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When off soundings, I convert weather faxes to charts in our chart plotting software (this also takes care of skew). This allows for instant geo-referencing and facilitates planning.
Great idea. Having said that, however, I find that I just use weather fax charts for the general overview. To look at the situation in more detail, I find that GRIBs work better for me, and they are automatically geo-referenced and can be loaded into our navigation system.
Can you recommend a “hardware” demodulator and does this allow the signal to come through without blasting over the SSB speaker?
I have been using moc.liasaliam@rehtaew‘s small TIF weather charts accessed via the sat phone. The size of the small TIF is nominally around 17 kb so to do what you do, i.s. slideshowing a series, might be a bit expensive at $1.75 or so a chart. But, when the WF is giving a poor or non-existent report, it’s a very good way to go and 100% reliable.
There are two versions of Weather Fax 2000, one with the hardware demodulator, and one that uses the computer’s own sound card for demodulation. The former is a lot better but more expensive.
And no, the demodulator will not prevent the signal blasting over the speaker. Our Icom M-700 has a switch that allows us to turn off the speaker. I was under the impression that all SSB radios were so fitted. I guess not.
Good point on getting the same charts over the sat phone when reception is poor. We have done the same from time to time, although, as you say, it gets pricy.
Are the UK weather faxes receivable from western Greenland? I was there last summer and, not realizing UK weather faxes covered areas farther north than Boston ones and assuming transmissions from UK would not make it over the mountains, never tried.
I found the Arctic Surface Analysis broadcast from Iqaluit to be quite useful, since it was the only weatherfax I knew of then that covered areas farther north than the ones from Boston. Not an easy fax to read (much data, all fine lines), but it does show all the weather systems in the Arctic.
Yes, the UK weather faxes are easily receivable from western Greenland, on the 8 MHz band, although it does depend on the time of day. The mountains would have no affect on this since with HF radio we are dealing with signal bounce from the ionosphere. Smart radio people who are into that kind of thing can calculate the optimal time and frequency for HF radio reception but I have to confess that I belong to the dumb “try it and see” crowd.
Receiving faxes at sea over SSB using either a soundcard or hardware demodulator delivers noise in the audio signal received as noise in the fax image. This can make reading the fax quite challenging. The Ham radio version of sailmail (airmail) has a huge selection of weather charts and forecasts available on request meaning that they can be acquired when propagation is good and/or when planning is at hand. These require a ham license, a HF SSB that transmits on ham bands, and a pactor modem. Gribs are also available by subscription – that is – regularly updated for an area specified in the subscription request. Ham bands are great for social networking and emergency communication. Licenses in US do not require morse code these days.
Hi Larry,
That’s true, but generally if the propagation and SSB installation is good enough for reliable pactor reception of a suit of files that big, it will also be good enough to produce legible analog maps via weatherfax. In addition, receiving a full suit (say 5 maps) will take a while at pactor speeds. I would guess at least an hour, and possibly a lot more, depending on how much, if any, they have been compressed by airmail. Not being a ham, I’m not sure what the protocol is for Airmail, but a sailor who was downloading daily maps via pactor would quickly exceed the rolling total of transfer time allowed by sailmail (90 minutes a week) and win no friends in the process.
(no editing function) The pactor modem faxes are noise free. Airmail Ham service is also free and includes email. Larry