[RFI] Noise - where do I start?

[dalej]

Once I found a strange noise in my own house.  It was most noticeable on 75 meters because that was the band I used most often at that time.  It was purely random sparking sort of noise and strong so I knew it was close.  One day I had the radio audio turned up to listen to a conversation on 75 and as I walked though the kitchen I heard the random noise again.  Make a long story short I found in the basement the hanger wire for a drop ceiling was barely touching a conduit for electrical wiring and when I walked on the floor upstairs it created enough vibration to cause the noise from that contact.  Weird things with finding noise.  I also in the past disconnected completely the old door bell transformer which was in the basement too.  Those things can be noise makers.  

Dale, k9vuj


On 26, Sep 2016, at 8:49, Patrick Dyer <pjdyer at swbell.net> wrote:

To reinforce the "check-home-first" strategy a slightly-embarrassing tale from here in late December 2012.

I suddenly had a very strong "hung-arc" noise thru 144-MHz one morning that sounded like the return of some never-located RFI from early 2008.

So with that in mind I got the 4-el 2-m RDF Yagi (part of an old 11-e Cushcraft) connected to my IC-4A (which goes to 136-MHz) and took some bearings.

It didn't peak west (where the 2008 RFI had), but after several bearings made in the front and back yards it seemed to be coming from my house.  I pulled the main breaker and it quit.  Then it was on the individual circuit breakers.

That isolated it to the lines feeding the "radio room" itself.  With some fear that it might be some in-wall wiring problem (place was built in 1971) I started turning off equipment.  I finally touched an antenna rotator box (for TV-FM antennas) and it quit.  This had all taken the better part of an hour to locate an RFI source that was literally only inches from my face!
http://www.qsl.net/w/wa5iyx/fmdx2012.htm (near bottom).

Pat - WA5IYX
http://www.qsl.net/wa5iyx/index.html

On 9/26/2016 04:57, James Gordon Beattie, Jr. wrote:
> Ed,
> 
> Bravo!
> 
> 
> That is why I started with the recommendation that you cut the power to your own house first and run your radio on a battery as you bring up circuits one at a time to take measurements.  Taking detailed notes on the observations of signals both home, and eventually if you end up going around the neighborhood, is also key.
> 
> 
> There have been a lot of other good suggestions, but doing the basics are essential for the reasons you provided.
> 
> 73,
> 
> Gordon Beattie, W2TTT
> 
> 201.314.694
> 
> 
> 
> Sent from AT&T Mail on Android
> 
> 

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