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KC2UGV
10-21-2011, 12:41 PM
I saw FlDigi has xmit capability for WEFAX. Is there anywhere hams use this? It seems to be a duplicate of SSTV, but I figured it might be fun to play with.

Is there anywhere it's legal? Is it already in use?
ab1ga
10-21-2011, 06:10 PM
I saw FlDigi has xmit capability for WEFAX. Is there anywhere hams use this? It seems to be a duplicate of SSTV, but I figured it might be fun to play with.

Is there anywhere it's legal? Is it already in use?

I'd expect it's legal anywhere image transmissions are legal. As far as use, the sailing contingent might use them to forward maps to each other. The only real difference between WEFAX and modern digital SSTV transmissions is the frame format, which may be important to maintain.
KG4CGC
10-21-2011, 07:08 PM
HRD work on WeFax? What frequencies may I tune into WeFax?
ab1ga
10-21-2011, 07:29 PM
All the WEFAX services I remember worked at UHF, near 137 MHz; why anyone would want to transmit WEFAX on HF is beyond me.
KC2UGV
10-22-2011, 12:49 PM
HRD work on WeFax? What frequencies may I tune into WeFax?

Right now, I'm listening on 6.338.5 MHz; NOAA out of Boston.


All the WEFAX services I remember worked at UHF, near 137 MHz; why anyone would want to transmit WEFAX on HF is beyond me.

I guess the same reason people do SSTV on HF... Another mode to play with.
N8YX
10-22-2011, 01:33 PM
Fax transmission is legal for use in the amateur bands, though not a lot of folks utilize the mode these days. As Corey mentioned, you'll find a number of maritime-oriented Fax transmissions throughout the HF spectrum.

The old 137MHz VHF stuff is still in operation (IIRC...) but a lot of the satellites have been replaced by GOES, which operates around 1691MHz.
ab1ga
10-22-2011, 08:42 PM
The old 137MHz VHF stuff is still in operation (IIRC...) but a lot of the satellites have been replaced by GOES, which operates around 1691MHz.

Seems that WEFAX actually has two meanings. One, which I hadn't heard of, involved the direct transmission of weather fax imagery on HF by government and commercial stations.

The WEFAX I've always assumed is called GOES-WEFAX by NOAA, and is a retransmission of satellite imagery. The satellite data come down in S-band, then are processed and reformatted, sent back to the orbit and transmitted down in the 137MHz band. This allowed user to reuse existing ground equipment rather than buy S-band gear. Strange how time changes everything, if this were being done over today, I doubt anyone would bother with the retransmission, as ground equipment would be simpler than a GPS receiver.