27.940 MHz Data Stream + Paging 27940 kHz 27.94MHz Data [G8JNJ SDR] 4 June 2024

[R4002]

Tune in time: 1415 UTC.  Seems like the signal is fading out by the time I tuned in. 

Bandwidth approx 6 kHz, seems like a MFSK data signal with a "carrier" signal on 27940 kHz... with "pulsing" sound in AM, FM and SSB.  POCSAG paging signals on top of the data signal.  Unlike the data signal, the POCSAG pager signals are not nonstop. 

Some very strong FM CB radio signals noted at 1418 UTC.  UK FM CB comms, UK FM CB Channel 35, frequency 27941 FM 27.94125 MHz FM 27.941.25 MHz FM.  Severe QRM from the pager signals and data link on 27.940 MHz. 

Aside from being used for land mobile business type comms LMR PMR PLMR taxi cab radio dispatch taxi controllers out of Russia and elsewhere, 27.94 MHz is also one of the 27MHz Australian marine band frequencies.   The Australian 27 MHz marine band is AM mode A3 emission A3E AM radiotelephone maritime mobile service ship to ship ship to shore 

27.680 MHz   Commercial, Calling ship-ship, shore-shore - 27MHz marine channel 68 CH68
27.720 MHz   Pro. fishing, Calling ship-ship , shore-shore CH72
27.820 MHz   Pro. fishing, Calling ship-ship , shore-shore 27 MHz AU marine radio channel 82 CH82
27.860 MHz   Distress, Safety & Calling (supp. to 27.880) CH86
27.880 MHz   Distress, Safety & Calling Emergency Channel 27.88MHz - 27MHz marine channel 88 CH88
27.900 MHz   Non-commercial, Calling & ship-shore 27.9 MHz channel 90 CH90
27.910 MHz   Non-commercial, Calling & ship-shore 27.91 MHz CH91 Channel 91
27.940 MHz   Non-commercial, Calling & ship-shore/ship 27.94MHz 27,940 kHz 27940 kHz channel 94 CH94
27.960 MHz   Non-commercial, Calling & ship-ship 27.96MHz 27 MHz marine channel 96 CH96
27.980 MHz   Rescue etc., Calling & ship-ship, shore-shore 27.98 MHz - 27MHz marine radio channel 98 CH98

Those are the official channels, with private marinas, SAR, sea rescue, etc. organizations often using additional private channels in the 27.500 MHz to 28 MHz range (eg. 27.70 MHz, 27.75 MHz, 27.76 MHz, 27.80 MHz, 27.84 MHz, 27.85 MHz, etc.)