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Author Topic: 27255 kHz 27.255 MHz FSK Data Link ΣSDR COMMSIGMA SDR KiwiSDR 1720 UTC 14 Dec 18  (Read 138 times)

Offline R4002

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27255 kHz 27.255 MHz, 25 watts average or carrier power maximum TX under Part 95 of FCC rules.  There's a FSK data link signal readable on the ΣSDR KiwiSDR.  Not sure if this is the same network heard on the New York SDRs but it exhibits the same characteristics, with around 8 kHz of bandwidth. 

Listenable in FM or NFM mode but I generally tune into it in USB mode.  Some minor AM CB voice traffic QRM but when the frequency is clear you can see/hear the FSK signals buzzing away, albeit much weaker than other data networks on 27.255 MHz that I've heard. 
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers - VHF LMR network operator

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Have you tried decoding the FSK? Curious if there is any readable data that might reveal its purpose.

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CT/MA border
Afredri SDR-Net with multiband dipole at 65 ft.
KiwiSDR online - http://sigmasdr.ddns.net:8073/

Offline R4002

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I do not have the capability to do so.  Check out the Highland Falls, NY KiwiSDR and the Poughquag, NY KiwiSDR, both of those receivers have similar FSK data networks local to them on 27.255.  If you have the capability to decode the FSK I would be very interested to hear what data is being sent. 

The Highland Falls, NY KiwiSDR is close to an extremely active data link network on 27255, from what I can tell there’s at least 3-4 different transmitters (going by differences in signal strength) and one data burst every 1-2 seconds.
U.S. East Coast, various HF/VHF/UHF radios/scanners/receivers - VHF LMR network operator