Strange interference on 160

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  • Updated 2 years ago
Does anyone have an idea what this interference is from? It comes and goes on 160 at night, sometimes stronger sometimes weaker. Sometimes not there at all.


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W5UN_Dave

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Posted 2 years ago

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Kevin Va3KGS

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Morning David

Welcome to the world of the Spectrum Analizer !!  Do you see this noise pattern at the same location everyday, all day (Night Time)?  Do you see this pattern on any other band?  Check in your own home for things like Wall warts, battery charges.  You need to check your own home out by turning off breakers/fuses to eliminate your home. try a battery on your radio to eliminate power line noise. If you have a neighbour close by, then they may be generating the noise and its coming through the shared power line out on the street.  You may want to try another antenna to see if the noise level changes. HPS and those new fluorescent street lights are good generators of noise as well.

Hope a few of these pointers help in your quest.

Cheers

Kevin, Va3KGS

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Bill NE1B

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Good comments from Kevin.  I am assuming the interference you refer to is on the right side of the display, the wider QRM.   I found something similar coming from a small RV video monitor I use for my home security cameras.  At first I thought it was the wall wart.  Then removed that and hooked it up to a linear 12 v. supply.  It only went away when I completely removed power to it.  I also saw it QRM other bands, but not as noticeable, except on 6 meters where it slowly swept down in frequency. 
Happy hunting!
Bill, NE1B
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Barry N1EU

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Don't you mean the LEFT side of the display?
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Bill NE1B

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My mistake.  Poor resolution on my laptop here.  The RIGHT side looks like SSB.  I now see the vertical recurrence on the LEFT side.  Still a fox hunt.
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K1UO - Larry

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Looks like interference I would get thru my  HDMI cable when certain TV channels were selected .  Unplugged HDMI cables on the home entertainment system until I narrowed it down to the one coming out of the Sat Receiver.  Added a few snap on chokes and that was cured :-)
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Ken K7YR

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Hi Dave,

We get this type of interference quite often in the North Central Washington area.  I see on your picture that the frequency of the peaks are drifting slightly from higher to lower.  We are on 1963 most every morning between 05:30 and 07:00 Pacific time.  I have seen the exact "Stuff", however most of the time, while it is vary "Wide band" the small peaks, drift like sine waves are not synced, but move, usually from low to higher in frequency, hence, in addition to the visual account we have the sound like a rail road train going down the track, clickty-clackty-clickty-clackty, one of the guys says he think it sounds like an "Open Loop RTTY signal.  I can't go that far. The source is apparently not local as the members of the group are several hundred miles apart we note that the the interference seems to move around.  It is never strong, My noise floor here on 160 at that time is usually -110 ~ -112 dBm and the "Ripples" will peak up, maybe, 2 ~ 3 dBm higher than the noise floor then just fade away. Then they will "Snap" on then "snap" off.  My neighbor across the lake and about 4 miles away sometimes comments about hearing it, I don't, then five minutes later I hear it and he does not.  The only thing that I can suggest is that here it could be a ionospheric sounder, but who knows.

That's my story for what's it worth.  Flex radios are fun aren't they?  A lot of enjoyment is had viewing what is going around us.  The mysteries of the atmosphere and propagation!    

Ken K7YR  
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KY6LA - Howard, Elmer

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Here is what I am seeing at about 50 degrees azimuth from La Jolla CA



Taken remote from LAX

Looks like it's coming from Central Europe. Floats around 14,200

But also all over the bands
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KY6LA - Howard, Elmer

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It is very directional. And can be mulled by reversing the beam.

(Edited)