[Elecraft] QRM and filtering

[Lou Kolb]

I had a nasty noise of s9 plus for a week or so.  Finally tracked it down to 
the wall wart on my XYL's sling box.  It had been there for years but I'd 
noticed it had always been warmer than most of them although it seemed to 
work okay.  Apparently, it must've gone bad and started generating a 
terrible hash.  When I pulled it the problem was immediately solved.  73, 
Lou WA3MIX
----- Original Message ----- 
From: "Ron D'Eau Claire" <ron at cobi.biz>
To: "'Mike Weir'" <ve3wdm at hotmail.com>; <elecraft at mailman.qth.net>
Sent: Friday, October 22, 2010 5:10 PM
Subject: Re: [Elecraft] QRM and filtering


> That sounds like arcing somewhere Mike (BTW, it's QRN - N - noise instead 
> of
> QRM -M for interference from other stations).
>
> It could be a power line insulator. Sometimes a fluorescent bulb dying
> sounds like that as the starter keeps re-engaging. I've heard that sort of
> thing from some street lights that are flickering. Sodium lamps generally
> create hash, but ordinary incandescent bulbs, in a street light or 
> somewhere
> in the house, can do exactly the same (their filaments sometimes fail but
> are still touching and there is intermittent arcing across the opening).
>
> Unfortunately the possibilities are as endless as the number of places 
> there
> might be something arcing over.
>
> How's the weather been? The advent of the rainy season sometimes causes
> dirty power line insulators to arc. When it rains enough it may wash the
> dirt off the insulator it may stop all by itself.
>
> I'd tackle it like others have chased RFI here: start switching off 
> circuits
> throughout the house while listening. If it stops, you are in luck - it's
> something under your control in the circuit you shut down.
>
> If not, you'll need to start hunting with a portable radio. Follow the
> strongest signal along the power lines. At that point you can start to
> enlist the help of your power company. Cooperation varies a lot, but some
> are extremely helpful.
>
> One time I was bedeviled with noise like that and couldn't track it down. 
> It
> was emanating from the general area of several blocks in the neighborhood.
> Then, one night after dark, I noticed something while taking a walk. A
> intermittent weak flashing on one of the power poles. And there it was - a
> dirty insulator arcing over. The utility came out within a couple of days
> and hosed down all the insulators in the neighborhood!
>
> Ron AC7AC
>
> -----Original Message-----
>
> Over the last 2 weeks some QRM has shown up and I have tried some of the 
> NR
> and NB filtering options to get rid of it and it's not really working to
> well. I am not sure if I am using the proper filtering or the settings I 
> am
> using are off. I have an audio example of the QRM or even RFI on my blog
> site. The link is below I feel if you listen to it that may help.
> Mike
> http://ve3wdm.blogspot.com
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html