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| Courtesy: http://tomthompson.com/radio/projects.html |
Another type of noise problem was addressed in a posting to the topband reflector today by Don, WD8DSB.....the noise coming from a treadmill's, PWM speed-controlled DC motor.
" For many years my wife's treadmill caused strong interference on 160 meters when it was in use, and yesterday I was able to completely eliminate the RFI using a combination of two different filters (a commercial line filter that provides both common mode and differential mode filtering, and 14
turns of the power cord on a 2.4" OD Fair-Rite #31 mix toroid core based on
the K9YC hams guide to RFI document).
I created a simple website that documents my tests and the filters used,
and for those interested the website URL is:
http://sites.google.com/site/treadmillrfi/
The website contains a link to a video on youtube where you can actually
see the effectiveness of the filters. "
These two amateurs have developed slick solutions to their noise problems, but sadly, noise ingression is rising exponentially it seems and is becoming more and more challenging to mediate.
4 comments:
Thanks Steve --- Grow lights
are a big problem in BC (not just Colorado)!!
I like this reference too:
http://www.w0qe.com/RF_Interference/grow_light_electronic_ballasts.html
Thanks for the link Todd. Being illegal here still, maybe the easiest solution is to just call the cops. It's a problem that will only 'grow' it seems.
Just my .02$...
I think RFI is the number one threat to HF ham radio right now ! And I agree, it is exponential in growth ! The noise floor in my neighborhood grows every year, and this year I finally had to start using noise cancellation techniques to help mitigate it. A person starting out in HF, if confronted with the cacaphony of RFI now present, is likely to give up quickly. I do not know of any hams around here that do not have a noise issue of one sort or another. I don't know what the answer is, the IARU and ARRL seem powerless to do anything about it, and the FCC here not interested or able to enforce the EMI/RFI statutes on the manufacturers of all these electronic consumer goodies.
73 de Mark AB0CW in "the grow light capital of the world" Denver, Colorado
Thanks Mark...I agree. It is a hobby-killer and nobody cares. Here in Canada, AFAIK, anyone (consumer / ham) can file an official complaint with Industry Canada, if the noise coming from a Part15 device is exceeding it's limitations OR causing unwanted interference. They are bound, by legislation, to act on the complaint which would require the interference to the end user to cease. For 99% of these noisemakers, there is no problem since no hams are affected, so they are dealt with on an individual basis. Same with powerline noise.
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