Help identifying noise

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  • Updated 5 years ago

Hi all,


Came home tonight to find the following noise started up on 75 meters. Was relatively quiet then BAM! Like someone threw a switch. I captured two screenshots. First is when it first happened then second is after it stabilized, but wider. Seems to go from around 2 to 5 MHz. The peaks are around every 15.5 kHz.


Thanks

Dave, wo2x




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David Decoons wo2x, Elmer

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Posted 5 years ago

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Bill Roberts

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I have a similar noise on 75 that started about 10 days ago. I've walked all over the house with a portable RX and no clues. No new appliances or lights around here. Bummer!
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Dudley - WA5QPZ

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Dave,

I would definitely tune around,  you might find the fundamental frequency and then go neighborhood hunting with a handheld radio.  

It could be a lose cable connection in a cable box to plasma TV going wild..  :-0      good luck.  

Dudley 
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Tim - W4TME, Customer Experience Manager

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Boy, that is U-G-L-Y. Tis the season for RFI.  The Xmas tree farm 400' due south of me opened for business tonight.  No more HF from sundown till midnight until Dec 25.
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Ken - NM9P

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That looks very much like the hash generated by the under-counter halogen lights at my place (powered by a wall-wart transformer).  These are notorious, especially if one of the bulbs develops a micro break in the filament that allows the light still to burn, but generates a nasty arc & spark type of interference.
It wipes out 160-10 with the most severe at low frequencies.

My XYL has been directed to leave it unplugged unless ABSOLUTELY necessary to use it.  

Another source of interference like it is generated whenever my neighbor returns from a camping trip and plugs his Camper trailer in to recharge the internal house batteries for a couple of days before it goes back into storage.  I just live with it.  The cost of having good neighbors.  (And he doesn't complain about all of my midnight antenna raising projects)  If you have a neighbor that has a camper or RV preparing for a trip or just returning from the same, it should disappear in a couple of days!

Ken - NM9P
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KY6LA - Howard, Elmer

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Or it could be a new Plasma TV in the neighborhood....

Time to borrow an RF Sniffer  - MFJ-852 is an OK one for finding strong signals like that
Or at least pointing you in the right direction
(Edited)
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James Kirk

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Grow lights for marijuana 
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Ken - NM9P

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Not an entirely unrealistic answer!  I have heard of that before.
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David Decoons wo2x, Elmer

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Just an update on the noise issue. It started on a Friday evening two weeks ago around 6:20 p.m. and was constant to around 10:45 p.m. Then it was gone! Has not happened since.

Glad it did go away.

Dave, wo2x