HF Modes Currently Active

These modes have been reported in various places over the couple of years. Keep in mind that although a particular mode can be decoded, there are several that are encrypted, and therefore unreadable. One can use analysis tools such as ACF analysis to determine this, but we may never know what such signals are actually saying.

We have pages set up with just waterfalls (useful for quick searches) here;

• HF Active Mode Waterfalls Page 1
• HF Active Mode Waterfalls Page 2

The PACTOR references are shown in bold will redirect to the HF Digital Amateur Radio article on this wiki to link to articles that describe the protocols in more detail. PACTOR1 through 3 have been known to be used in the amateur radio service, as well as in the maritime service, as noted. ALE has also been known to be used in the amateur service.

'Last Seen' references are the last time this mode was seen in the UDXF logs.

Active Modes

Mode or Description	Synonym	Notes	Waterfall Page
ARINC 635	HFDL		HFDL Waterfall
	HF ACARS
	HF DATALINK
BAUDOT	ITA-2	misnomer; ITA2 is coding scheme.	Baudot Waterfalls
	RTTY
CCIR493-4 Selcall	CODAN 8580	Misnomer; Radio Modem Name	CCIR493 Waterfall
Chinese 4 plus 4 Modem		encrypted
CODAN CHIRP		occasional use	CODAN Chirp Waterfall
CW	Morse	heavily used by Russ Mil (AF, etc.)	CW Waterfall
FAX			FAX Waterfall
FSK100	POL-FSK	Uses 63bd/125bd BPSK too; encrypted	FSK100 Waterfalls
	AK10	per Hoka
GMDSS/DSC	Maritime Selcall		GMDSS DSC Waterfall
MIL-STD-188-110A		encrypted	Waterfall de DX Asia
MIL-STD-188-110B
MIL-STD-188-141A (ALE)	2G ALE	wide use by NGO,Military some ham	ALE 2G Waterfall
MIL-STD-188-203-1A	ALLIGATOR	encrypted	Link11 Waterfalls
	Link-11
	TADIL-A
M823/SC104 DGPS	DGPS		DGPS Waterfalls
NAVTEX		A broadcast mode built on SITOR-B	NAVTEX Waterfall
PACTOR-I		used in the maritime svc
PACTOR-II		used in the maritime svc
PACTOR-III		used in the maritime svc - often encrypted
PACTOR-IV		used in the maritime svc - often encrypted
PSK		Used by Enigma P03 Polish-QPSK recently
RDFT		Mode used by HM-01;encrypted	HM01 RDFT Waterfall
SITOR-A	AMTOR MODE A	some maritime, Egyptian use	SITOR-A Waterfalls
	ARQ
	SITOR-ARQ
	TOR
SITOR-B	AMTOR MODE B		SITOR-B Waterfall
	FEC
	SITOR-FEC
STANAG4197	ANDVT	encrypted	ANDVT Waterfall
STANAG4285 2400bd Modem		encrypted	STANAG 4285 Waterfall
STANAG4481 FSK	CRATT	encrypted	STANAG 4481 Waterfalls
	LINK-4
	NATO-75
	RATT

Sporadically Active Modes

These modes have been reported occasionally over several months. Some may have been just tests; whether they'll show up in the future is anyone's guess.

Mode or Description	Synonym	Notes	Waterfall Page
Australian Forces 50bd/600bd		encrypted
Chinese MFSK PSK-8		last seen Apr 2018
Chinese MFSK		last seen May 2018
Chinese 39 tone OFDM		last seen Feb 2018
Chinese Selcall		last seen Aug 2018
Japanese Mil 8-FSK		encrypted	Jap 8Tone Waterfall
Japanese Slot Machine		Mode is QPSK1500; encrypted	QPSK1500 Waterfall
KEGURI	DPRK 600		DPRK 600 Waterfall
	DPRK 1200		DPRK 1200 Waterfall
MIL-STD-188-110
MIL-STD-188-110C
MIL-STD-188-141B App. C ALE	3G ALE	last seen Apr 2018
PACTOR-II FEC		via I5-56578 Antonio Digital blog
Polish FSK 400/800		Polish Intel via I5-56578 Antonio Digital blog-last seen Aug 2018
STANAG 4539	MIL-STD-188-110B/C App C	Seen in Oct 2018 UDXF logs	MIL 188110C Waterfall
	110C WB
STANAG 5066		encrypted; use for file xfers/emails

Amateur Related Modes Used by Other Entities

These modes have been reported once in a while by SHARES, MARS or the ICRC. Their use is sporadic at best.

Mode or Description	Synonym	Notes	Waterfall Page
AX.25 300bd FSK Packet Radio	AX.25	Protocol Name based off X.25 Standards
	PACKET
MFSK16
MT-63
OLIVIA
PSK31
WinMOR

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