|[AMRadio] Buzzies and hash all over the spectrum|
bguyger at sbcglobal.net
Tue Mar 16 16:23:36 EDT 2010
The noise floor in my neighborhood is thru the roof because of all the switching power supplies and compact fluorescent lights. It sucks, but that's just the way it is. I also live 3 blocks from the Dallas Area Rapid Transit light rail line which is powered by a monster switcher.
Steve's paper is good stuff, he put a lot of work into it, but also please see the paper by Chuck W1HIS
A lot of it is Common Mode Chokes for Antennas, but he spends discusses getting rid of interference from computer power supplies etc. with ferrite common mode chokes
Chuck is a big time contester and DX'er and also happens to be a Radio and Radar Astronimer and is Professor Emerius of Planetary Studies at MIT. He also holds several of the patents that make GPS work. SOB may know what he's talking about. He also has a really neat design for what he calls a Sloper Doublet that covers all the HF bands. I can send you some poop on it if anyone is interested.
From: Rob Atkinson <ranchorobbo at gmail.com>
To: Discussion of AM Radio in the Amateur Service <amradio at mailman.qth.net>
Sent: Tue, March 16, 2010 10:44:01 AM
Subject: Re: [AMRadio] Buzzies and hash all over the spectrum
I have been saying for the past six months or so that about the only
solution to the appliance RFI problem is every man for himself, i.e.
put up a low noise rx antenna, employ a phase shifting nulling box on
receive, and forget QRP or even 100 w. Everyone has to raise the
desired signal level by running legal limit. The unintended
consequence of the FCC blowing off their duty to enforce RFI
suppression in consumer products is simply that everyone will start
running a lot more power on transmit to get over the high noise floor.
If that causes more RFI _to_ part 15 devices too bad for them. FCC
should have thought of this before they let big product manufacturers
and vendors have their way. This QRM has to be dealt with the same
way SSB QRM is dealt with--more power, bigger antennas, more audio.
On Tue, Mar 16, 2010 at 10:04 AM, <sbjohnston at aol.com> wrote:
> Don wrote:
>>I'm far more concerned about all the consumer crap on the market
> to-day that
>>dumps buzzies and hash all over the HF spectrum, with apparent
> impunity .
> This as a VERY serious problem for all radio users - there seems to no
> longer be any interest in control of incidental RF radiators. For
> example, when I got an FCC field engineer to come out and test some
> noisy LED traffic signal systems, he said (paraphrasing), "Yes, I can
> see none of these are meeting Part 15 requirements, but hey, people can
> just listen to the stronger signals that get over the noise." And
> shrugged and went back to the office.
> I did a study of the noise problems for FM broadcast reception due to
> locally-generated noise. You guys might find it interesting as it
> really applies to the whole spectrum (I just needed to focus on our
> industry in particular). I've posted a copy of the resulting paper on
> my website at
> Steve WD8DAS
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