WEFAX

Meteosat WEFAX - WEFAX

WEFAX

Frequencies	3 MHz,30 MHz
Frequency Range	3 MHz - 30 MHz
Mode	USB
Modulation	FM
ACF	—
Emission Designator	F3C
Bandwidth	3 kHz
Location	Worldwide
Short Description	Radiofax (Also known as Weatherfax, HF-FAX, WEFAX, and Weather Facsimile) is a slow scan analog image transmission mode used for the transmission of weather charts and meteorological reports.
I/Q Raw Recording	—
Audio Sample

WEFAX (Also known as Weatherfax, HFHigh Frequency (3-30 MHz)-FAX, Radiofax, and Weather Facsimile) is a slow scan analog image transmission mode used for the transmission of weather charts and meteorological reports. The only station known to be sending newspaper articles (in Japanese) is the Fukushima Fisheries service in Japan. Their schedule can be found here (courtesy of the UDXF) as a PDF.

WEFAX was originally developed for satellite usage, but has gained usage in the HFHigh Frequency (3-30 MHz) bands in the past decades. Satellite WEFAX use can be seen at Meteosat WEFAX.

Format

WEFAX's format is a derivative of the Automatic Picture Transmission (APT) originally developed for transmission from the polar satellites of the USA.

WEFAX has 60, 90, 100, 120, 180 and 240 LPM (Lines per minute) speeds, and two IOC (Index of Cooperation) modes, IOC 576 and IOC 288. Most weather forecasts are sent in IOC 576.

WEFAX frame format

Signal	Duration	IOC576	IOC288	Remarks
Start tone	5s	300 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	675 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	200 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz). for colour fax modes.
Phasing signal	30s			Black line interrupted by a white pulse.
Image	Variable	1200 lines	600 lines	At 120 lpm.
Stop tone	5s	450 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).	450 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
Black	10s

Samples

Speed Modes

120 LPM	240 LPM

Northwood

Intro	Fax	End of Trans.

Frequencies

• Typically around 3 MHzMegaHertz (MHz) 10^6 Hz to 16 MHzMegaHertz (MHz) 10^6 Hz. See here for Yachtcom UK Weatherfax frequencies.
• NOAA Worldwide Radiofax Guide
• USCG Marine Weather Broadcasts Note: Click on the USCG Radiofax link

Decoding Software

Black Cat Software

• Black Cat HF Weather Fax (Windows and macOS)
• Black Cat Weather FAX (Android)
• HF FAX Decoding (IPhone / IPad / IPod Touch / Android)

Other Software

• CocoaModem (for Macs)
• Fldigi
• JVComm32
• JWX
• MixW
• MultiMode (for Macs)
• MultiPSK
• RxPlus
• SDRUno WeatherFax Plugin
• SeaTTY
• Sorcerer
• Wolphi Weather FAX
• Zorns Lemma Page is in German

Professional Equipment/Software

• go2DECODE
• go2MONITOR
• Radiocom6
• Hoka 300-32
• Krypto500
• Wavecom W-Code
• Wavecom W-Spectra
• WinRadio Advanced Digital Suite

Video Examples

• HF Weatherfax with RTL SDR (RTL2832) in Direct Sampling Mode, SDR Sharp and FLDIGI
• Kyodo News HF FAX with RTL SDR (RTL2832) and Nooelec Ham It Up Upconverter, SDR Sharp and FLDIGI
• HF Fax Decoding (Northwood)
• Receiving NMC Weather Fax on 8682.0 kHz

Additional Links

• WAVECOM Database: WEATHER-FAX
• WAVECOM Database: PRESS-FAX
• RadioScanner.RU HF-FAX
• Radiofax Wikipedia

Additional Images

Kyodo News sample received via Radiofax Wind forecast chart from Northwood, decoded from transmission. Press fax, 1991 Germany. Image decoded from recording. Meteorological chart from Deutscher Wetterdienst. January 16th, 1991. Image decoded from recording.