[RFI] RFI & Alarm Systems?

[KD7JYK DM09]

"What frequency(ies) are these wireless secirity systems operating in - 434, 
390, 902, 2400 MHz?  And how are the sensors powered, via coin cells?"

It really depends on the system.  I have bits and pieces covering many 
decades, frequencies from 20-30 KHz pulsed magnetic inductance to 
microwaves, power supplies from coin cells to big lead acid batteries.

Check the FCC ID# online to get the operating frequency range:

http://transition.fcc.gov/oet/ea/fccid/

Kurt