intercom using cell phones

[abg]

see as far as antennas are concerned then i think they send the signals on the frequency decided by the service provider which is ultimately provided by the sim.. so after duplicating a sim i think i might be able to program the cell to communicate at a certain frequecny.

can you pls tell me how far can the mobile send its signals?

thanks

I doubt u can change the frequency using some written programme. It is the built in UHF oscillator sends the signal through nearest tower to sattelite and then to the distined tower and further to the Cell. Can u skip this this link? Not at all. But one idea.... change UHF to audiable RF and connect ur cell to to ele board through ur charger in ur house...using electrical transmission lines as signal carrier u can connect to ur choise of cell which also should be altered accordingly. I think u have to use cell phones permanenetly as Walkie talkie. This is possible in small area and one side of (primery) main (ring)transformer on the road of electric company. Go ahead. Try and satisfy urself.