HF Modes Currently Active

From The RadioReference Wiki

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;

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
BAUDOT ITA-2 misnomer; ITA2 is coding scheme. Baudot Waterfalls
CCIR493-4 Selcall CODAN 8580 Misnomer; Radio Modem Name; Chinese usage CCIR493 Waterfall
CW Morse heavily used by Russ Mil (AF, etc.) CW Waterfall
FAX FAX Waterfall
FSK100 POL-FSK Uses 63bd/125bd; BPSK/QPSK too; Enigma P03 FSK100 Waterfalls
AK10 per Hoka
GMDSS/DSC Maritime Selcall GMDSS DSC Waterfall
Japanese Slot Machine Mode is QPSK1500 QPSK1500 Waterfall
KEGURI DPRK 600 ARQ DPRK 600 Waterfall
MIL-STD-188-110A encrypted
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
M823/SC104 DGPS DGPS DGPS Waterfalls
NAVTEX A broadcast mode built on SITOR-B NAVTEX Waterfall
RDFT Mode used by HM-01;encrypted HM01 RDFT Waterfall
SITOR-A AMTOR MODE A some maritime, Egyptian use SITOR-A Waterfalls
STANAG4197 ANDVT encrypted ANDVT Waterfall
STANAG4285 encrypted STANAG 4285 Waterfall
STANAG4481 CRATT encrypted STANAG 4481 Waterfalls

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. Text is always encrypted and can't be read, though it can be decoded in many cases.

Mode or Description Synonym Notes Waterfall Page
Australian Forces 50bd/600bd
Chinese 4 plus 4 Modem last seen Sept 2020
CODAN last seen Oct 2020 CODAN Chirp Waterfall
Israeli Navy Hybrid 188-110 MOD HF Underground Mar 2020 Israeli Navy Waterfall
Japanese Mil 8-FSK encrypted- last seen Nov 2020 Jap 8Tone Waterfall
KEGURI DPRK 1200 last seen Jan 2019 DPRK 1200 Waterfall
MIL-STD-188-110 hybrid last seen July 2019
MIL-STD-188-110B last seen May 2020
MIL-STD-188-110C last seen Feb 2019
PACTOR-II FEC via I5-56578 Antonio Digital blog
PACTOR IV used in the maritime svc - last seen June 2020
Saab Grintek MHF50 MFSK Modem logs Nov 2020 MHF50 Waterfall
STANAG 4538 3G ALE last seen Dec 2019
STANAG 4539 MIL-STD-188-110B/C App C last Seen Oct 2019 MIL 188110C Waterfall
110C WB

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.

MFSK32 and 64 is currently being used by the Shortwave Radiogram program. Olivia and MT63 has been used in the past. See the Shortwave Radiogram Gateway for more information on this subject.

Mode or Description Synonym Notes Waterfall Page
AX.25 300bd FSK Packet Radio AX.25 Protocol Name based off X.25 Standards
PACTOR-I used in the maritime svc
PACTOR-II used in the maritime svc
PACTOR-III used in the maritime svc - often encrypted