QRM Question ~ 15000 KHZ to 50000 KHZ

[ultravista]

I am in Southern Nevada and finding QRM spikes on my SDR that are also present on other SDRs in area (Southern California, etc). I am can see these noise signatures above 15000 KHZ spaced somewhat evenly all the way through 50000 KHZ.

When tuned in AM, it is like a rushing sound - every one sounds the same. The QRM is always present across multiple antennas and geographically distant SDRs.

I see the same QRM on a California SDR at exactly the same frequency. It appears day and night.

I would like to know the source of this QRM. Perhaps a natural source?

Broad view from my SDR

https://imgur.com/RYCFVpK

Close view from my SDR

https://imgur.com/J6Cqezs

Close view from a Southern California SDR

https://imgur.com/rJeESnw

 

[RFI-EMI-GUY]

switching power supply?

 

[prcguy]

Could be. Try to measure the lowest related pip you can find, then measure several in a row and see if they all have the same spacing between them. If so, that could be a switching power supply and its harmonics.

If it were AM BCB overload and resulting Intermod you would generally see many copies of a modulated AM station spread up the band where they don't belong and you would hear some of the station audio when tuning them in.

switching power supply?

 

[ultravista]

The same QRM is present in a SDR that is at least 150 miles away - spot on @ the same frequency spaced from 15000 to 50000. It can't be a switching PS ...

 

[majoco]

Broadband over power lines?

 

[Boombox]

Perhaps the remote SDR also has a switching power supply nearby? Switching power supplies are fairly common.

 

[slicerwizard]

Looks like what you get with a typical cheap SDR - internal noise...

 

[KB4MSZ]

Try reducing your gain

 

[ultravista]

Looks like what you get with a typical cheap SDR - internal noise...

I am using a Yaesu FT-950 and RSP2 as a panadapter. Not the typical cheap SDR. The other SDR I referenced is in Southern California and a Kiwi SDR, not a cheapie either.

 

[zz0468]

The same QRM is present in a SDR that is at least 150 miles away - spot on @ the same frequency spaced from 15000 to 50000. It can't be a switching PS ...

I'm in southern California, and I don't see anything at all like that, so it's unlikely to be a wide-area phenomenon.

 

[ultravista]

Here's one: http://tokenradio.proxy.kiwisdr.com:8073/

Tune to 16594.40. You'll see it elsewhere too.

 

[majoco]

All I hear is a bit of high speed RTTY or similar.