Re: Mobile signal boosters/amplifiers - are they effective on the road?
- From: Larry <noone@xxxxxxxx>
- Date: Sat, 07 Jul 2007 12:03:03 +0000
techman41973@xxxxxxxxx wrote in news:1183761049.095528.282010
@m37g2000prh.googlegroups.com:
when dropping in fringe areas or in mountain regions
Cellular phones are on the UHF bands. They are Line-Of-Sight, no matter
how much power you are allowed to run. It IS true that UHF will
"troposcatter" if you use enough power, in the megawatt ranges, over-the-
horizon. The military has used it since WW2:
http://www.radyne.net/application_details.aspx?id=2
But, that's not an issue for us under 3 watts. You CAN get some
advantage with more power REFLECTING off things that reflect, anything
made of metal. But, with the bands just jam packed with signals, and now
using controlled digital comms that has the distinct advantage to measure
your range and ignore you, extra power becomes less and less of an
advantage.
Out in the countryside, especially in flat country like I live in, power
DOES make a great difference. Our enemy in the flatlands is attenuation.
Trees, especially trees, and the air, itself, gobble up your signal as
distance increases. Your signal is mostly wasted, in any event. You
have an omnidirectional antenna that sprays power in all horizontal
directions (if you will quit laying the antenna out sideways and laying
on it.) The vertical whip's radiation pattern looks like a donut laying
on a table, made of balloon rubber. As your donut expands further and
further from the antenna, the donut rubber stretches and becomes thinner
and thinner, just like your RF field becomes more and more stretched,
weaker and weaker. At some point, even though the signal, theoretically,
never goes away, it becomes so weak it is buried in the background noise,
especially in the daytime when we're pointed at that monster of RF noise,
our Sun.
As your signal passes through the forest, every nicely resonant pine
needle acts like a little antenna connected to a carbon pile dummy load,
converting your ever-decreasing RF into heat...immeasureable but true.
On the other side of a stand of trees, your signal just disappeared! PCS
users have even more problem. Their signals are a much higher frequency
than 800 Mhz old cellular users. It attenuates much faster, so the
company has to put up towers much closer together to compensate. PCS
users must be within about 2 miles of a tower to get respectable service.
In these flatland conditions, yes, the amp makes a very respectable
difference. You have no problem hearing the cell's more powerful signal
into a much higher, properly designed, directional antenna...covering
only 120 degrees, not 360. The cell hearing YOU buried in all the noise
from all the other users is simply an amazing feat, with your crappy
little hidden antenna buried next to the circuit board laying between
your head and shoulder, itself buried in another RF absorber...YOU!
By plugging your cellphone into a booster amp, and having the booster amp
plugged into a much more efficient, higher gain antenna OUTSIDE the metal
shield of the car or office building, you present a much more powerful,
much less fading signal to the poor cell receiver inundated with noise
and other users. It simply works better....but it won't go through
mountains...or even hills.
Larry
--
While in Mexico, I didn't have to press 1 for Spanish.
While in Iran, I didn't have to press 1 for Farsi, either.
It just isn't fair.
.
- Prev by Date: Re: Service in Mexico
- Next by Date: A hidden "screw you" from Apple
- Previous by thread: Re: Mobile signal boosters/amplifiers - are they effective on the road?
- Next by thread: Service in Mexico
- Index(es):
Relevant Pages
|
