Thursday, July 24, 2008


One thing in radio I have always wanted to do was to decode radio faxes. Basically they are just like your standard phone fax but broadcast over the HF airwaves. It is possible to also download the raw map data directly from the orbiting satellites, but HF Fax is much easier to receive with your standard HF rig. To receive HF-FAX, all you need is the ability to decode PSK31 using your radio/computer. From there, you can use a fax decoding program and you are set. I happen to use Multipsk which is a free program.

All of the HF-Fax transmissions I have come across originate from the NOAA. Essentially, they are weather maps for marine vessels out in the open ocean. If you think about it, if a vessel cannot afford to pay for satellite internet service, they can obtain free weather charts via HF fax. I am simply receiving these free faxes too even though I am sever thousand miles from the nearest ocean.

Attached is an example of a fax I received today. I still have some sound card tweaking to do which I believe is the cause for the phase shifting in the image. Let me know if you want more information and I can post some additional internet sites I have seen.

73 Joe N0NS

nubi78 {AT} yahoo dot com

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