[TenTec] RF gets into computer (ADT Alarm System)

[Dr. Gerald N. Johnson]

On Sun, 2007-04-22 at 13:00 -0400, W4ABW at aol.com wrote:
> I use the FT-1000MP and I get RF (I think) into the ADT Security alarm  
> system. It sets off the alarm when its not armed. Any thought on this?  Its  only 
> troublesome on 40m where I use a dipole that's closer to the house than my  80m 
> dipole and my tri-band beam. My 80m dipole is just a lil farther away and  
> has never caused this effect. The  firemen have been out here twice  now.
>  
> thanks
> Al
> W4ABW
> Raleigh
> 
Moving the 40 meter antenna may help, but it sounds as if the alarm
wiring needs some RF filtering with bypass capacitors and toroids or RF
chokes. Its probably some wire in the alarm system is nearly resonant on
40 meters, probably about 30 feet with an open away from the alarm box,
or a half wave loop. You will need to get ADT to work on this, I
suspect.

73, Jerry, K0CQ