Doing a little research, I found why my nextel phone screws with everything.
Its transmitter is almost twice as powerful as my 8260, and that is when the 8260 is running at full power, which it often isnt.
The nextel operates at 0.744 watts in the 806Mhz to 821Mhz band.
The nokia operates at a maximum of 0.132 watts in the 824mhz-849mhz band, and 0.437 watts in the 1850mhz-1910mhz band.
God, I gotta keep this thing away from my nuts. ๐
hehe, I've often wondering if I could modify a radio amp (like maybe a ham radio amp near that band) so I could have a cell phone outputting like 50 watts or so ๐
Okay. We'll do the math here a second.
Modern cellular phones operate in the 1.8Ghz band (besides nextel, which is actually an iDen 2 way full duplex trunked radio, basically).
At those frequencies you near the resonant frequency of water.
What's your body made of? :->
We'll do the MPE (Maximum Permissible Exposure) calculations here a second:
http://www.tcstx.com/exposure/calculations.htm
50 watts
We'll say the antenna 11dbi gain (This is a directional yagi, pointing at the cell tower), which is fairly conservative.
The frequency is 1850Mhz (this is Digital PCS band)
You'd have to be a minimum of almost 6 feet from the transmitter if you were aware of the transmission, and it was controlled. Innocent bystanders must be at least 12 feet from your antenna to meet FCC regulations.
(Oh, and since it's in the gigahertz band, don't point the directional antenna at your head, or you risk blindness)
Let's say you were stuck in analog only area. (This is most likely if you're using an amp)
50 watts, 11dbi gain, 824 Mhz.
Yep, you'd have to be 7 feet from the antenna, and that's if you were aware of the danger. Innocent bystanders would now have to be at least 15 feet away at this point.
But you'd also cause your transmitter to go out of it's licensed parameters, and be violating FCC regulations. At that signal strength, it would only take a 15 minute phone call to triangulate your position. I'd keep $10,000 around to pay the fine. (Yes, that's the amount they seek for rule violations)
Don't mean to pick on you or anything, but gotta know this stuff in ham radio. Safety first. We get lots of power to play with. I can legally run a 1500 watt transmitter if I wanted, in the appropriate ham bands. Granted, this could literally cook a human that comes within 3 feet of the antenna.
That's okay, people have to stand 19 feet from my car antenna during transmission at full power, and it's only 25 watts. Or, you can be in the car, because you're below the ground plane.
dammit Paul, you take the fun out of everything ๐
I dunno. I thought my fun fact about cooking human beings pretty fun.
wait a sec…..I thought the following was true…
These new digital phones with 4 hour talk times must be transmitting at an awfully low wattage (obviously not with my i90).
The further up you go in frequency (800meg already being kinda high) the more direct line of sight you need on the receiver.
number one is my figuring, but the line-of-sight thing I thought wss true.
So whys it that nextel is at a lower frequency and transmitting at WAY more of a wattage than your PCS? nokia and nextel loses signal so much (digital artifacting, intermittent transmission, etc)
I will remember this wattage figure and remember to keep it away from my head!
What's this about being cooked? How does that happen? I am just missing something cause I've been around some radio emitters (CB @ 100 W) and never got even sick.
And aren't all phones just radios? Nextel included?
sorry for asking so many questions and being so serious, just wondering how this shit works….I'm going to get back to watching my CD V-700 click away next to this Torbernite.
Mike
Nextel spaces their towers further apart. They're every few miles apart, whereas PCS has a mini-cell every half mile or so. I've seen PCS towers on power poles. They're that small.
I was being sarcastic about being cooked. It takes a hell of alot more than that. However, at the lower CB frequencies, you're getting there. Be careful, you're playing with fire.
But yes, normal PCS phones have dual stage transmitters that step down the wattage to just barely over what is necessary to make the call, thus saving battery life. Take that thing where there's no PCS and see how long it lasts. My 8260 lasts less than 24 hours on standby in an analog zone. The same phone can do a week plus in PCS areas.
Sorry about the lack of detail, but I'm late for work. later!
s/sarcastic/tongue-in-cheek/
And aren't all phones just radios? Nextel included?
Yes, they are. Nextel/Motorola's iDen technology is alot like the trunked radio systems police are using nowadays, however. They look and act normal, but underneath they operate quite differently than a normal cell phone.