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Re: [RFI] Unknown Signal

To: "Jim Brown" <jimbrown.enteract@rcn.com>, <RFI@contesting.com>
Subject: Re: [RFI] Unknown Signal
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Sun, 7 Dec 2003 13:56:52 -0500
List-post: <mailto:rfi@contesting.com>
> One of the strongest signals I hear is a pair at 14.030 and 14.031 MHz.
> They are pretty  constant carriers, and I strongly suspect they are
> local -- they are there regardless of band conditions.  About S6 on a
> dipole at 50 ft.  As I'm listening to it now, the carriers were just
> interrupted by a couple of short  bursts (1-2 seconds) of broadband
> noise.
> During the 160 contest this weekend, I observed a broadband hunk of
> trash (no carrier, just non-random noise) that is roughly 4 kHz wide
> centered near 1838.  It is also certainly ground wave.

Jim and all,

I'm 7 miles from the nearest two population centers of about 7000 people on
a remote dirt road in a large county of only 18,000 people.

When I shut off power to my house and look at my antennas with spectrum
analyzers, I can find hundreds of birdies from digital devices and SMPS
systems as far away as those two towns. Much of it is from my neighbors who
have electricity and modern devices like TV sets and computers, most of them
are still miles away. Some of it is 20dB out of my noise floor, even from
miles away.

Picture the odds of a problem in a large populated area of having multiple

There really isn't much enforcement anyplace in the system, and there is so
much stuff polluting the RF environment from the deregulated BC industry to
the consumer market that QRM is everywhere. The best thing I did was move to
the country, but even that isn't a total fix. The worse problems I have are
with AM and SW BC transmitters and Ham rigs that are nasty for spectral

I was using a new rig for the last several months and it took that long
before people actually told me my signal had a problem, so now I'm back to
my 10 year old FT1000D! Instead of someone telling me I had a radio
bandwidth problem, people would send insults on CW like "FU" or throw
carriers or send dots. Within hours of being told I had a problem, I located
it and found it to be a design shortfall in a brand new radio. That just
shows how little training we have at what should be acceptable, what isn't,
and how to deal with it.

We need some good RFI (including identifying problems with rigs) training,
and someone has to start holding manufacturers of consumer devices (our
radios included) to higher standards. I heard dozens of stations with
spurious emissions on 160 meters this weekend. IMO local RF devices are
second to our own radios.

This isn't going to get any better unless we push for higher standards and
more education.

73 Tom

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