Inactive/Rare Signals

Click the name of a signal to see more detailed information, possible decoding, and additional sound and waterfall samples

Signal Name	Description	Frequency	Mode	Modulation	Bandwidth	Location	Sample Audio	Waterfall image
1G Advanced Mobile Phone System (AMPS)	The first generation of cellular mobile telecommunications, which used analogue NFMNarrowband Frequency Modulation voice.	824 MHzMegaHertz (MHz) 10^6 Hz — 894 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation	FMFrequency Modulation, FSKFrequency-Shift Keying	10 kHzKiloHertz (kHz) 10^3 Hz — 30 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
AMSAT-P3D	AMSAT-P3D (Known as Phase 3D, OSCAR-40, and AO-40) is a amateur radio satellite built by AMSAT. As of 2004, the satellite's systems have failed.	145.805 MHzMegaHertz (MHz) 10^6 Hz — 24,048.285 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying	1.6 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
ARQ-M2-242	ARQAutomatic Repeat reQuestAutomatic Repeat Query-M2-242 (Also known as TDM 242, TDM-2, 96-TDM, and ARQAutomatic Repeat reQuestAutomatic Repeat Query-28) is a two-channel time division multiplexed telex system. This is the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 242 standard version. Used in Aeronautical, Marine, and Point-to-Point services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ-M2-342	ARQAutomatic Repeat reQuestAutomatic Repeat Query-M2-342 (Also known as TDM 342, TDM-2, 96-TDM, and ARQAutomatic Repeat reQuestAutomatic Repeat Query-28) is a two-channel time division multiplexed telex system. This is the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 342 standard version. Used in Aeronautical, Maritime, and Point-to-Point services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ-M4-242	ARQAutomatic Repeat reQuestAutomatic Repeat Query-M4-242 (Also known as TDM 242, TDM-4, 192-TDM, and ARQAutomatic Repeat reQuestAutomatic Repeat Query-56) is a four-channel time division multiplexed telex system. This is the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 242 standard version. Used in Aeronautical, Maritime, and Point-to-Point services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	250 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ-M4-342	ARQAutomatic Repeat reQuestAutomatic Repeat Query-M4-342 (Also known as TDM 342, TDM-4, 192-TDM, and ARQAutomatic Repeat reQuestAutomatic Repeat Query-56) is a four-channel time division multiplexed telex system. This is the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 342 standard version. Used in Aeronautical, Maritime, and Point-to-Point services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ-N	ARQAutomatic Repeat reQuestAutomatic Repeat Query-N is a synchronous dual channel ARQAutomatic Repeat reQuestAutomatic Repeat Query mode identical to ARQAutomatic Repeat reQuestAutomatic Repeat Query-E, with the only difference being that ARQAutomatic Repeat reQuestAutomatic Repeat Query-N has no symbol inversions. Formerly used by Italian Diplomatic services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	85 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 850 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ6-90	ARQ6-90, also known as ARQAutomatic Repeat reQuestAutomatic Repeat Query-6-90 and ARQAutomatic Repeat reQuestAutomatic Repeat Query-6/90, is a 6-character block simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system formerly used by French and Italian diplomatic services exchange of teletype-data. It is no longer used or seen today.	10 MHzMegaHertz (MHz) 10^6 Hz — 23 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	700 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
ARQ6-98	ARQ6-98, also known as ARQAutomatic Repeat reQuestAutomatic Repeat Query-6-98 and ARQAutomatic Repeat reQuestAutomatic Repeat Query-6/98, is a 6-character block simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system formerly used by French and Italian diplomatic services for the exchange of teletype-data. It is no longer used or seen today.	10 MHzMegaHertz (MHz) 10^6 Hz — 23 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
AUTOSPEC	AUTOSPEC is a synchronous FECForward Error Correction teletype system used by British coastal stations to communicate with North Sea oil rigs. Also known as Autospec-bauer, Bauer, and Autospec Mk1. This signal is most likely phased out.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	350 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Accurate positioning by Low Frequencies (ALF)	Accurate positioning by Low Frequencies, a former German DGPS navigation system. No longer in use as of 2013.	123.7 kHzKiloHertz (kHz) 10^3 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying	2.1 kHzKiloHertz (kHz) 10^3 Hz	Germany
BR-6028	BR-6028 is a VFTVoice Frequency Telegraphy (Voice Frequency Telegraph) frequency and time diversity modem using 7 data channels. It is sometimes also known as BARRIE, USA-7, or 6028.	5.75 MHzMegaHertz (MHz) 10^6 Hz — 15.937 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	3.1 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
CIS 3x100 VFT	Three CISCommonwealth of Independent States (CIS), the former Soviet Republic-14 signals overlaid on top of each other in a 3100 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). VFTVoice Frequency Telegraphy bandwidth, operating at 100 bdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	3.1 kHzKiloHertz (kHz) 10^3 Hz	Russia
CIS 3x144 VFT	Three 144 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. FSKFrequency-Shift Keying signals in a 3100 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). VFTVoice Frequency Telegraphy bandwidth. Reportedly phased out.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	3.1 kHzKiloHertz (kHz) 10^3 Hz	Russia
CIS 3xBaudot-50 VFT	Three 50 bdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. Baudot signals in a 3100 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). VFTVoice Frequency Telegraphy bandwidth.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	3.1 kHzKiloHertz (kHz) 10^3 Hz	Russia
CIS-11	CISCommonwealth of Independent States (CIS), the former Soviet Republic-11 (Also known as TORG-11) is a radio duplex teleprinter system used by Russian meteorological stations	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	650 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Russia
CIS-1280	CISCommonwealth of Independent States (CIS), the former Soviet Republic-1280 is a OQPSK (Offset Quadrature Phase Shift-Keying) modulation data modem signal. Also known as Soviet Mil(MOD)/FAPSIFederal Agency of Government Communications and Information (Russian Agency)/PTTPush To TalkPress to TransmitMinistries of Postal, Telephone, and Telegraph Service (Soviet Agency) system. These stations are recognizable in that they are all placed on .081 offsets from a kilohertz or half kilohertz point.	3 MHzMegaHertz (MHz) 10^6 Hz — 13.369 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying	1.28 kHzKiloHertz (kHz) 10^3 Hz	Russia
CIS-14	Also known as AMOR and AMOR96. Synchronous FSKFrequency-Shift Keying duplex teleprinter system with ARQAutomatic Repeat reQuestAutomatic Repeat Query.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	650 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Russia
CIS-16	CISCommonwealth of Independent States (CIS), the former Soviet Republic-16 is a BPSKBinary Phase-Shift Keying (1 bit per symbol) 16-tone mode, possibly transmitted from a modified AT-3004D or AT-3104 type Russian military transceiver. Also known as CISCommonwealth of Independent States (CIS), the former Soviet Republic 16x75 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. for the 75 bdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. speed in each of the 16 sub channels.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying	2.7 kHzKiloHertz (kHz) 10^3 Hz	Russia
CIS-300	Known as CISCommonwealth of Independent States (CIS), the former Soviet Republic-300 Burst, FSKFrequency-Shift Keying mode used with 300 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. rate with a starting and ending tone on the upper part of the signal.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	370 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Russia
CIS-8181	CISCommonwealth of Independent States (CIS), the former Soviet Republic-8181 is an FSKFrequency-Shift Keying modem used by the Russian navy.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Russia
CLOVER-I	CLOVER-I was the first iteration of the Clover series of digital modes. Was never released for commercial use, replaced by CLOVER-II. Also known as Cloverleaf.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying, QAMQuadrature Amplitude Modulation	100 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
CRY2001 Voice Scrambler	CRY2001 is a voice scrambling mode used on Sailor CRY2001 Scramblers. Fisherman often use these modes to communicate with privacy.	3 MHzMegaHertz (MHz) 10^6 Hz — 300 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	3 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
CV-786	CV-786 is a wideband FSKFrequency-Shift Keying mode built in Rockwell-Collins MDM-2001 modems. Also known as TRC-75, as it was used in TRC-75 transceivers. A military-based Radio TeleTYpe mode.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	900 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Coherent BPSK	Coherent BPSKBinary Phase-Shift Keying (1 bit per symbol), also known as C-BPSKBinary Phase-Shift Keying (1 bit per symbol), was an experimental amateur mode developed by Bill DeCarle VE2IQ.	138 kHzKiloHertz (kHz) 10^3 Hz — 18.081 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying	200 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Coherent CW	Coherent CWContinuous Wave (also known as CCW) was a strictly timed morse code mode designed by Ray Petit W7GHM (The same inventor of CLOVER). CCW depended on accurate timing from both receiver and transmitter.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	OOKOn-Off Keying Modulation	1 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Coquelet	Coquelet is an MFSKMultiple Frequency Shift-Keying system, similar to Piccolo. Also known as COQ-8, COQ-12, and COQUELET 8 V 2. Uses ITA-2 charset. It's two main modes are Coquelet-8 and Coquelet-13. No longer in use.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	MFSKMultiple Frequency Shift-Keying	300 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 500 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
DUP-ARQ	DUP-ARQAutomatic Repeat reQuestAutomatic Repeat Query, also known as ARTRAC and 125-ARTRAC, is a semi-duplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system once used by Thai and Hungarian Diplomatic services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	325 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
DUP-ARQ-2	DUP-ARQAutomatic Repeat reQuestAutomatic Repeat Query-2 (also known as ARTRAC II) is a further development of the DUP-ARQAutomatic Repeat reQuestAutomatic Repeat Query system and the system characteristics are very similar. DUP-ARQAutomatic Repeat reQuestAutomatic Repeat Query-2 allows transmission of ITA-2 (Baudot) or ITA-5 (ASCII) characters depending on the application.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	1.3 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
DUP-FEC-2	DUP-FECForward Error Correction-2 is a further development of the DUP-ARQAutomatic Repeat reQuestAutomatic Repeat Query system and the system characteristics are very similar. Uses FECForward Error Correction instead of ARQAutomatic Repeat reQuestAutomatic Repeat Query and runs at either 125 bdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. or 250 bdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second..	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	1.1 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Delfi-C3 Telemetry	Delfi-C3 Telemetry was a telemetry signal sent from the Delfi-C3 university-class satellite.	145.87 MHzMegaHertz (MHz) 10^6 Hz	LSBLower Side Band Modulation	BPSKBinary Phase-Shift Keying (1 bit per symbol)	10 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
DeltaFix	DeltaFix was a DGPS system that was used to provide precision positioning used in the survey and oceanographic industry.	1.7 MHzMegaHertz (MHz) 10^6 Hz — 3.4 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	250 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
DominoF	DominoF was the first experimental implementation of the Domino family of IFKIncremental Frequency Keying modes, developed by Con ZL2AFP. DominoF used dual interleaved tone sets. Superseded by DominoEX.	1.838 MHzMegaHertz (MHz) 10^6 Hz — 28.08 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	IFKIncremental Frequency Keying	220 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
Duga 3	Duga (Russian: Дуга́) was a Soviet over-the-horizon radar system used as part of the Soviet missile defense early-warning radar network. The system operated from July 1976 to December 1989. Two operational Duga radars were deployed, one near Chernobyl and Chernihiv in the Ukrainian SSR (present-day Ukraine), the other in eastern Siberia. The Duga systems were extremely powerful, over 10 MW in some cases, and broadcast in the shortwave radio bands. They appeared without warning, sounding like a sharp, repetitive tapping noise at 10 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., which led to it being nicknamed by shortwave listeners the Russian Woodpecker.	7 MHzMegaHertz (MHz) 10^6 Hz — 19 MHzMegaHertz (MHz) 10^6 Hz			20 kHzKiloHertz (kHz) 10^3 Hz — 800 kHzKiloHertz (kHz) 10^3 Hz	Ukraine
FEC-A	FECForward Error Correction-A, also known as FECForward Error Correction-100 or FECForward Error Correction-100A, is a synchronous simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system that uses the ITA 2 alphabet. This mode was once used by many embassies, diplomatic services, and news agencies worldwide. This mode was developed by Siemens.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	100 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 1.2 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
FLASH-OFDM	Fast Low-latency Access with Seamless Handoff Orthogonal Frequency Division Multiplexing (FLASH-OFDMOrthogonal Frequency-Division Multiplexing) is a mobile data access technology developed by Flarion.	450 MHzMegaHertz (MHz) 10^6 Hz	WFMWideband Frequency Modulation	MC-CDMACode Division Multiple Access	2 MHzMegaHertz (MHz) 10^6 Hz	Finland, Slovakia, Germany, United States
Gandalf MDT	Gandalf MDTMobile Data Terminal, A mobile data terminal (MDT) is a computerized device used in public transit vehicles, taxicabs, commercial trucking fleets, military logistics, and emergency vehicles, such as police cars, to communicate with a central dispatch office. was developed by Gandalf Mobile Systems, a subsidiary of Canadian company Gandalf Technologies. Used primarily by taxi and courier services in Canada and the United States. This protocol was used in Gandalf's Cabmate systems.	150 MHzMegaHertz (MHz) 10^6 Hz — 450 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation	4FSK4-Level Frequency Shift Keying	10 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Globe Wireless HF Network	Globe Wireless' Maritime Digital Radio was a system of 24 stations around the globe offering data services to large cargo vessels. Since 2014, GW has discontinued their HFHigh Frequency (3-30 MHz) network.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying, FSKFrequency-Shift Keying, OFDMOrthogonal Frequency-Division Multiplexing	400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 2 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Golay Paging (GSC)	Golay Paging (or Golay Sequential Code, GSC) is a one-way 2-FSKFrequency-Shift Keying paging format developed by Motorola. It is capable of transmitting tone, numeric, alphanumeric, and voice pages.	33 MHzMegaHertz (MHz) 10^6 Hz — 932 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation	FSKFrequency-Shift Keying	2.6 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
HC-ARQ	Haegelin Crypto ARQAutomatic Repeat reQuestAutomatic Repeat Query (HC-ARQAutomatic Repeat reQuestAutomatic Repeat Query) was an FSKFrequency-Shift Keying synchronous simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system used by the UN and International Rescue Committee. This mode has been phased out and is no longer in use.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	300 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
HNG-FEC	HNG-FECForward Error Correction was a full duplex system developed and used solely by the Ministry of Foreign Affairs in Hungary. Used 100.05 bdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. with 500 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). shift FSKFrequency-Shift Keying. This mode is no longer used today.	2.4 MHzMegaHertz (MHz) 10^6 Hz — 24 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Hungary
High Power Auroral Stimulation (HIPAS)	The HIPAS (HIgh Power Auroral Stimulation) Observatory was a research facility, built to study the ionosphere and its influence on radio communications. It was located 25 miles east of Fairbanks, Alaska in the Fairbanks North Star Borough area.	2.85 MHzMegaHertz (MHz) 10^6 Hz — 4.53 MHzMegaHertz (MHz) 10^6 Hz				United States	—
HyperFix	HyperFix was a radio-navigation system developed by Racal. Was used by vessels and ships. Has largely been phased out in favor of Differential GPS.	1.6 MHzMegaHertz (MHz) 10^6 Hz — 3.4 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)		250 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
IRA-ARQ	IRA-ARQAutomatic Repeat reQuestAutomatic Repeat Query, also known as BULG-ASCII and ASCII-ARQAutomatic Repeat reQuestAutomatic Repeat Query, is a high data rate ARQAutomatic Repeat reQuestAutomatic Repeat Query FSKFrequency-Shift Keying system used by Bulgarian, Slovakian, and Czech diplomatic stations. The maximum speed of this mode has been seen to reach 1200 bdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second.. Not seen much much nowadays	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	650 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 1.35 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
IS-54 D-AMPS	D-AMPS, also known as IS-54 and IS-136, is a second generation (2G) mobile phone system standard which develops on analog AMPS, a 1G standard. This system is also colloquially known as TDMATime Division Multiple Access.	824 MHzMegaHertz (MHz) 10^6 Hz — 894 MHzMegaHertz (MHz) 10^6 Hz		PSKPhase-Shift Keying	30 kHzKiloHertz (kHz) 10^3 Hz		—
Inmarsat IsatM2M	IsatM2M Service operated by Inmarsat on existing Inmarsat-D/D+ infrastructure.	1,525 MHzMegaHertz (MHz) 10^6 Hz — 1,559 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	MFSKMultiple Frequency Shift-Keying	1.024 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Inmarsat-D(D+) Downlink	Inmarsat D+ (and it's predecessor, Inmarsat D) was Inmarsat's satellite paging system. The main use of the technology was in tracking trucks and buoys and SCADA applications.	1,525 MHzMegaHertz (MHz) 10^6 Hz — 1,559 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	MFSKMultiple Frequency Shift-Keying	640 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
MD-522	MD-522 (Also known as MIL-M-55529A) is a synchronous FSKFrequency-Shift Keying mode built into GRC-MD522 teletypewriter sets and used for wirelessly transmitting ASCII information. MD-522 has a narrowband, wideband, and diversity mode.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	200 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 300 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	United States
MD-674	MD-674, also known as Wireline FSKFrequency-Shift Keying, is a very old United States Military FSKFrequency-Shift Keying Modem from the 1960's. Uses 85 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). FSKFrequency-Shift Keying shift. Speeds of 50 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second., 75 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second., 100 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second., and 150 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. have been logged. No longer seen today.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	200 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 300 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	United States
MIL-STD-110-342	MIL-STD-110-342 was a US Dept. of Defense standard for a 16 channel VFTVoice Frequency Telegraphy teletype transmission. This mode was officially cancelled as of December 5th, 1995.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	3.1 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
MMP-4800	MMP-4800 was a MDTMobile Data Terminal, A mobile data terminal (MDT) is a computerized device used in public transit vehicles, taxicabs, commercial trucking fleets, military logistics, and emergency vehicles, such as police cars, to communicate with a central dispatch office. (Mobile Data Terminal) protocol developed by Canadian company Mobile Data International (MDI) in 1982 for their Mobile Data Terminals. Used by public safety and commercial industries. Phased out.	150 MHzMegaHertz (MHz) 10^6 Hz — 900 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation		12.5 kHzKiloHertz (kHz) 10^3 Hz — 25 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
Meteosat WEFAX	Meteosat WEFAX is a WEFAX used to transmit satellite images via Meteosat Satellites. WEFAX was introduced with the first Meteosat in 1977.	1,691 MHzMegaHertz (MHz) 10^6 Hz	FMFrequency Modulation	AMAmplitude Modulation, FMFrequency Modulation		Worldwide
Motorola SECURENET	Motorola SECURENET ("analog" encryption) was a secure voice option for conventional and Motorola Type II trunked systems, encoding the voice using 12kbps CVSD and encrypting the bitstream. It is easily identified by the 6 kHzKiloHertz (kHz) 10^3 Hz tone at the end of transmission. As it is not 12.5 kHzKiloHertz (kHz) 10^3 Hz FCC narrowbanding mandate compliant, it does not see much use anymore.	137 MHzMegaHertz (MHz) 10^6 Hz — 941 MHzMegaHertz (MHz) 10^6 Hz	FMFrequency Modulation	FSKFrequency-Shift Keying	16 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
NOAA ITOS High Resolution Picture Transmission (HRPT)	An analog signal broadcast from NOAA ITOS polar satellites that transmitted images from the VHRR radiometer.	1,697.5 MHzMegaHertz (MHz) 10^6 Hz	WFMWideband Frequency Modulation	FMFrequency Modulation	1 MHzMegaHertz (MHz) 10^6 Hz	Worldwide	—
Nordic Mobile Telephone (NMT)	Nordic Mobile Telephone (NMT, NMT-450, and NMT-900) is a first generation analog cell phone system. Originally designed for and by Nordic countries (Finland, Sweden, Norway, Denmark) it was widely deployed around the world. Nowadays (as of 2015) NMT is defunct.	453 MHzMegaHertz (MHz) 10^6 Hz — 960 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation	FSKFrequency-Shift Keying	25 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
POL-ARQ	POL-ARQAutomatic Repeat reQuestAutomatic Repeat Query was a duplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system used by Polish and Italian diplomatic services. This system uses the CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 476-4 alphabet with polatiry retained. No longer in use.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	350 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Europe
Piccolo	Piccolo was a MFSKMultiple Frequency Shift-Keying system developed by the UK Foreign and Commonwealth Office (FCO) to communicate with foreign embassies and UK military stations around the world. No longer used.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	MFSKMultiple Frequency Shift-Keying	180 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 300 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
RAC-ARQ	RAC-ARQAutomatic Repeat reQuestAutomatic Repeat Query, also known as MEROD and RACAL-ARQAutomatic Repeat reQuestAutomatic Repeat Query, is a teleprinter system by Racal, used in MEROD devices. MEROD stands for Message Entry and Read Out Device. Hasn't been seen since 2010.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	1 kHzKiloHertz (kHz) 10^3 Hz — 1.3 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
RUM-FEC	RUM-FECForward Error Correction, also known as ROU-FECForward Error Correction and SAU-FECForward Error Correction, is a FSKFrequency-Shift Keying FECForward Error Correction system used by Romanian diplomatic services. This is no longer used today, replaced by MIL-STD 188-110 Serial.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	750 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Romania
RUM-MOI FEC	RUM-MOI FECForward Error Correction, also known as RUM-MIL 115.76 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second., is a FSKFrequency-Shift Keying FECForward Error Correction mode used by the Romanian Ministry of Internal Affairs, supposedly under military use. This is no longer used today, replaced by MIL-STD 188-110 Serial.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Romania
Radio Telephone Network C (C-Netz)	The Radio Telephone Network C (German: Funktelefonnetz-C, abbreviated as C-Netz), was a first generation analog cellular phone system deployed and operated in Germany (at first West Germany) by DeTeMobil (formerly of Deutsche Bundespost Telekom, currently Deutsche Telekom).	450 MHzMegaHertz (MHz) 10^6 Hz	FMFrequency Modulation	FSKFrequency-Shift Keying	12.5 kHzKiloHertz (kHz) 10^3 Hz	Germany
Redundant Digital File Transfer (RDFT)	RDFT is an amateur radio digital mode used to transmit files.	9.065 MHzMegaHertz (MHz) 10^6 Hz — 9.24 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying	1.8 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
SI-ARQ	SI-ARQAutomatic Repeat reQuestAutomatic Repeat Query, also known as ARQAutomatic Repeat reQuestAutomatic Repeat Query-S and ARQAutomatic Repeat reQuestAutomatic Repeat Query-1000S, is a simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system designed by Siemens formerly used by Austrian and Indonesian diplomatic services. No longer used today.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	350 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Europe
SI-FEC	SI-FECForward Error Correction, also known as FECForward Error Correction-S, FECForward Error Correction 1000 Simplex, and FECForward Error Correction-1000S, was the FECForward Error Correction variant of SI-ARQAutomatic Repeat reQuestAutomatic Repeat Query, and was only used under extremely poor propagation conditions. SI-FECForward Error Correction was developed by Siemens and was used by Austrian and Indonesian diplomatic services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	280 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Europe
SP-14 (XP)	SP-14 (XP) was a 14 tone MFSKMultiple Frequency Shift-Keying mode with origins from the Russian Intelligence and Foreign Ministry. Also known as NUM-13. Inactive since 2005, superseded by XPA.	9 MHzMegaHertz (MHz) 10^6 Hz — 12 MHzMegaHertz (MHz) 10^6 Hz	AMAmplitude Modulation	MFSKMultiple Frequency Shift-Keying	1.2 kHzKiloHertz (kHz) 10^3 Hz	Russia
SPREAD	SPREAD, also known as AUTOSPEC Mk2, SPREAD-11, SPREAD-21, and SPREAD-51, was a FECForward Error Correction system used by Romanian diplomatic stations and the Brazilian Navy and shore stations. SPREAD is considered the successor to AUTOSPEC.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
SWED-ARQ	SWED-ARQAutomatic Repeat reQuestAutomatic Repeat Query, also known as ARQAutomatic Repeat reQuestAutomatic Repeat Query-SWE, was a Swedish simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query system used by Swedish diplomatic services. This protocol supported three packet lengths and was able to change packet length mid-transmission. No longer used today.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	600 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Sweden
Sonne	Sonne (Called Consol by the Britons) was a low-frequency radio range based radio navigation system used for long range navigation.	250 kHzKiloHertz (kHz) 10^3 Hz — 350 kHzKiloHertz (kHz) 10^3 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	OOKOn-Off Keying Modulation	1 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
TT2300	TT2300, also known as TT2300B, TT2300-ARQAutomatic Repeat reQuestAutomatic Repeat Query, TRA-2300, and TPLEX, is an 8MFSK synchronous system developed by Thrane & Thrane of Denmark (acquired by UK defense firm Cobham in 2012).	5.029 MHzMegaHertz (MHz) 10^6 Hz — 7.72 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	MFSKMultiple Frequency Shift-Keying	1.6 kHzKiloHertz (kHz) 10^3 Hz — 1.7 kHzKiloHertz (kHz) 10^3 Hz	Worldwide
TWINPLEX	TWINPLEX, also known as F7B4 and TWINPLEX-SITOR, was a diplex 4-FSKFrequency-Shift Keying ARQAutomatic Repeat reQuestAutomatic Repeat Query mode developed by Mackay Radio and Telegraph Company, based in New York City, in the early 1950's. TWINPLEX was used by Interpol, the United Nations, and other diplomatic services.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	MFSKMultiple Frequency Shift-Keying	450 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). — 950 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Worldwide
The 'Air Horn'	"The Air Horn" is a Russian military commandment network serving the Western Military District, which also serves the same purpose as the buzzer. It transmits on 3510 kHzKiloHertz (kHz) 10^3 Hz around the clock. So far, apart from test counts and other technical tests, it has not been heard with any actual traffic.	3.5 MHzMegaHertz (MHz) 10^6 Hz	SSBSingle-sideband modulation		5 kHzKiloHertz (kHz) 10^3 Hz	Russia
The Goose	Channel marker of the Russian military station nicknamed "The Goose", for its distinct channel marker sound. Uses 3243 kHzKiloHertz (kHz) 10^3 Hz in nighttime, and 4310kHz in daytime.	3.243 MHzMegaHertz (MHz) 10^6 Hz — 4.31 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	AMAmplitude Modulation	3.1 kHzKiloHertz (kHz) 10^3 Hz	Russia
Total Access Communication System (TACS)	A first generation analogue mobile cellular system which operated in the United Kingdom and a handful of other countries in Europe. It is also the EU's form of AMPS.	872 MHzMegaHertz (MHz) 10^6 Hz — 960 MHzMegaHertz (MHz) 10^6 Hz	NFMNarrowband Frequency Modulation	FMFrequency Modulation, FSKFrequency-Shift Keying	25 kHzKiloHertz (kHz) 10^3 Hz	Europe
VISEL	VISEL, also known as YUG-MIL 120.9 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second., FECForward Error Correction-12, and YUG-MIL FECForward Error Correction, is a synchronous teleprinter system used by the former Yugoslav military. No longer active today.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	Europe
Yachta T-219 Voice Scrambler	Yachta or Yakhta (Russian for 'Boat') T-219 is an analogue voice scrambler. It is unique in that an FSKFrequency-Shift Keying sync signal is transmitted in the middle of the main signal, with the scrambled voice stream split above and below the FSKFrequency-Shift Keying signal.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	FSKFrequency-Shift Keying	2.7 kHzKiloHertz (kHz) 10^3 Hz	Russia
Yugoslavian 16-Tone Modem	The Yugoslavian 16-Tone Modem, also known as YUG-Diplo 16-Tone, is a 16 tone OFDMOrthogonal Frequency-Division Multiplexing PSKPhase-Shift Keying modem used in former Yugoslavia for diplomatic use. No longer used today.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying, OFDMOrthogonal Frequency-Division Multiplexing	2.1 kHzKiloHertz (kHz) 10^3 Hz	Europe
Yugoslavian 20-Tone Modem	The Yugoslavian 20-Tone Modem, also known as YUG-MIL 20-Tone and YUG Diplo 20-Tone, is a 20 tone OFDMOrthogonal Frequency-Division Multiplexing PSKPhase-Shift Keying modem used in former Yugoslavia for military and diplomatic use. No longer used today.	3 MHzMegaHertz (MHz) 10^6 Hz — 30 MHzMegaHertz (MHz) 10^6 Hz	USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)	PSKPhase-Shift Keying, OFDMOrthogonal Frequency-Division Multiplexing	2.2 kHzKiloHertz (kHz) 10^3 Hz	Europe