[HamWAN PSDR] KU7M and his dBm

[Bart Kus]

Dean,

I wouldn't limit your potential upside to 3dB with ... "spatial 
modulation".  :)  The vast majority of your path loss is NOT due to 
distance.  If you did achieve clear (or better) LoS, you could be 
looking at 30dB deltas.  Remember we've had Baldi-Tacoma (a far longer 
distance than yours) run at -57dBm during a signal survey. K7JMM, across 
the Puget Sound (about 3x your distance) is running at -58dBm right now.

Kenny,

Would you like some tower climbing / install help?  That's some crazy 
uptilt on the antenna picture you showed!

--Bart


On 5/21/2014 9:27 PM, Kenny Richards wrote:
> 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 
> <mailto: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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>
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