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48 kHz Wideband HF (WBHF), Chicago area HFT?

edited September 2020 in Signals Received
Interesting post over on Tony's blog:

I've added five known and/or suspected HFT transmitter sites in the Chicago and New York areas to the TDoA reference station list. I'd appreciate any additions/corrections, especially about corresponding locations in Europe.

Perhaps someone can do a little TDoA next time this signal pops up. A fascinating series of articles about shortwave-based HFT that I hadn't read before begins here:


  • I had a look at the signal Antonio refers to, and found it to be the same one I described on my blog a while ago. See TDoA and some unfinished attempts at bitstream analysis here and here.

    Having a quick look it's activity today I noticed 2 transmitters being active at the same time.
  • Thanks Christoph. I now remember reading your posts, but they didn't immediately come to mind this time around.
  • Within the HF industry, WBHF generally refers to that which is described here,, or another scheme developed in France. HFT, in which the words High Frequency refers to stock trading rather than radio, uses another scheme. In HFT, minimum trading latency is the goal and they use a unqiue scheme to minimum modem latency and thus trade latency. It is proprietary, so no details exist.
  • edited September 2020
    This contains info on Europe and other end points
  • jksjks
    edited September 2020
    @Jim: There was nothing on that entire website about coordinates of transmitter locations. Nor would I expect there to be. That's hugely sensitive information from their perspective.

    I'm looking for location details I can add to the TDoA reference station list. Mostly likely gathered by individuals snooping around as described in the second link I originally posted.

    Also, yes, I knew the dual-use of the HF acronym in this context. But others may have not. Too bad they didn't originally call it "HST" (high-speed trading). Although that sounds a little pedestrian. But that choice was probably made even before microwave links were the hot solution.
  • We've been discussing this over on the for a few years now, as some of their transmissions have impacted our listening pursuits due to interference, for example:,42596.0.html

    I think there's a link there to another article with some more info. IIRC one of the sites was in/near Aurora IL. They want to be fairly close to the Chicago Mercantile Exchange, as that's one of the trading centers.

    Also see these posts, and search for others on the HFU. One party has filed for a SWBC license (their existing Part 5 Experimental License is probably expiring so they have to go another route), they propose transmitting in DRM, presumably they will be stuffing the trading data in the digital stream.,69210.msg234838.html,69424.0.html
  • Okay, finally found it. I kept using a Kiwi with an excellent noise floor and along the great circle route. But it was under the takeoff angle I guess. It heard nothing compared to this one (1000 km further out). That's the CQ WW RTTY DX contest up the band.


  • Checking my overnight netSDR recordings on 43 meters, I see this signal was present, quite strong, starting around 0000z or a bit earlier. So it's likely strong on my KiwiSDRs as well, if anyone wants to use them for TDoA purposes. I have a fairly low noise floor here.
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