HFU HF Underground

General Category => General Radio Discussion => Topic started by: ultravista on March 17, 2019, 1535 UTC

Title: QRM Question ~ 15000 KHZ to 50000 KHZ
Post by: ultravista on March 17, 2019, 1535 UTC

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 Tokens Southern California SDR
https://imgur.com/rJeESnw

Title: Re: QRM Question ~ 15000 KHZ to 50000 KHZ
Post by: Josh on March 17, 2019, 1758 UTC

Are you all running the same sdr with spurs on the same freqs? Does the noise go away with propagation?
That looks kinda strong to be spread all over the southwest like that and not be locally generated. Also, if you're brave enough to have java installed, try to tdoa the sigs and see where they come from.