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[RFI] Noise is everywhere (was Solar Arrays)

To: rfi@contesting.com
Subject: [RFI] Noise is everywhere (was Solar Arrays)
From: "Frank N. Haas" <kb4t@arrl.net>
Date: Thu, 10 May 2007 04:33:46 +0000
List-post: <mailto:rfi@contesting.com>
Take any portable AM/FM/SW receiver, tune it to a fairly quiet spot on the 
AM Broadcast band and pass it near any microprocessor-equipped device, 
vacuum flourescent digital display-equipped device or virtually any 
consumer electronic battery charger or electronic device with a switching 
power supply. Take a walk through the kitchen, laundry room, past the 
digital thermostat, the big new TV and both of your computers.

Invariably you will hear a cacophony of noises, buzzes, hums and whistles 
that will make your skin crawl.

For the most part, you can thank the folks who design and build the wide 
variety of consumer electronic switching power supplies. In the last year I 
have found 2 mobility scooters with switching power supplies running their 
internal chargers that blot out 7, 10 and 14 MHz nicely. I have found 2 
cordless phone battery chargers that put lines on Channel 9 television. At 
least 5 larger style battery chargers ( for charging marine batteries and 
such) that make great 1-28 MHz QRM generators. Big switching power supplies 
for an elevator controller, one satellite dish switching power supply, a 
no-name DVD/VHS tape player, several photocells.....  the list is endless.

To save pennies and improve the bottom line, RFI suppression parts are 
being left out of just about everything sold by big box movers. The RF 
pollution is incredible. Enforcement has been non-existent for decades. We 
are reaping what we have sown. Moving manufacturing offshore has reduced 
cost (and many jobs) but it has also eliminated quality control, 
enforcement or implementation of basic design standards that limit RFI and 
made those of us who want to use the HF spectrum long for 5 or 10 acres in 
the wilderness. The big winners are the folks laughing all the way to the 
bank and the folks who make ferrite donuts. ( I just bought 24 2.5 inch 
type 31 ferrite cores and it cost me nearly $300! $11.65 each plus 
shipping! ! ! )

One of the things that hams must do now is watch very carefully what they 
plug in inside their homes. They must develop good working relationships 
with neighbors in order to more easily sell the idea that a power cord 
wound around a couple of big ferrite donuts will not hurt anything.

It is likely that we will never see a return to RFI-suppressive designs and 
enforcement of any standards. Money speaks louder than the minority who are 
affected. For RFI snoops like me, it means job security. For all of us who 
cherish the HF spectrum, it means a never ending and un-winnable war 
against an epidemic that can no longer be stopped. Start looking for your 
home in the wilderness if you want peace and quiet.


Frank Haas KB4T
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