[General Questions and Answers] DeathmonkeyGTX:
I know it's illegal in the US, but VHF/UHF and HAM radio equipment is f***ing expensive. I was browsing 850/1900 MHz repeaters and it looks like the maximum legal cellular transmit power is something infinitesimal like 3.5 watts.

So... What I'd like to do is fire up Garmin Mobile XT's PC-based map managing utility and map every AT&T and T-MoUSA tower within ~500 miles of my house (2,000lb cars with 1.5L engines and a 5 speed ftw, except when they malfunction outside of free towing range). Then I want to either purchase or make a somewhat large directional antenna (not sure which kind, asking here to see if the mods or somebody knows whether or not this is even possible before sinking dozens of hours of research into this) to plug into an amplifier. By amplifier, I don't mean one of those FCC licensed ones. For emergency situations out "in the sticks", it'd be handy to to have 25-50 watts of transmit power attached to a directional antenna that's pointed right at a tower. AT&T has 95% of the places I roam covered with EDGE and all of it's 15 kB/s glory, but then there are the capacious swaths of "middle of nowhere" that I like to hike in several times per year for several days at a time. Usually I bring friends, and at least every couple of years some f***tard inevitably tags along and isn't used to irregular terrain, 90+ Fahrenheit temperatures with relative humidity in excess of 90%, proper equipment (particularly cold weather gear; coldest it's gotten here in my 21 years is 7 Fahrenheit, and I still went duck hunting), and is generally unprepared falls and breaks a bone, develops heat exhaustion and/or heat stroke, or some other f***up due to being ill prepared. When I go that far out into the "boondocks", I don't take my old Civic hatchback with ~200k miles before the speedometer and odomoter died; I take my heavily modified 1986 Ford Bronco (351 CID/5.8L Windsor V8 with nearly everything that can be done to it while remaining naturally aspirated, 3 speed + "granny gear low" standard transmission so kinda a 4 speed but 1st/granny gear doesn't get used on anything like normal on or off road driving, 2 radiators + huge water pump, dual 25 gallon gas tanks + a 55 gallon drum I can swap out the back seat for if I need that much fuel onboard, Dana 60 front and rear axles, snorkel, no carpet, vinyl seats, a 6" custom suspension lift, 35" M/Ts with 1-4 spares depending on what I anticipate driving on + some A/Ts that I use for city driving when my POS civic is taken apart for repair or hauling heavy sh*t with my 450 lb-ft of torque @ 1800 RPM [gotta love getting t-boned by a drunk cardiovascular surgeon + suing the sh*t out of him in this overly-litigious society/pay for college and drop ~$20,000 into a $3,000 truck]).

That truck is supremely good at getting out of cellular range, and it sucks when sh*t hits the fan out in the sticks and I have to drive dozens of miles at high speed over rough terrain and thus tear up suspensions like a mofo to get ahold of 911 and an ambulance or a dust off (one dude broke his C7 vertebrae out there, had to get him helicoptered out) via my old Kaiser (kthx external antenna jack; I wonder if I can solder one onto Rhodium when my warranty expires) and 40" magnetic mount antenna. It'd be a lot easier to get ahold of EMS if I could build a hellacious amp and a large antenna that's collapsible/easily taken apart and reassembled to save space when not in use and I could drive to the tallest hill in visual range (if not one, check topo map for nearest), deploy that rig, aim it at the nearest tower, and make an 850MHz GSM phone call.

If it's possible, inb4 requires 1337 soldering/experience with radio equipment; I've built 1 HAM radio and repaired 8, fixed some CB's, and have hundreds of hours behind a soldering iron.

So yeah, if it's feasible to build such an inline amp please sound off.