[RFI] Can you identify this interference?

Mike A. King - KM0T scsueepe at mtcnet.net
Thu Jan 22 14:53:02 EST 2004

I did a little DFing during lunch today.  With my ICOM R10 handheld RX, the
signal peaked about 17.4 Mhz.   I suspected the transformer, cable boxes in
between my back yard and neighbors yard, however I always had also suspected
something from inside the neighbors house.

Well, with the IC-R10, the signal did not peak at the utiltiy boxes.
However, it did peak at the back end of my neighbors house.

Thank goodness shes a pretty nice old lady and works at the local gas
station down the street.

So, as mentioned before, I said this has been going on for 3 months or so, I
just never got around to it and suspected her house, so I never got bent out
of shape about it.

So at the gas station, we chatted and I asked her if she had added in the
last 3 or so months.....a scanner....no.....cable modem....no, any other
electronics, tvs, radios, clock radios, telephones...no....electric
blanket...no...BUT...oh in September I added an electric mattress pad for my
bed.  I asked is your bed at the end of the house by mine, yup.  Is the
thermostat like one of those that has the neat little orange neon lamp to
let you know its on...yup...

So, shes going to call tonight and "unplug" to verify as well as give me the
manufactures brand name, model, etc.

So, those of you on this reflector made me think to ask about electric
blanket / heating pads....I recall a story or two where I read here about
RFI from them.

Now, those of you in the know, what can I do about it?

Thanks and I will update for sure if this is the source.  Im 99.9% sure

Alex, ask around.  Perhaps you will get a bite!


Mike- KM0T

----- Original Message ----- 
From: "Alex" <kr1st at amsat.org>
To: <rfi at contesting.com>
Sent: Thursday, January 22, 2004 6:57 AM
Subject: [RFI] Can you identify this interference?

> Hi there,
> Since a few weeks I've been plagued with this pulsating type
> interference. I can receive the it from 12 MHz up to into the high VHF
> range. So far I've found one very wide peak around 19-20 MHz (S9). I can
> even see it on TV channel two (antenna, no cable) where it appears as 4
> or 5 squiggly lines. Here's a sound sample:
> http://www.kr1st.com/interf.wav
> And the image of the recording made by Audacity can be found at:
> http://www.kr1st.com/interf.gif
> The recording is made with the receiver on 28.4 MHz USB.
> Any suggestions are greatly appreciated.
> 73,
> --Alex KR1ST
> http://www.kr1st.com
> _______________________________________________
> RFI mailing list
> RFI at contesting.com
> http://lists.contesting.com/mailman/listinfo/rfi

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