Strange data (?) signal on 6860 kHz

[WA4FHY]

I usually park on 6925 kHz if I'm not doing anything else; one afternoon last year,
just before Thanksgiving, I started seeing a strong carrier on 6860 kHz. It was of
interest because it was much stronger than any other signals in that part of the band -
 see screenshot below (I hope!). The signal would come on near local sunrise, NOT fade
in but as if someone flipped a switch; it was of more or less stable strength until around
sunset when it would go away just as it appeared in the morning - as if someone
flipped a switch off. One day I decided to see if it was a real signal: 1) fired up the trusty
ol' R-70 and yes, it was there, 2) I logged onto several remote SDRs, from the Northeast to
Point Reyes, with a stop at the Northern Utah SDR - it could be received on all of them. 




Shortly after the first of this year, I noticed a change - I could see what looked like modulation
that seemed to be near random bursts of data. See image below. Also, it did not show up
as regular as in the past.


More recently, it has changed again - the carrier is gone, only the random data bursts
show up! See image below.


This has my curiosity; I have no idea what this is. Any thoughts on this anyone???

10may21 - Looks like the same, or similar, station is using 6885 kHz this morning.

19sep21 - This, or similar, station is now sometimes on 6860 kHz, 6885 kHz, or 6988 kHz
                 Seems to change with time of day. Also, "data bursts" are not as wide as originally seen

 

[BoomboxDX]

I heard the carrier earlier this morning (Sept. 15, 2025) on 6988 kHz between 1135 UTC (when I tuned in) until 1150 UTC when it switched off. It was weak, under S1 in signal strength, and had a polar flutter to it.

This was on my Tecsun PL-330 and an 8 meter indoor wire, and I'm in the PNW US.

I suppose I'll have to monitor this frequency more often.

[BoomboxDX]

I heard the signal again early this a.m., Pacific time (Sept 16th, UTC), from tune in at 1229 UTC until it cut off completely at 1309 UTC, which was 6:09 a.m. Pacific Time. Frequency was 6988 kHz. The signal seemed to increase in strength from 1229 to 1300 or so, from around S1 out of 5 to S3 out of 5, before seeming to dip again right before cut off.

The signal also -- just like last time -- had what sounded like a polar flutter or fast fade to it, maybe 6-10 fades per second. Cut off was the same as I described and WA4FHY has described. Like flipping a switch.

Unfortunately, neither time I've heard this carrier have conditions or activity on 40M been good enough to judge the 6988 kHz signal against anything else. Both times I did NOT hear the Petropavlovsk 'K' beacon on 7039, which usually is a pretty good beacon to N Asia and the N Pacific. But, as we all know, prop can vary from region to region. Still, this signal stuck out when there was no DX activity, to speak of, in the lower reaches of the 40M band (CW was dead).

Being that this signal is a bit erratic, and that the increase in signal might have been due to a grey line effect (indicating it might be in the US), I wonder if this is a pirate signal of some sort. Especially considering the proximity to the pirate radio frequencies.

Just throwing that out there. At this point, I have no idea what the signal may be.

This time I tuned it in on my DX-394, using my indoor wire.

[BoomboxDX]

I heard a similar carrier on a different frequency this a.m., on 6938, tuning in at 0525 UTC. It varied in strength from S1- to S2+, peaking around S4 around 0600 or so, probably a short, strong fadeup.

It was still on when I checked it later, around 1135 UTC (0435 a.m. Pacific Time). Next time I checked my DX-394, at around 1300 UTC, it was off.

Once again, there was little to zero activity on 40M to compare it with. The Petropavlovsk 'K' beacon was in with some moderately strong signals, on 7039. The San Francisco ACARS / HFDL digital bursts and beeps were blasting away on 6559 kHz. But nothing else, really, to compare this unid. signal with. The unid. Stanag transmission on 6843 kHz was no help, really, as no one seems to know where that is located. NAU's FSK was loud out of Puerto Rico on 6487.

Of course, if this unid carrier is low power, comparing it to other known stations really is an exercise in futility.

[BoomboxDX]

Lately I've logged these mystery carriers on 6988, 6938, 7000, and 6979 (0908 UTC, 3 Nov). On at least one night (0709 UTC 31 Oct) I noticed two carriers, one on 7000 kHz and another on 6938 kHz, both at roughly the same strength.

Just three hours ago (0951 UTC, 5 Nov) I logged one on 6900. Being that the remainder of the 40M spectrum was basically dead (i.e., nothing out of Japan, 'K' beacon from Petropavlovsk missing), I still think the mystery carrier was somewhere in the Western US.

The carriers seem similar, but then again, a carrier is a carrier, right? So it's possible they have no connection. That said, they seem to appear during the same hours, and have no other components, at least that I've heard (the OP's noticing data bursts notwithstanding).

I've noticed these dead carriers always having the same general strength from night to night, depending on the general propagation for the band. It reinforces my guess that they are from the western US somewhere, as the propagation from these carriers doesn't seem to match anything coming out of Asia or Siberia, unless the carriers are super high powered.

[Token]

Shortly after the first of this year, I noticed a change - I could see what looked like modulation
that seemed to be near random bursts of data. See image below. Also, it did not show up
as regular as in the past.

This signal is an HFT (High Frequency Trading) related waveform.  Yes, I know, everything gets blamed on HFT.  But, this one specifically is license holder WP2XCZ, RCA Telecom LLC.

The signal should come up on frequency with a Morse ID at the beginning of each transmission, and then ID, with Morse, every 20 or 30 minutes after that.  WP2XCZ (and several other HFT experimenters) started IDing late last year, after they lost an FCC granted "ID exemption" that they had been operating under for some time.

T!

[BoomboxDX]

Shortly after the first of this year, I noticed a change - I could see what looked like modulation
that seemed to be near random bursts of data. See image below. Also, it did not show up
as regular as in the past.

This signal is an HFT (High Frequency Trading) related waveform.  Yes, I know, everything gets blamed on HFT.  But, this one specifically is license holder WP2XCZ, RCA Telecom LLC.

The signal should come up on frequency with a Morse ID at the beginning of each transmission, and then ID, with Morse, every 20 or 30 minutes after that.  WP2XCZ (and several other HFT experimenters) started IDing late last year, after they lost an FCC granted "ID exemption" that they had been operating under for some time.

T!

Just curious, to your knowledge do these HFT transmitters run dead carriers when not sending data? I've heard of some transmitters in the Ute spectrum transmitting dead carriers as a sort of guard frequency. Would these HFT stations do the same thing?

I haven't yet read that HFT stations send dead carriers when not transmitting data.

Also, are most of these HFT data transmitters in the Midwest? If so, they must be putting out the watts to slam a PL-330 on an indoor antenna here in WA state where I live.

[Token]

Just curious, to your knowledge do these HFT transmitters run dead carriers when not sending data? I've heard of some transmitters in the Ute spectrum transmitting dead carriers as a sort of guard frequency. Would these HFT stations do the same thing?

I haven't yet read that HFT stations send dead carriers when not transmitting data.

Also, are most of these HFT data transmitters in the Midwest? If so, they must be putting out the watts to slam a PL-330 on an indoor antenna here in WA state where I live.

I do not know, first hand, anything about these stations.  But I have intentionally observed them quite a bit.  So my understanding is strictly limited to what I have seen.

In general, I have not seen HFT stations use a dead carrier when not sending data.  The exception to that is this particular station / format in this thread.  The carrier with wideband pips / PSK data every second or so.  On several occasions I have seen it be a dead carrier for extended periods, either after a period of the pips or before the data starts.

The "center" of the HFT stuff seems to be in the Chicago area, however there are also sources in Europe, as well as the PNW (Washington, licensees such as this specific signal in this thread, WP2XCZ, Ritzville, WA) and in Canada.  I believe there are some stations in the Northeast also, NY / MA area, but I have not yet tied those to a specific license.

As for them running some power, yes, they do.  According to their license information, this particular station has an ERP, on this frequency, of over 400 kW, and some frequencies are more like 900 kW (TX power is 16 kW).

T!

[BoomboxDX]

Interesting info. If the transmitter on 6838 is the one in Ritzville, I'm wondering what region it serves. My guess is Japan? The PNW has good propagation to Asia in the 40M region in the mornings (as you're undoubtedly aware, as it's similar in California). 400KW PEP sounds reasonable, as the signal often slams my radios very loudly.

I've heard the pips, also, although that was a few kHz down from 6838. This morning around 0844 UTC (0044 Pacific) I heard a continuous, repeating transmission of 8 pips, with the last one having a short data burst. It sounded like a marker signal of some sort. It was centered on 6833, and was about 5-7 kHz wide on my radio.

Of course, this may be a different transmitter and station entirely. 6838, where I've been hearing the digital hash, was MIA early this a.m. (0844 UTC), and the carrier I often hear on 6938 was also MIA.

[BoomboxDX]

I've been monitoring the HFT / Digital hash station on 6838 kHz fairly often, and it seems to be very active at diverse hours throughout the day.

It's loudest during the early mornings Pacific time, when sometimes it will be S5/5, slamming my DX-440 + 12 ft wire (and other radios on a longer wire). Other times it's very weak.

It seems to fade out around 8-10 a.m. Pacific, and I'll sometimes hear it during the late afternoon as well. Right now it's a weak S1-2/5, and two hours ago it was not transmitting.

I'm still trying to wrap my head around the concept of a one-way transmission somehow benefitting 'high frequency trading'. One would think that for a transmitter to benefit high frequency stock trading, there would have to be a return transmission, to complete the trading circuit.

This is why many in stock trading who say HFT on HF doesn't exist insist that for high frequency trading to work, the comms have to be 'co-located', i.e. within blocks of each other, not with a component blasting the ionosphere from 1000 or more miles away. I recently got into two lengthy online arguments with guys who insisted they knew High Frequency trading -- one who claimed to have worked in stock trading IT -- who both insisted that using Shortwave for HFT is impractical and a non-starter.

I still don't understand what station I'm hearing. If it's the one in Ritzvile, WA, why eastern WA? What does it serve? Japan? Taiwan?

Many of the transmissions aren't during Japan or Taiwan's stock market hours. But some are. Are they merely sending market-related data? Then why via HF? If it's just data, why is speed so important, if the high frequency comms are only one-way?

There are a lot of variables here, and maybe these transmitters are just blasting out empty data to explore the concept.

Anyway, so far, the 6838 is much more active than it was a couple weeks ago, it's peak reception signals here in Western WA where I live are between 1 a.m. and 9 a.m. Pacific (i.e. 0900 UTC to 1700 UTC), and I've heard it a few other times during the day (usually very weak, almost in the static, which is natural for a 7 MHz signal during daylight hours), and it seems to be off the air between afternoon and around 9-10 p.m. Pacific (i.e., 0000-0600 UTC or thereabouts).

As I write this at 0920 UTC / 1:20 a.m. Pacific, it's been churning and blasting away at S2/5 for a couple hours or so.

[BoomboxDX]

After reading through the thread again, I think I misidentified the station Token was referring to -- WP2XCZ Ritzville is apparently on 6860, and the only curious transmissions I've heard in the past few months in that part of the spectrum is the UNID digital hash (S5/5 much of the time) on 6838 and sometimes a moderate to weak carrier on 6938.

The 6860 frequency usually is silent here, just static.

I also looked up the FCC Ritzville, WA station data and it seems to have a license for transmissions between 6900 and 7000. I don't know how much latitude the FCC gives to experimental stations, but obviously because the station I'm hearing is below 6900, it's not Ritzville, it's not WP2XCZ, and I am not sure the OP's station is WP2XCZ if WP2XCZ has a license for 6900-7000 kHz (unless the FCC allows your to transmit outside the designated range).

I also looked up the address, and if you look on Google maps for the Ritzville address (2076 Bauer Rd), I don't see any evidence of towers. Just what looks like possible boreholes in the ground, but no towers, no electric lines (which would obviously be needed), no access drive either. I don't know how old the Google map satellite pic is, but Bing maps shows even less. Very odd. Definitely no shadows indicating towers being present, either.

Sorry for any confusion here. In the future if I post info on 6838 kHz, I'll start a new thread.

[Token]

After reading through the thread again, I think I misidentified the station Token was referring to -- WP2XCZ Ritzville is apparently on 6860, and the only curious transmissions I've heard in the past few months in that part of the spectrum is the UNID digital hash (S5/5 much of the time) on 6838 and sometimes a moderate to weak carrier on 6938.

The 6860 frequency usually is silent here, just static.

I also looked up the FCC Ritzville, WA station data and it seems to have a license for transmissions between 6900 and 7000. I don't know how much latitude the FCC gives to experimental stations, but obviously because the station I'm hearing is below 6900, it's not Ritzville, it's not WP2XCZ, and I am not sure the OP's station is WP2XCZ if WP2XCZ has a license for 6900-7000 kHz (unless the FCC allows your to transmit outside the designated range).

I also looked up the address, and if you look on Google maps for the Ritzville address (2076 Bauer Rd), I don't see any evidence of towers. Just what looks like possible boreholes in the ground, but no towers, no electric lines (which would obviously be needed), no access drive either. I don't know how old the Google map satellite pic is, but Bing maps shows even less. Very odd. Definitely no shadows indicating towers being present, either.

Sorry for any confusion here. In the future if I post info on 6838 kHz, I'll start a new thread.

OK, do you have a recording or image of the 6838 kHz signal?

As for the Baur Rd address, I just looked at Google Earth and I note that the imagery date is 2023.  I don't see towers there, but I do see possible tower bases.

Re WP2CXZ, 6900 - 7000 KHz and the 6860 kHz of this signal.  I have no answer for that.  But I can say that so far the only Morse IDs I have seen with this signal, a strong carrier and periodic short duration PSK data 30+ kHz wide, has been WP2CXZ.  Since the waveforms used in HFT appear to all be proprietary and unique, I assume that anyone using this waveform has some connection to WP2CXZ, or their company, RCA Telecom LLC (and RCA Telecom LLC has several HFT licenses across the country).

The same company (RCA Telecom LLC) had other licenses (I think they are now expired / superseded) that did include the 6860 kHz frequency.  I will note that the same company, RCA Telecom LLC, has a business interest in 3702 Tulalip, Everett, WA, (they filed for permission to use the property in 2020) and there appears to be a tower with a couple HF beams on it there.

T!

[BoomboxDX]

After reading through the thread again, I think I misidentified the station Token was referring to -- WP2XCZ Ritzville is apparently on 6860, and the only curious transmissions I've heard in the past few months in that part of the spectrum is the UNID digital hash (S5/5 much of the time) on 6838 and sometimes a moderate to weak carrier on 6938.

The 6860 frequency usually is silent here, just static.

I also looked up the FCC Ritzville, WA station data and it seems to have a license for transmissions between 6900 and 7000. I don't know how much latitude the FCC gives to experimental stations, but obviously because the station I'm hearing is below 6900, it's not Ritzville, it's not WP2XCZ, and I am not sure the OP's station is WP2XCZ if WP2XCZ has a license for 6900-7000 kHz (unless the FCC allows your to transmit outside the designated range).

I also looked up the address, and if you look on Google maps for the Ritzville address (2076 Bauer Rd), I don't see any evidence of towers. Just what looks like possible boreholes in the ground, but no towers, no electric lines (which would obviously be needed), no access drive either. I don't know how old the Google map satellite pic is, but Bing maps shows even less. Very odd. Definitely no shadows indicating towers being present, either.

Sorry for any confusion here. In the future if I post info on 6838 kHz, I'll start a new thread.

OK, do you have a recording or image of the 6838 kHz signal?

As for the Baur Rd address, I just looked at Google Earth and I note that the imagery date is 2023.  I don't see towers there, but I do see possible tower bases.

Re WP2CXZ, 6900 - 7000 KHz and the 6860 kHz of this signal.  I have no answer for that.  But I can say that so far the only Morse IDs I have seen with this signal, a strong carrier and periodic short duration PSK data 30+ kHz wide, has been WP2CXZ.  Since the waveforms used in HFT appear to all be proprietary and unique, I assume that anyone using this waveform has some connection to WP2CXZ, or their company, RCA Telecom LLC (and RCA Telecom LLC has several HFT licenses across the country).

The same company (RCA Telecom LLC) had other licenses (I think they are now expired / superseded) that did include the 6860 kHz frequency.  I will note that the same company, RCA Telecom LLC, has a business interest in 3702 Tulalip, Everett, WA, (they filed for permission to use the property in 2020) and there appears to be a tower with a couple HF beams on it there.

T!

Thank you Token, for your response.

RE: the satellite photos: I was unable to see the date of the actual images, except the ones at the bottom, which said 2026 -- probably a running copyright date. Although the potential 'tower bases' do appear as areas of digging on the Google maps pic, there still isn't any other infrastructure noticed at that time. But, if that was 3 years ago, I suppose power my have been run out there, and there may be more going on in 2026 that wasn't shown in the satellite pics. If there is a facility now at Ritzville, I haven't heard anything on 6860, at least not within the last year or so. Just 6838 and a carrier on 6938 that runs early mornings (which may be completely unrelated).

RE: 6838 kHz Digital hash: Sadly, I don't have recording capability, and even if I did, it would be off my phone and it would sound mediocre. But that said, three mornings ago when the 6838 Digital hash was starting to fade on my DX-440 (+ indoor wire), I found several online SDRs -- the KFS one, the North Utah one, and a couple in PA and GA.

The KFS SDR had the digital signal on 6838 going full bore, much stronger than it was here at my QTH near Seattle. It sounded S5 and the waveform was bright and wide on the waterfall. The North Utah SDR's (I picked up the 6838 on both of them -- the omni antenna one, and the east beam antenna one) picked up the signal even louder. The East beam one seemed to be stronger.

The Phoenix SDR I found had it weak, maybe a little stronger than I was getting it here. The PA and GA SDR's had nothing.

Here's the links to the KFS and N. Utah SDR's:
KFS:
http://websdr1.kfsdr.com:8901/?tune=7200lsb
North Utah:
https://www.sdrutah.org/

I know you have your own SDR and antennas, but I'm just posting these because I found it interesting that as late as 9:30 a.m. Pacific, when the signal was fading down from S5 to S1- on my radio, that the KFS and N Utah SDRs had it full blast. Some of it is their antennas and equipment. Some of it is obviously propagation may be better to the Southern latitudes -- and/or the digital signal may be beamed at California.

I tried doing searches on the FCC database for the signal on 6838, but couldn't really find anything.

As for the signals' purpose, so far I can't correlate the 6838 transmissions with any particular stock market openings or closings, or correlate it with any propagation patterns, unless it's in the Midwest and aimed at California. The digital signals on 6838 usually come in 30 second transmissions, with maybe half a second before the next one. On Thursday, the transmissions turned continuous. That was the first time I heard a continuous digital transmission on 6838. Before then, they were always 30 second bursts. And last year, if memory serves, I was hearing a carrier during the mornings, with no digital transmissions. The digital transmissions started a month or two ago.

EDIT to ADD: the Digital signal, by the way, is the noisiest racket I've heard on HF. It makes STANAG sound pleasing. As I type this edit, at 0654 Pacific/1454 UTC, it's blasting away, about S3+ to S4+ on my DX440, using my indoor, 12 ft den antenna

EDIT to ADD #2: In case I neglected to mention, in my hours (yes, sometimes hours) of monitoring this noisy, phasing racket over the last week or so I've never yet heard even one peep of a CW ID. I suspect it's possible, if this is HFT, that some of the HFT stations may still have exemptions. Maybe none of them do. The one article I saw implied that it was mandatory for all of them. It's possible this is not HFT at all, but military or some other utility.

[j333]

Sorry off topic.... did you upload those screen shot images directly to the board or are you hosting somewhere and using the "img" tags?

[tiNG]

Hi j333.

You can find out for yoursel - just rightclick "open image in new tab" or something like this and see the URL in the address-line.

YOu have to use the [img]-tags.

Hope this helps.