[RFI] DSC Alarm Panel 75 Meters/False Alarms

[Brad Roope]

Hello:

I am having a problem with a new DSC Alarm Panel recently installed at my next door neighbors QTH. On 75 meters with more that 400 hundred watts causes the false alarms being sent to alarm central and in one case a panic alarm to the Police Department. The specific causes as to when it sends alarms is unclear. The new system is continually polling the sensors and I suspect that when I am transmitting the data gets corrupted as sends a false alarm.

DSC was informed that there could be legal issues associated with false alarms if the RFI issue is not resolved.

A letter was sent to the RFI Department at ARRL. A letter has been sent to DSC requesting help to solve the RFI Issue. The alarm company that installed the system called DSC and was told there was nothing that could be done. However, he said that he had a filter in the truck and installed a common split core around the leads at the input to the panel. In addition he grounded the new panel to the common telephone/electrical ground.

If DSC does not respond to their RFI Issue, I may ask my neighbor if I can install #77 beads at the input to the Alarm Panel. I may get only one opportunity so I need to know if multiple beads on each lead would be better that just one?
I may also install by-pass capacitors on each lead. I am not sure if I will be able to install beads at the sensor end.

Any comments would be appreciated.


Brad Roope
W1RQ
11 Singingwood Drive
Haverhill, MA  01830
http://home.comcast.net/~w1rq/wsb/index.html