[RFI] CO Detector

Roger Parsons ve3zi at yahoo.com
Fri Feb 9 14:07:08 EST 2007

VE3WO has several neighbours with 'Kidde' line powered
CO monitors. He finds that they trip when he is using
as little as 50W on 80 or 160m, and perhaps 100W on
the high bands. He contacted the manufacturer and
received the following reply (part):

"In the case of interference from a amateur radio
operator the amateur radio operator must make all
possible efforts to mitigate the interference.
This gentlemen must ensure that his equipment is not
generating spurious emissions or RF power in excess of
Industry Canada's requirements."

This is an interesting response, in view of the fact
that CFR47 part 15 (and the corresponding IC document)
puts the onus entirely onto the manufacturer/supplier
of the class B equipment. We have quoted chapter and
verse to them and will see what transpires.

Realistically, we are on our own. I am not willing to
do anything which remotely compromises code or to
internally modify the instruments (although that would
probably solve the problem quite easily). 

My thoughts are:

(1) Pass the power line to each unit through a toroid
- several turns if possible - on the low bands the
interference is almost bound to be entering through
the power line. I appreciate that parallel capacitors
are also highly desirable, but that would violate

(2) Try alternative CO detectors. To that end does
anybody have any recommendation on one(s) that seem to
be rf immune? (It would be justice for Kidde to pay
for them, but that is a bit unlikely!)

Travis has been off the air for quite a while because
of this problem, and regardless of the rights and
wrongs he does not want to upset his excellent
relationship with his neighbours.

TIA 73
Roger VE3ZI

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