Re: Cellular Solutions for a Rural Location
Hi Frank,
Per your request I am posting my nearly complete recipe for 'toll' quality cellular telephone service in a difficult setting. The difficulty is the distance, 8.8 miles and the intervening topography, a forested ridge that makes Line of Sight an iffy proposition.
For the benefit of other threaders, a bit of background. I recently put into service a Nokia 252 analog cell phone. While the quality was more or less acceptable when I was outside my residence and facing the base station tower, the quality was not acceptable when I was inside the house. I ascribe most of that difficulty to the construction of the residence, which has a layer of foil covered foam insulation on the sidewalls, acting as an electromagnetic barrier. When I took the phone onto the roof, I got a high quality signal, so the solution was to place a directional (Yagi) antenna on the roof. Here are the particulars:
Larsen Yagi Antenna........................10 dB Gain
32' RG8U Cable, 2 fittings...............- 2.3dB Loss
Transistion Whip, 1' RG58, 2 fittings..- 1.1dB Loss
Nokia "Car Kit", assumed loss...........- 1.0dB Loss
Total Gain:................................ 5.6dB Gain
This has yielded a consistent quality that has been regarded by the recipents of my calls as a near if not completely "toll quality" call.
I am quite satified that we have achieved a success here.
The only quibble I have with the system at present is a minor echo that can only be detected at my end. With the help of wireless_wonk I am investigating a few possible causes and remedies. He pointed me in the direction of an interesting discussion of this arcane subject: webproforum.com
I recommend this to anyone who likes reading well written technical information that is 'layman' accessible.
One bit of arcana that I find interesting is that certain pine trees in our area have a needle of such a length so as to serve as a perfect 1/4 wave antenna/reflector in the 824-996Mhz spectrum, when covered with ice. WW has pointed out that the potential loss from such a fine forest is on the order of -6 to -9dB. So I may have to wait until spring to make a final judgement regarding the antenna system. If there is a problem, the judicious use of pruning shears, chain saws or wildfire may be appropriate, just kidding about the latter, of course. :-))
Ciao, Ray
FWIW, all well educated commentators stated that my original hope of re-radiating the energy of the Yagi via a second antenna inside my office would not work. At least not without very expensive amplification and the possibility of creating more echo/timing problems. So, tethers 'r us. |
