(Passive) Antenna Repeaters? (Cell phones and 802.11 type stuff)

[HanClinto]

Hey all!

I'm new to the "Everything Else" forum, but I've been a regular poster on the Video forum for over a year now. Nice to make y'all's aquaintance!

Okay, let me explain. No, there is too much. Let me sum up. My girlfriend lives 3 1/2 hours away over country-road driving. I have crap cell phone reception during several sections of the trip, but being an amateur radio operator (of sorts, I haven't done anything with it in years), I would like to make my own repeater (or maybe just a tuned passive repeater setup) for my car to boost my in-car signal so that I can hit the tower. Usually my problem is not hearing other people, I just can't get my signal strong enough so that they can hear me.

I'm on the Sprint PCS network, so it needs to operate in the (I think) 1900 mhz frequency.

I've found a few websites that deal with the topic:
These are mostly commercial passive antennas:
http://www.sb-systems.com/motorola-v...e-antenna.html

Here's an e-bay of a one that operates in the wrong frequency range (though I could just make my own antennas to operate in the correct frequency)
http://cgi.ebay.com/ws/eBayISAPI.dll...category=48491

Here's the relevant Ask Slashdot question, though they only say that "Hey, you might try building your own two-way amplifier", but other than saying it might work to make it like a cable TV amplifier, there's not any other good clues in there:
http://ask.slashdot.org/askslashdot/....shtml?tid=126

Any other thoughts, gentlemen? I'd be interested in working on a project like this, if there were a couple other solder-monkeys who would also like better cell phone reception in their house / car / office / shower / whatever.

Respectfully,
clint herron

[eplpwr]

Hi HanClinto!

From what I know the PCS 1900 is just a re-labeled GSM system, with a slightly different carrier frequency (1900 MHz as opposed to the 900/1800 MHz used in GSM systems). The renaming of GSM was neccesary to make the yanks believe it was a domestic US cellphone system...

PCS/GSM allows for a maximum distance of 35 km (approx 25 miles) between the cell phone and the base station. I'm just pointing this out because sometimes communication problems are not related to signal strength per se, but rather to too distant base stations, which is rather difficult to fix as a cell-phone end-user. If you're too far away your signals will arrive at the base station out-of-sync.

Ask your cell-phone operator if they have a coverage map for the area, to see if their *intention* is that there should be coverage for your route.

[HanClinto]

Cool! Thanks for the info re: the cell phone information. I didn't realize it was an issue of the signals being out of sync -- that makes a lot of sense.

I guess my next question, is can it hurt my cell phone reception to put a passive repeater inside of my car? And would the glass and metal shielding of the truck cab really dampen my signal that much that a passive repeater might help?

Respectfully,
clint