Help! weather fax or Navtex??

[Guest]

Hope someone can help out there, I am planning an off shore trip & am currently kitting out my yacht(26').￾@I can't decide between a weather fax of a Navtex system, can anyone make a recommendation or point out the pro's/con's of each?

I will be sailing from the far east via S.E asia & the red sea to the UK.

cheers

 

[zvidoron]

You will be sailing through some of the world's worst piracy infested waters. Forget Navtex, just install a couple of machine guns...

 

[vyv_cox]

I have no experience of the integral weather fax receivers, but I do know they are not cheap and of course do nothing else, unlike a laptop based system. About a year ago someone on this BB said they regretted buying theirs, but that's all I know.

I have purchased an Icom PCR1000 and loads of software and PCMCIA cards to receive weatherfaxes on a laptop. It has been notably unsuccessful and I have almost given up trying. The complete system has cost me more than 500 pounds, plus the laptop of course, not a good investment. If I was starting again I would be looking for a way to use Internet forecasts, the telephone medium then being dependent upon how far offshore you are going to be. Satellite phone systems for blue water are proliferating and the cost seems to be coming down all the time. Satcom amd Inmarsat seems to be available for between 2000 and 3000 pounds and Iridium will surely be making a cheaper return soon.

Contrast all that with a NASA Navtext Pro at about 250 pounds. You don't get a chart but anywhere in Europe you get a detailed forecast that enables you to construct your own. Can't speak for further afield but maybe others can help.

 

[tony_brighton]

As I recall, Piracy warnings are a Navtex message type - might be worth having. Maybe more important than the ice warnings.

 

[Twister_Ken]

Navtex range and duration

NAVTEX is approx 300 miles from transmitter. If you are going to be offshore Navtex will often be out of range, and fax would be better.

Also navtex (at least in UK waters) just gives a 24 h forecast, which is fine if you are within a few hours of shelter. But offshore you need to see weather patterns developing. Faxes (or Internet sources) let you do this, maybe with enough notice to get yourself on the favourable (or least terrifying) side of weather features.

 

[vyv_cox]

Two comments

UK Navtext stations Niton and Cullercoats broadcast forecasts for the next 24 hours, the following 24 hours and the outlook for the three days after that. The first two twice per day and the latter once. I think that Corsen do the same from France. Personally I never believe a forecast of five days ahead, so I'm as prepared as it's possible to be. I don't know the situation from further afield.

If I set "stations" to receive all, I regularly receive from Iceland, Norway, Croatia, Spain, France, Ireland and sometimes from Haifa in Israel. I'm in Holland, so signals are arriving from much further than 300 miles. That may be the official range but in practical terms it is far better.

 

[Guest]

Re: Two comments

But then again I had problem picking up Cullercoats from any further than the Frisian Islands.

 

[Guest]

The two cheapest methods for picking up weather information are:
1. Iridium phone which is now available for around USD 1,000 and includes marine antenna, charger, holder and data cable. Voice calls are $1.50 a minute and data calls £0.88 a minute. There is also SMS. Don't forget the laptop!
2. Shortwave receiver with modulator and software which will set you back at least USD 1000. Still needs a laptop.
For safety reasons I would go with both options. My only question -- why go to the UK?

 

[Guest]

Almost forgot, with the second option of the shortwave receiver you can receive weather faxes and NAVTEX -- if you are prepared to put the time in to figure out how.

 

[Bergman]

I think its clear that Weatherfax is your best bet. If you already have the laptop all you need is an halfway decent receiver say £200 in UK. The software is available free off the Internet.

All you need to connect the two is a simple audio cable with a jack plug on each end. Connect the audio(headphones) out of the receiver to the mic socket on the 'puter and away you go.

In between you can listen to BBC World Service as well

 

[vyv_cox]

If only it was so easy!

Unfortunately this is a vast oversimplification. I have spent two winters trying to receive even one weatherfax, without notable success. Free downloads are more or less what you expect, less than perfect. For better arrangements you need a demodulator that only plugs into a USB or a serial port. If using an old laptop without a USB you may need an extra serial port, via a PCMCIA card. These are as rare as hens teeth. Another alternative is to install a new sound card, again with all sorts of associated problems of compatability with existing software.

As I think I have suggested above, if going this route buy from a dealer and see it actually working on your machine, not the demo version, before parting with any money.

 

[Bergman]

Re: If only it was so easy!

But Vyv it is that easy.

I have done it.

Its working here on my desk.

Sure the software is not the best in the world but it produces a clear fax of whatever is sent. All that is lost is a banner asking for money not have the banner on the output.

The sound card does the demodulating and the computer does the signal processing. Using these techniques for receiving Fax is normal practice now, I wouldn't dream of buying a fax machine. My phone line connects to the 'puter and I use Quicklink to send and receive. I thought everybody did nowadays.

I am a simple person. The fewer bits involved the fewer things to worry about, tinker with and go wrong.

I have used this HP computer, a Dell laptop and an IBM Thinkpad. All worked fine

The sister programme to the one I use will decode Navtex and RTTY too so you can have both systems.

Navtex is actually better than the NASA machine since the receiver is more sensitive.

 

[vyv_cox]

Phone line?

I thought we were discussing Weatherfax? It is transmitted on short wave radio and can be received by SSB. Phone lines don't reach to my boat.

 

[Bergman]

Re: Phone line?

Please read more carefully

The phone line is here in the office, used for normal commercial landline fax.

I quoted this as an example of using a computer to demodulate a fax transmission.

The same computer with its audion input connected to a SSB receiver will receive Weatherfax Navtex RTTY and several other forms of data transmission which are transmitted on SSB.

It will even decode morse if it is well sent.

The only equipment needed is an audio cable that connects the output of the SSB receiver to the Audio input of the computer - Nothing else.

If you are really ambitious you can get a second cable and transmit on these modes.

I have worked stations all over the world on PSK31 and RTTY using this equipment.

 

[vyv_cox]

Re: Phone line?

It's not the computer that's the problem. Even my old W95 laptop will receive good fax signals such as arrive down hard wires. The problem lies between the the RTTY transmissions and the computer.

When Bracknell was still transmitting, they were on air almost constantly, broadcasting charts of every conceivable meteorological variable, pressures, temperatures at a range of altitudes, iceberg positions, 24, 36, 48, 72, hour forecasts and very many more besides. Most of these take about 15 minutes to arrive in full. There is normally no means of telling what is being received unless either the header or footer is legible.

I have been unable to find any timetable showing when the ones of interest to me are broadcast. The only alternative seems to be to leave reception on all the time, not a realistic proposition.

Each transmission contains start and stop information that tells the computer to commence a new page. Despite having bought what I was told was the best weatherfax software available, it has never detected these signals.

Control of the IcomPCR1000 receiver is achieved by a display on the laptop screen. This seemed to be the ideal one to purchase since I had no intention of using it other than with a computer. However, the weatherfax software also needs to be controlled on screen, particularly for tuning by sound to obtain the precise frequency and stage of transmission. Xaxero do this by letting its software take over the Icom function. (Note that Xaxero and many competitors recommend the Icom PCR1000) I have never been able to do this because of a variety of conflicts, hardware problems, etc. My laptop has one serial port but two are needed, one for the Icom output and one for its tuning, so I was forced to purchase a PCMCIA card with serial connectors. Even then I could never persuade it to function correctly. The dealer I used had no ideas, he sold the kit but knew little about it. His only suggestion seemed to be to dump the Xaxero and buy something else. Xaxero themselves were not terribly helpful.

I have now become totally despondent about the whole process and it is more than a year since I tried to receive anything. I am now certain that at Iridium rates it would be far more logical to call your ISP from anywhere in the world and use Internet forecasts.

 

[Bergman]

Re: Phone line?

Vyv

I think I appreciate your problem.

If you wish to send me an E-Mail I may be able to help.

I would advise caution over Iridium. It may be relatively cheap now but it is not a realistic price and it is most unlikely to be sustainable. Only if they attract an enormous amount of traffic will they be able to maintain these sort of call charges.

Also remember that the bit rate on Iridum is very low for Internet use and it will take a long time to retreive information from the net, time that you have to pay for.

I think the greatest advantage of using a SSB receiver is that it is so versatile.

At the twidle of a knob I can receive Weather fax from all over the world, Navtex, RTTY, 2182kHZ calling channel, Coast station forecasts, Even in a dire emergency, Radio 1.

All for free!

Stick at it it is worth it.

 

[Bergman]

Re: PS

I may be gone for some time.

Now the good weather has gone away we are off sailing.

HA! that rain and wind.

Cheers