UNID Digital mode? Noise? on 7570 kHz (WRMI TX 11) 0527 UTC 18 July 2023

[nitroengine]

Hopefully this is the right place to post this.


I spotted this on my KiwiSDR as well as a few other KiwiSDRs I checked (so it's not local noise).

7570 kHz while The Overcomer Ministry is scheduled to be broadcasting on WRMI (transmitter 11). First noticed it at about 05:27 utc.

The signal dropped out at about 05:32:08 utc and came back at 05:33:54 utc, then dropped back out a few seconds later. Looked to be about ±12kHz wide.


IQ Recording ±10.125k BW

[~SIGINT~]

These are presumed to be associated with High Frequency Trading (HFT) activities. I refer to these as "The Swath" or "Energy Swath" and are just terms that I coined to describe it.

Myself and others have documented a few of these over the years on the HFU.

The Swath 7880 (C) 0028 UTC 19 DEC 2022
https://www.hfunderground.com/board/index.php/topic,106992.msg335708.html#msg335708

UNID 6940.0 kHz (Centre Frequency) 00:00 UTC 01 FEBRUARY 2022
https://www.hfunderground.com/board/index.php/topic,92398.msg295091.html#msg295091

If you use the "search" feature on the board and enter HFT or High Frequency Trading you should find the posts.

[nitroengine]

Thanks. Seems plausible that is what the signal could be.

I've heard hams complain about HF traders taking over spectrum and often stepping on other signals. There has also been some talk about the Kiwi network being used by HF traders to analyze conditions (at great disapproval by the developer of the Kiwi).

According to short-wave.info, WRMI should've been on the air with Brother Stair (or Brother "Scare" as some folks call him). So I wasn't sure if it was something going on at WRMI or what. Although, I know there has been some speculation that WINB has been using half of their spectrum while running DRM to provide data services to HF traders.

However, I just checked WRMI's actual schedule and it shows their transmitter 11 is only on the air at that time on the weekends.

[~SIGINT~]

... some talk about the Kiwi network being used by HF traders to analyze conditions (at great disapproval by the developer of the Kiwi)

I had not heard of this but is very plausible and it would not surprise me one bit. HFT providers are currently lobbying the FCC to change their license from "experimental" to a full license stating that FCC rules governing HF are archaic.

There is a bit of a thread on the HFU with regards to the petition:
Market Makers” Want to Expand Their Use of Shortwave?
https://www.hfunderground.com/board/index.php/topic,115893.0.html

Although, I know there has been some speculation that WINB has been using half of their spectrum while running DRM to provide data services to HF traders.

That should be a breach of licensing and an immediate cause for a license suspension. If it is commercial data for revenue purposes and furthermore is encrypted it is game over, full stop. I hope someone is monitoring this.

[nitroengine]

Here's WINB's "DRM" signal. Only the upper sideband is DRM, the lower sideband is unspecified proprietary digital data (which some speculate is HFT data). Not sure how they convinced the FCC to allow that.



Some talk about WINB and their DRM and thoughts about this mystery digital data they are running:
https://www.drmrx.org/forum/showthread.php?t=2800&page=3
https://forum.kiwisdr.com/index.php?p=/discussion/1865/drm-heard/p5


Also, here's some talk about the Kiwis possibly being used by HF traders:
https://forum.kiwisdr.com/index.php?p=/discussion/2903/re-all-those-90-sec-wf-only-connections

[~SIGINT~]

I have had this discussion with someone else and have been told that this is not data. It is a residual effect of DRM when only transmitted on a single SSB. I have heard the same speculations that WINB wanted to use the LSB for HFT data but cannot due to regulations. An HF broadcast license will not permit this kind of operation.

I have seen this recently as well. Below is a June 2023 capture on 15720.0 kHz.

[nitroengine]

I did read somewhere where WINB confirmed the modulation in the lower sideband as being digital data (just not what the data is for). I'll try to see if I can find that, it's been awhile since I last researched it.

[nitroengine]

I believe this is the page I'm thinking of: http://i56578-swl.blogspot.com/2018/08/winb-red-lion-to-test-drm-single.html

I originally thought it was just a mode of DRM they were using and didn't think into it too much until I saw folks throwing around the possible use HF trading with the controversy that goes along with it.

[~SIGINT~]

Thank you for the link. I follow Antonio's work regularly. Interesting enough, there has been no update on the subject since November 2018. After nearly 5 years of testing and no recent reports one must assume that there is nothing significant on the LSB.

In my opinion DRM on HF is junk. The only worthwhile transmissions which I have enjoyed listening to were the Brazil DRM Experimental transmissions of February 2021. Despite employing the full 10 kHz of channel bandwidth, the audio was streaming in AAC+ format at 12.46 kbps and unfortunately still sounded like a low bit rate MP3. Still, those transmissions are the best DRM ones that I have heard so far.

Experimental DRM station in Brazil, 11910 kHz, 09 JAN 2020, 2313 UTC
https://www.hfunderground.com/board/index.php/topic,76670.msg255323.html#msg255323

WINB DRM Schedule:
https://www.short-wave.info/index.php?station=WINB%20DRM