[HamWAN PSDR] KU7M and his dBm

[Kenny Richards]

Dean,

I'm slightly less mad at you, but still a little peeved. :-)

The shot to Capital Park from my house goes through quite a few tree's in
my immediate area. (All within a couple blocks from me)  When I originally
installed the tower about 10 years ago, I was able to see downtown from the
top of it. Now I can't, due to the trees of the neighbor directly behind me
and his neighbor.

That said, I don't actually have the HamWAN antenna mounted on the tower
yet. I had to postpone that installation until my knee heals up. (Had the
meniscus repaired in my left knee last week)  Right now the antenna is
mounted to a small mast at the apex of the roof. (It is sharing the mast
with a VHF/UHF vertical)

I thought that I'd posted links to these pictures before, but I guess not.

Picture of current installation:  http://www.ku7m.net/drop/KU7M_HamWAN.JPG

Picture of what I'm shooting through to get to Capital Park:
http://www.ku7m.net/drop/KU7M_CPView.JPG

And just because it makes me laugh, the installation from the first night
it started working: http://www.ku7m.net/drop/DeckAntennaMount.jpg

The difference in signal strength from the antenna being on the deck
railing to its current location is ~5 dB. The height difference between the
to location is about eight to ten feet. When moving the antenna to the roof
the first time, I had originally installed it on a mast located at the far
east side of the roof. In this spot I could not hear CP at all. By moving
the antenna to the mast located in the center of the house (which is about
20-25 feet west), the signal appeared and has so far been the best
location.  I ordered another mast mounting kit for the eve located at the
far west side of the house. When I'm feeling better I'll install it and see
if the signal improves again when moving west.

I don't have many data points on the impact of wind on the signal strength.
I did check it on Sunday when a system blew through which was causing the
trees to noticeable move. But I wasn't seeing much change in the signal
strength. (maybe 1 db?)

Thanks
Kenny



On Wed, May 21, 2014 at 7:44 PM, Dean Gibson AE7Q <hamwan at ae7q.com> wrote:

>  First of all, Kenny:  welcome!  Now that you have a HamWAN connection, I
> hope you are no longer mad at me.  Where is your antenna (inside/outside,
> height above ground, etc)?
>
> On a related but more serious side, do you have a direct line-of-sight
> path to Capitol Hill, or do you go through trees?  The reason I ask is, my
> path goes through some trees.  When it is windy, that causes my RX signal
> level (dBm value) to vary about 5 dB (mostly down).  I have wondered
> whether mounting my antenna higher would help my overall value (of course
> it would help when it is windy).
>
> My average RX signal level is 80 dBm (no winds), and yours appears to be
> 83 dBm.  However, you are twice as far from your cell site as I am from
> mine, and since power falls off as the square of the distance, I'd expect
> (in similar configurations and siting) that you would experience a 6 dB
> difference.  Since the difference is only 3 dB, that suggests that (all
> things being equal, which they never are) I might gain *at most* 3 dB by
> moving the antenna.
>
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