SITOR-A

SITOR-A | SITOR-B

SITOR-A

Frequencies	3 MHz,30 MHz
Frequency Range	3 MHz - 30 MHz
Mode	USB
Modulation	FSK
ACF	450 ms
Emission Designator	—
Bandwidth	350 Hz
Location	Worldwide
Short Description	SITOR-A (Also known as AMTOR-A) is one of two modes of SITOR, which stands for Simplex Teletype Over Radio.
I/Q Raw Recording	—
Audio Sample

SITOR-A is one of two modes of SITOR, which stands for Simplex Teletype Over Radio. Based on CCIRComité Consultatif International pour la Radio (Predecessor of the ITU-R) 476-4. It was formerly used to transmit maritime short messages, however the maritime industry is gradually moving away from using this mode in favor of PACTOR. AMTOR is a type of SITOR used by amateur radio operators.

SITOR-A has been seed with shifts of 170 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)., 400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)., and 850 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).. SITOR-A is most commonly used with 170 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). shift and 100 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second..

Samples

100 BdBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. 170 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). Shift

Frequencies

One of the biggest users of SITOR-A is not a maritime service - it's the Egyptian Embassy/MFA Cairo. The current version of the 2014 Digital Digest by Mike Chace-Ortiz (Spectrum Monitor editor) has an extensive description of this network. Also see the Utility DXers Forum on Groups.io for current frequency information

Video Examples

• Reception and decoding of a SITOR-A signal ("RCVB" Egyptian station )

Decoding Software

Hobby Level Software

• MultiPSK
• MultiMode (for Macs)
• Sorcerer
• TrueTTY

Professional Equipment/Software

• go2DECODE
• go2MONITOR
• Hoka 300-32
• Krypto500
• Wavecom W-Code
• Wavecom W-Spectra
• WinRadio Universal FSK Decoder
• Rohde&Schwarz CA100

Additional Links

• shoc Database: SITOR-A
• WAVECOM Database: SITOR-A
• Reading and Decoding the Transmissions of MFA Cairo (PDF) via UDXF website