[HamWAN PSDR] East Tiger Mountain cell site on the air

[Rob Salsgiver]

I suspected as much… what are you after – I’ll keep my eye open…

 

From: PSDR [mailto:psdr-bounces at hamwan.org] On Behalf Of Bart Kus
Sent: Monday, June 22, 2015 2:48 PM
To: psdr at hamwan.org
Subject: Re: [HamWAN PSDR] East Tiger Mountain cell site on the air

 

Nah, we'd need some beefy self-supporting thing that can withstand ice loading.  It's a serious mountain in the winter.

--Bart



On 6/22/2015 1:06 PM, Rob Salsgiver wrote:

Do you have any use for Rohn 25 sections, or is that too small?

 

From: PSDR [mailto:psdr-bounces at hamwan.org] On Behalf Of Bart Kus
Sent: Monday, June 22, 2015 12:49 PM
To: Puget Sound Data Ring
Subject: Re: [HamWAN PSDR] East Tiger Mountain cell site on the air

 

Hi Dean,

I think it would help in discussing these comparisons if you were to express the RF power not in terms of absolute power, but in terms of power spectral density (W/Hz).  The 1W modem is set for 5MHz bandwidth when communicating, so its PSD is 0.2uW/Hz.  Your 0.1W handheld is set for 25kHz bandwidth, so its PSD is 4uW/Hz.  That's 20x higher power density.  If the noise floors of both spectrums were equal (which they aren't) that would mean a 13dB increase in the ability of the FM radio to discern a signal, compared to the modem.

So 70cm FM has a lot going for it here.  It has better NLoS propagation combined with a theoretical 13dB PSD boost.  On the flip side, you have the 30dBi gain of the modem dish helping you to compensate for those losses.

This weekend I'll be running our first tests of the 900MHz gear in NLoS conditions.  I did some lab tests on it over the weekend, and it looks like @ 5MHz bandwidth it transmits just about 1W.  The signal, being OFDM, isn't very tight, so we'll have to be very careful with 900MHz repeater co-location.  We'll also have to watch out for colocated 800MHz users.

Regarding you linking to ETiger, there's a bunch of trees in the way, but give it a try!  The mountain tower unfortunately does not clear the surrounding tree line.  If someone feels like donating a 60ft tower for up there, I'm sure that'd help.  :)  Also, keep in mind that due to the tree issue, ETiger was only installed as a single sector site.  Sector 3, aimed at 240 deg.  Have you tried aiming @ Haystack yet?  Nigel just moved and is linked up to it now from Everett.  We need to do some tree pruning @ that site to raise its signal levels.

--Bart




On 6/22/2015 11:04 AM, Dean Gibson AE7Q wrote:

Recently I noticed that I can access the WA7HJR (444.65MHz) repeater on East Tiger, from my home in Mill Creek, with the Icom and Yaesu handhelds at 0.1W.  Reports are that it is a bit scratchy, but pumping the power all the way up to 0.5W gives a reported clean signal.

OK, that's 70cm, not 5cm.  However, I've long been able to access KB7CNN (1292.2MHz) at the same site with 1W.

All antennae above are omni.

Meanwhile, my connection to the Paine site has dropped in the last month from -77dBm to -84dBm.  If last year is any indication, I have about 30 days until I lose the connection to Paine for another six months.  Originally I thought this was due to seasonal foliage growth, but since reception didn't come back until late February, I think it's something else.  Just to one side (a couple hundred feet) of my direct path to Paine, is a huge water tower just south of 132nd Street, and I'm wondering if that was serving as a reflector when it was full, and not so much as it emptied during the summer (or maybe partially resonant or energy absorbing?), and not refilled until the winter.  That hypothesis fits the timeline better than foliage ...

Anyway, when I get the time this summer, I will try moving the 5shpn & antenna to the south side of my house and try to connect to the HamWAN site at East Tiger.  Using Google Earth, I see that the bearing from my house to East Tiger is 156 degrees.  I also see that the bearing to the Baldi site is 160 degrees, a four degree difference.  Google Earth's elevation plot shows a clear path to both East TIger and Baldi, the latter path barely clearing the terrain just west of East Tiger.  VE2DBE's Radio Mobile Online ( http://www.ve2dbe.com/rmonline.html ) plot agrees.

This brings up the subject of common sector frequencies.  Theoretically, the narrow beam of my antenna dish (isn't it about 3 degrees?), coupled with East Tiger being only 28.3 miles away compared to Baldi at 47.8 miles, I would think would resolve any interference.

Thoughts?

On 2015-05-31 19:50, Bart Kus wrote:

We put a new cell site on the air this weekend.  It's @ East Tiger Mountain, and radiating @ 240 degrees (Sector 3) only.  It's linked directly to the Tukwila datacenter, and has a second link to Snohomish DEM ("Paine"), but that's not yet configured for routing. This site is 1500ft higher than our existing Mirrormont site, and will serve to replace it.  It's superior location and superior connectivity are a double-win.  Mirrormont has been re-configured to be on the Sector 2 frequency temporarily so as not to conflict, but will go off the air at some point in the near future.  If you're in the coverage area try to give it a go and report back! 

--Bart 








_______________________________________________
PSDR mailing list
PSDR at hamwan.org
http://mail.hamwan.net/mailman/listinfo/psdr

 






_______________________________________________
PSDR mailing list
PSDR at hamwan.org
http://mail.hamwan.net/mailman/listinfo/psdr

 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.hamwan.net/pipermail/psdr/attachments/20150622/ad337380/attachment-0001.html>