[Elecraft] OT: RF interference from grow lights.

[RALPH TURK]

Hi
I had a similar situation here in Tucson AZ  My spectrum analyzer,a Tek 492 showed groups of carrier like indications 10-20 db above the noise floor.  First think I thought "Grow Lights"  I was told that the osculator in a grow light is about 2.3 Mhz.  The interference looked like it was every 2.3Mhz up the band.  Levels were all over the place.  Called the local Power Co and after lots of pleading they finally sent a tech to check it out.  He connected up to my dipole antenna and looked at the pattern and concluded it was a ground connection proble.  Got a crew out the next week and traced it to a pole out about 2000ft from me.  The problem was radiating 
from the HV line for about 2 miles.  Fixed the ground and problem
solved.  I had traced to one of three poles using a portable radio tuned the my main problem freq of about 5.2 Mhz and was able to hear the problem.  The main problem was a loose ground clamp up on the pole.  The power company also used an acoustic parabolic mike which pin-pointed the exact connector.  New connector problem solved
Ralph, W7HSG/AFA9RT
 
> On 08/20/2020 7:07 PM ab2tc <ab2tc at arrl.net> wrote:
> 
>  
> Hello all,
> 
> https://www.edn.com/how-cops-are-finding-grow-ops-with-am-radios/
> 
> The above is a link to an article in the EDN magazine (a technical journal
> primarily aimed at EEs). The article is more than five years old, but maybe
> it is only recently this type of interference has started to show up in
> upstate New York. I have one of these noise sources somewhere in my
> neighborhood (it’s not that easy to pinpoint due to the low frequency). I
> know this is OT and maybe somewhat controversial, but this type of strong
> interference is of great concern to the amateur radio community. I am not
> after anybody in my neighborhood getting arrested, but I very much want to
> see the interference stop. Even if the operation is legal, the emission is
> definitely way outside FCC part 15 limits. Quote from the article:
> 
> “..conducted emission data clearly shows peaks as high as 100+ dBuV (50 dB
> over the limit) in the range 6 to 8 MHz, with lower peaks at 14, 18, and 21
> MHz.”
> 
> My interference is primarily in the 7MHz band. 14 MHz is virtually free of
> it. See here for a screenshot:
> 
> http://www.ab2tc.com/growlights.png
> 
> There are three peaks, approximately 49 to 50kHz apart. The center one is
> centered under the cross hair cursor. As you can see, the band is starting
> to come to life at about 2:30 in the afternoon. The interference is on 24/7
> as far as I can tell.
> 
> Does anybody have any experiences like this and/or any suggestions what to
> do? If you want to keep this confidential, E-mail me privately. My E-mail
> address is OK on qrz.com.
> 
> AB2TC – Knut
> 
> PS. I have previously reported power line noise to the electrical company
> and have had positive responses (fixes) from them. I suspect that this kind
> of interference is not easily detectable on their UHF based sniffers;
> besides I am not sure if conducted interference from residences lies under
> their jurisdiction (there are only residences here for many blocks).
> 
> 
> 
> 
> 
> --
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