[RFI] Alarm Systems and EMI/EMC

[Michael Tope]

Jim Brown wrote:

>On Sat, 09 May 2009 12:28:05 -0700, Michael Tope wrote:
>
>  
>
>>Anyone know any home security equipment dealers who are hams or who
>>know anything about EMI/EMC?
>>    
>>
>
>No experience with these guys, but security systems are notorious 
>for RFI susceptibility.  FWIW -- that 300 MHz range is commonly used 
>for garage doors and remote control of A/V systems. I don't know of 
>instances of RFI to the RF functions, but expect problems with  RFI 
>to other circuitry. The usual fixes are twisted pair wiring, caps 
>across wiring from dry contacts, and chokes to kill common mode.  
>
>73,
>
>Jim K9YC
>
>  
>
Hi Jim,

The feedback I am getting suggests the wireless systems are superior to 
the wired systems in terms of EMI-EMC. This is not surprising since your 
are getting rid of long lengths of twisted pair wires when you go with a 
wireless sensor system. I don't need to tell you that it is those wires 
where the trouble often comes from.

73, Mike W4EF.................