[CQ-Contest] New furnace...

Rick Lindquist, WW3DE ww3de at comcast.net
Fri Dec 11 08:07:51 PST 2009


Today's electronics - including some devices you wouldn't typically consider
as noise sources - can generate lots of QRM. When we lived in Massachusetts,
our then-recent model (2000 model year) Kenmore washing machine generated
junk well up into the HF range; I had to get my xyl to alter her laundry
schedule. Our Samsung washer here in Delaware does not appear to be
generating any bothersome ix, but the Flexera solar array two houses away
creams 160 and 80 during hours of daylight.

73, Rick, WW3DE

-----Original Message-----
From: cq-contest-bounces at contesting.com
[mailto:cq-contest-bounces at contesting.com] On Behalf Of Art Boyars
Sent: Friday, December 11, 2009 10:24 AM
To: cq-contest at contesting.com
Subject: Re: [CQ-Contest] New furnace...

K0RC said:

"I am considering replacing [my] furnace....  There has been
advancements in technology in the past 17 years. This includes a
variable speed DC blower motor upgrade from a multi-speed AC motor.
Does anyone have any experience in the newer technologies in regard to
my HF gear? Specifically, a variable speed DC motor sounds like it
might be an RFI generator."

No experiece with the variable speed motor, but here is some related info.

I had a new furnace installed (10 ft behind my seat at the rig) about
a week before CQWW SSB.  Coincidentally, I began to hear wide-band
splatter on modulation peaks from the 50KW AM station on 1500 KHz,
less than two miles from my house.  The furnace is only middle-tech --
it has a selectable speed (rather than continuously variable) blower.
But it does, I'm sure, have a lot more electronics in its controller
than did the 27-year-old unit it replaced.  I am suspicious that the
elex in the furnace is generating the QRM, but I have not tested the
hypothesis (have not even figured out how I could test).  OTOH, I also
fear that the problem is in my TS-850 itself, because turning down the
RF gain or turning on the front-end attenuators seems to make the QRM
go away.

Also, the new furnace is much louder than the old one.  It has
induction blowers and other air-moving stuff to make the combustion
more efficient.  I might have to get new high-performance
noise-cancelling headphones.  (I wonder if that cost would qualify for
the energy tax credit.)

73, Art K3KU
_______________________________________________
CQ-Contest mailing list
CQ-Contest at contesting.com
http://lists.contesting.com/mailman/listinfo/cq-contest



More information about the CQ-Contest mailing list