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Author Topic: HF UNID, 4476KHz center, 1432khz BW from 3760 to 5192KHz, 4khz carrier spacing  (Read 2409 times)

Offline Monophonia

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A very wide discernable signal on the waterfall, with "carriers" every 4Khz.
First carrier at 3760KHz last carrier at 5192Khz
13:46UTC 8/4/22 ongoing
Bursts up to 18 seconds long, some as short as 2 seconds long, the transmissions are occurring no more than 20 seconds apart.

I have a recording taken in IQ mode centered on the first carrier, some screenshots of the waterfall showing the definition of the signal.

Receiver is my own KIWI SDR and 160M inverted V in Ohio.



Offline Monophonia

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Bumping this since It's still on my mind, and it's still persistent in the same spot with the same intervals.

Best observed to my knowledge on this kiwi: http://nd8dkiwi.ddns.net/

Offline Shortwave_Listener

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That is really bad local RFI (interference).
Lucas Bandura
eQSL appreciated! lucasnerite@gmail.com
Songs are identified with Shazam if needed. I usually use KiwiSDR receivers. Reception from my QTH is using an SDRPlay RSP1A for SWL with a 40 meter band Inverted V at 40 feet. Kenwood TS-570D for ham use.
My website: https://swl7.wordpress.com/
Shortwave Radio Archive: https://www.youtube.com/@SW_Archive
https://archive.org/details/@shortwave_radio_archive

Offline Monophonia

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That is really bad local RFI (interference).

Well, I was able to verify that whatever it is, it's not local. We had an area power outage and it is as strong as ever using the IC-705.

When I get my noise flag from DXE I'll see if I can take a direction on it.

Offline Shortwave_Listener

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That is really bad local RFI (interference).

Well, I was able to verify that whatever it is, it's not local. We had an area power outage and it is as strong as ever using the IC-705.

When I get my noise flag from DXE I'll see if I can take a direction on it.

A power outage doesn’t always eliminate local QRM. For example, it could be a device in a home with a generator.
Lucas Bandura
eQSL appreciated! lucasnerite@gmail.com
Songs are identified with Shazam if needed. I usually use KiwiSDR receivers. Reception from my QTH is using an SDRPlay RSP1A for SWL with a 40 meter band Inverted V at 40 feet. Kenwood TS-570D for ham use.
My website: https://swl7.wordpress.com/
Shortwave Radio Archive: https://www.youtube.com/@SW_Archive
https://archive.org/details/@shortwave_radio_archive

Offline Monophonia

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That is really bad local RFI (interference).

Well, I was able to verify that whatever it is, it's not local. We had an area power outage and it is as strong as ever using the IC-705.

When I get my noise flag from DXE I'll see if I can take a direction on it.

A power outage doesn’t always eliminate local QRM. For example, it could be a device in a home with a generator.

I don't think I defined local well enough, in this case myself and the immediate neighbors (300 yard radius). Nobody in that radius has an automatic standby generator so there is a fairly reliable period of outage before everyone hauls out their portables. And since it was mid-day with many at work, I don't think anybody actually started their sets.

I've done a fair bit of RFI hunting, this one just still has too many signal qualities for me to write it off as noise just yet hence the inquiry. Though reality often points to the boring answer.

Offline Shortwave_Listener

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Have you checked any other nearby KiwiSDRs? If it is something that is not local it should be observable on another KiwiSDR in your general region.
Lucas Bandura
eQSL appreciated! lucasnerite@gmail.com
Songs are identified with Shazam if needed. I usually use KiwiSDR receivers. Reception from my QTH is using an SDRPlay RSP1A for SWL with a 40 meter band Inverted V at 40 feet. Kenwood TS-570D for ham use.
My website: https://swl7.wordpress.com/
Shortwave Radio Archive: https://www.youtube.com/@SW_Archive
https://archive.org/details/@shortwave_radio_archive

Offline Monophonia

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The nearest public Kiwi is swamped in it's own broadband QRM in that bit of spectrum.

 The rest of the mapped kiwis are 60+ miles away, no discernable signal on them.

I did get a bearing on it with my flag antenna, The strong null points off into empty field, by the map the nearest structure is over half a mile away. If the weather clears and I get the farm chores done I'll do a bit of driving and see if I can get additional bearings.

 

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