RF remote control HELP

[alah]

Hello everybody. I want to control a few relays at about 1km ( 1000m ) away but the line of sight is blocked by trees. I´m working on the 433MHz tx/rx modules, like the TWS/RWS434 with encoder/decoder ICs, because I´ll be able to have a few receivers with just one transmitter.
I doubt that the tx power would be sufficient so I´m wondering if I could connect the output of the
TWS to the input of a 1 or 2w amplifier. Can you recommend one? any suggestions as to frecuency, transmission method? I´ll have to get stuff from USA, any recommended supplier?
Thanks, Alberto.

 

[papunblg]

If you have mobile network then it would be legal to use GSM module. In most of the places it illegal to use a powerful FR transmitter.

 

[alah]

Sorry, forgot to mention; NO communications down there.

 

[BigBoss]

Try to use lower frequency like 27MHz.Or increase your output power with an efficient antenna if the max. output power is not constrained.

 

[ALOK KUMAR SRIVASTAV]

Electronics Fusions
here you can the circuit diagram and working of 433mhz remotecontrol