Australian HF Marine Weather FAX Frequencies

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Australian Bureau of Meteorology HF Marine Weather FAX Frequencies

The Bureau of Meteorology broadcasts its marine weather HF radio services for high seas and Australian coastal areas from transmitters at Charleville in Queensland and Wiluna in Western Australia. Identifiers are VMC (for services from Charleville) and VMW (for services from Wiluna).

VMC (Australia Weather East) broadcasts for the following areas:

·         Coastal Waters areas off Queensland, New South Wales, Victoria and Tasmania.

·         High Seas for the Northern, North Eastern and South Eastern high seas areas.

VMW (Australia Weather West) broadcasts for the following areas:

·         Coastal Waters areas off South Australia, Western Australia and Northern Territory.

·         High Seas for the Northern, Western and South Eastern high seas areas.

Technical characteristics of Voice and Fax HF transmissions

Modulation: FSK (F3C)

Emission code: 3K00F3C

FSK Carrier: 1900 Hz

Shift: White +400 Hz, Black -400 Hz

Scan line frequency: 2 lines per second (120 lines per minute)

Scan line stability: Within 5 parts in 1,000,000

Index of co-operation: 576

Scanning line density: 3.8 lines per millimetre (96 lines per inch)

Picture format: Comprises start, phasing, picture and stop sequence as detailed below

Start signal: Carrier modulated for 5 seconds by alternate Black and White at a rate of 300 Hz

Phasing signal: 60 scan lines, each scan line comprising White level for 25 milliseconds followed Black level for 475 milliseconds

Picture signal: Line to start with 25 milliseconds White level, followed by one line of picture content uniformly occupying the remaining 475 milliseconds. This format to continue until entire picture content has been transmitted

Stop signal: Carrier modulated for 5 seconds by alternate Black and White at a rate of 450 Hz, followed by 10 seconds of Black level

SSB Receiver tuning frequency: (for a standard WMO facsimile decoder) 1.9 kHz below the published transmit frequencies

Tuning Tone: Most charts are preceded by 60 seconds of 'tuning tone' (white signal) to allow receivers to automatically tune and capture the chart.
The 'tuning tone' precedes the scheduled transmission time of a chart.
Some charts could not be preceded by 'tuning tone' as there is insufficient idle period preceding. To automatically capture these charts, set your receiver to wake up 2-3 minutes earlier and tune-in on the tail-end to the previous transmission.

For more information on Australian HF Marine Weather broadcasts. See: http://www.bom.gov.au/marine/radio-sat/marine-weather-hf-radio.shtml

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Page last revised 06 October, 2024