Just recently I have been setting off my security alarm when operating 40
meters. The system has been in use for almost 4 years and previously there
has never been any problem with RFI. The system is an ADT with a Focus 32
control unit. The control unit is wired to a keypad but all security
checkpoints, ie. doors and motion sensors are wireless. The 40m antenna is
an Alpha-Delta DX/DD configured as an inverted-vee one leg of which passes
over the house. I never run more than 200 watts as this is the maximum that
the Yaesu Mark V can produce.
Generally the problem occurs only at the low end of 40 in the CW and RTTY
portion of the band. Nothing in my station or in the security system for
that matter has changed but obviously something has. Ideas would be welcome.
RFI mailing list