27.195 MHz Data Link 3.9 kHz Bandwidth MFSK - October 6th, 2026

[R4002]

I've noticed this several times before when propagation is favoring points south of the border.  Notably, Portuguese speaking chatter has been noted today, 10/06/2026 October 6th, 2026.  06.10.2026.  27.195MHz 6 Oct 2026 06 October 2026

Anyway, this signal seems to be centered on 27195 kHz, with a small amount (for 11 meters) of drift.  Roughly centered on 27194.75 kHz or 27194.8 kHz instead of dead on 27195.0 kHz.  Bandwidth is just under 4 kHz.  RCRS regulations allow for up to 8 kHz and this signal meets those requirements.  27.195MHz 27195kHz 27,195.0 MFSK FSK data signal 4 watt 4w 4 watts Class C Channel 19A +10kHz Switch +10k switch

It is a nearly-constant series of MFSK data bursts.  Tunable best in USB or LSB mode (SSB mode), but can be heard in AM and FM.  The bottom edge is at around 27192.7 kHz and the upper edge is at about 27196.9 kHz...so emission designator would be 3K90F2D or 3K9F3D if I am remembering correctly.  4K00F2D would work as would 3K80F3D (I think).  I could be wrong about the emission, but it is somewhat unique.  I also don't believe I have encountered it on any of the other 6 RCRS/data frequencies.    It is not the same as most of the paging signals found on 26-28 MHz (and also VHF low band), which at least sound like POCSAG. 

I have come across similar signals on other frequencies listening to UK and European based SDR receivers on the following frequencies:

26.540 MHz 26540 kHz - similar data signals
26.590 MHz 26590 kHz - similar data signals, paging signals found on 26.5875 MHz and 26.600 MHz
26.600 MHz 26600 kHz - data and paging signals
26.605 MHz 26605 kHz - data and paging signals
26.640 MHz 26640 kHz - similar data signals, paging signals found on 26.635 MHz and 26.645 MHz
26.690 MHz 26690 kHz - similar data signals, paging signals found on 26.695 MHz
26.740 MHz 26740 kHz - similar data signals, paging signals found on 26.745 MHz
26.865 MHz 26865 kHz - various other data and voice signals noted on this frequency
26.875 MHz 26875 kHz - various other data and voice signals noted on this frequency
26.885 MHz 26885 kHz - various other data and voice signals noted on this frequency
26.895 MHz 26895 kHz - various other data and voice signals noted on this frequency
26.900 MHz 26900 kHz - along with other signals, including CCIR and POCSAG paging signals
26.905 MHz 26905 kHz - various other data and voice signals noted on this frequency
26.915 MHz 26915 kHz - various other data and voice signals noted on this frequency
26.925 MHz 26925 kHz - various other data and voice signals noted on this frequency
26.945 MHz 26945 kHz - coming out of Russia and the CIS (former USSR), 2 watt paging/data link frequency
26.960 MHz 26960 kHz - coming out of Russia and the CIS (former USSR), 2 watt paging/data link frequency
27.080 MHz 27080 kHz - data and paging signals - heard when band was open to Eastern Europe/Russia
27.140 MHz 27140 kHz - data and paging signals - heard when band was open to Eastern Europe/Russia
27.540 MHz 27540 kHz - only similar data signals noted on this frequency
27.590 MHz 27590 kHz - only similar data signals noted on this frequency
27.640 MHz 27640 kHz - only similar data signals noted on this frequency
27.750 MHz 27750 kHz - data and paging signals

There are no doubt others. 

Sporadic voice traffic was also noted on 27.195 MHz (all in AM mode).  Sounded like U.S. truckers or similar user, using the +10 kHz switch function to get to the "hidden" channel between CB channel 19 and CB channel 20.