[Elecraft] Strange RFI question

[Fred Jensen]

Slava,

I can't make the link work but regularly spaced  signals are a classic 
sign of a Switched Mode Power Supply [SMPS].  I host the local wireless 
company's RAP for our neighborhood on my tower, in return we get the 
backhaul speed [17 Mbps] for free ... yes, we power it.  Really great 
for Andrea's Netflix addiction.  They recently replaced the gear, and it 
is now powered by a UPS in our shed with an SMPS with raucous noise 
peaks every 26 KHz +/-, they move around a bit.  Since the wireless 
company seems to be preoccupied with getting new customers, I'm going to 
wind a couple of toroid chokes and see if I can fix this.

Wall warts are in most cases these days SMPS.  So are LED lamp power 
supplies.  I'll send you a screen shot of mine if you'd like, their UPS 
is connected to a cable to the top of the tower and down to the router 
at the bottom ... resembles a 160 Inv-L.

73,

Fred K6DGW
- Northern California Contest Club
- CU in the 2014 Cal QSO Party 4-5 Oct 2014
- www.cqp.org

On 4/8/2014 6:34 PM, Slava Baytalskiy wrote:
> Hello everyone!
> I'm not sure if this is the correct forum for this sort of a question but i figured i'd give it a shot.
> I've been going out of my mind with this strange signal pattern i've been seeing on my new panadapter connected to my new K3.
> I first saw it on 20 meters. It seems to be the same signal pattern, spaced evenly, at 61 kHz intervals.
> Something tells me that it could very well be outside of my shack. I've got the street power lines 15 feet in front of my house, with a big transformer on top of a pole.
> I just took a video of the whole thing and you can also hear the sound of it, especially while i tune it up and down.
> Here's a link to the video file in my DropBox: https://dl.dropboxusercontent.com/u/111549/rfi/strange_rfi.wmv
> Sorry for the format. This screen capture program only does Windows Media Video.
>
> I've gone to a point where i've disconnected everything in the shack. Literally. And i could still hear it.
> My Yaesu 857D also hears it, with the same antenna hooked up to it, so that tells me its not my K3 or the panadapter (for that matter).
> I also tried hooking up another antenna (i have a home made fan dipole) and i can still hear it. So its not the antenna (right?).
>
> I'm very open to any suggestions as to what to do? How to narrow it down?
>
> Thanks a bunch in advance!
>
> Slava, W2RMS
>
> P.S. I almost wish i didn't have the panadapter, so i wouldn't even know its there... :-(
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