Hi guys
i am trying to design a wireless security system.
First, i would like to have a wireless intercom for visitors. if you can refer to certain sites where i can be able to build my own RF transmitter or suggest an alternative route.

Second, i would like to have a wireless keypad where by if you want to open the gate you have to punch your code then it will open. also i would like which sites i can refer to.

 

If you are to build a wireless transmitter for your intercom, I would recommend developing an AM transmitter instead of FM. These bands, after all, don't require a license in order to transmit on-that is, if you don't exceed the power ratings according to FCC regulations (depends on your location; I'm not absolutely convinced you live in the USA). AM is actually less noisy and less crowded compared to FM. It's also much easier to transmit in between radio stations.

Austin