On 5/22/2011 3:11 PM, Sal M. Onella wrote:
On May 22, 11:04 am, 'Captain' Kirk
wrote:
I'm living in a wooded area and am trying to hit our club repeater
reliably. It's cloudy now so I'm and getting a bit of ducting but I
have a lot of trees, mostly poplars, in the direct path. I would have a
line of sight if not for the trees as I'm up enough in altitude. I can
cut the trees, they're mine, but finding the right ones is difficult and
i don't want to waste the whole grove.

I go from keying the repeater with no intelligible signal to not being
able to hit it. Today I actually have an S meter reading due to the
clouds. I am currently using a J-pole and will put up a Yagi soon but
wonder if NVIS would work on 2m? I have only seen references to it
being applied in HF.

'Captain' Kirk DeHaan
N6SXR

I can't see that NVIS has any VHF backers.

Can you exploit Google Maps, satellite view, to establish a precise
line bearing from your antenna to the repeater site? If you need even
more help than you get from your new yagi, then such a line bearing
will help identify your "trouble trees."

I had to do it for a new FD site a few years ago. We're in San Diego
and I wanted to work 2m into Los Angeles. First, I used a protractor
to determine LA was X-degrees True (whatever it was) from us; next, on
a close-up print of the FD site, I plotted that same line bearing from
the antenna site to obvious local landmarks which we then used on the
the ground for pointing the 2m beam.


For this kind of thing "RadioMobile" from VE2DBE is the application of
choice. It will load the SRTM terrain DEMs, etc. and plot out the path
quite nicely.
http://www.cplus.org/rmw/english1.html


But, if you can get in sometimes, but not others, the next question is,
"can you hear it"?

How long is your coax?
If more than 20 ft, are you running a preamp?

Getting 10-15 dB gain over a jpole would be easy with a moderate length
Yagi. A M2 2M4 (4 elements, $115) is about 10dBi. A 2M9($240) is about
14dBi