...
 A few trees here and there or a small thicket in some
desired direction will attenuate somewhat at 432, but
really kills things at 903 and above.  BUT my experience
operating from a county park surrounded by forest 100 feet
tall in all directions for a 1/4 mile, is that the
mountaintop (4000 ft. high and 25 miles away) could still
be heard loudly on 2304 due to tree scatter.
Once beyond the tops of the trees I could see, the signal
had nearly no path loss to the hilltopper.  Your situation
likewise may be different.  But, being higher than
everything around you despite the trees will help out
greatly.  That much less stuff in the way.
Eric
KB7DQH