Nasa Weatherman- any users?

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CJ13

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Thanks Vyv for pointing out the errror in my previous post so i'll try again.

Is anyone using a Nasa Weatherman??
Any comments on the usefullness or otherwise in the Med / Atlantic Portugal and Spain appreciated.

FYI we have a Navtex viewable thro a PC, which i don't find as usefull as a stand alone unit on permanent display.

Many thanks,
John
 
NASA Clipper Weatherman

I've had one of these for about 7 years.

Essentially it's an RTTY teletext on Deutscher Wetterdienst and the reports are as good as DWD make them.

Short-term forecasts are better from the local national Met Office but DWD was pretty good in the Atlantic.

The most useful are their long-term (5+ days) forecasts.

When you get into the Med, the size of the forecast areas make DWD less precise than most of the local national forecasts.

In terms of accuracy I'd rate MeteoFrance ahead of the pack and the Italians good for their small areas, but less good for meteorological competence. (Their Air Force regurgitate the GRIB without any attempt at improvement)

I've found Posiedon (Greek) pretty inaccurate and prefer to use the GRIB file downloads and derive my own weather forecasts.

Least useful are the forecasts posted on Navtex, usually late and imprecise as well as inaccurate.

Summary - a good additional source of met data, but needs to be used in conjunction with at least 2 other sources to achieve reliability.
 
I've also had one for several years and the 5 day fcst is relevant to passage planning. But I haven't found the reception to be very good, in harbour anyway. Obviously if you follow them the 4th and 5th day are always eventually updated, so it's a really only reliable for 3 days.
I do find the Split navtex pretty accurate and I listen to the Italian VHF for comparison.
I always prefer stand alone units.
 
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I didn't have mine in the western Med, only in the Aegean. The signal is very erratic despite trying the antenna in various positions all around the boat and topsides. Sometimes we receive a couple of transmissions per day but other times nothing. One problem is that if the initial signature signal is not received, the recording does not start. It is possible to watch the information coming through but you need a quick pencil!

The other problem is that the information is targeted on very few locations, in the Aegean one somewhere west of Samos and the other down by Crete. A good deal of interpolation is required if you are nowhere near them.

Having said that it is a reasonable source of information for trends up to five days ahead, difficult to obtain without an internet connection.
 
I've used mine in the western med

I like

1. It draws hardly any current and can be left on all the time
2. Forecasts can be held in memory and consulted later when convenient
3. Simple tabular forecasts -easy to interpret
4. You can get a forecast at least once most days

I don't like

1. The signal can be unreliable depending on atmospheric conditions et al
2. You have to scroll through several areas to get the forecast you want even with the filter set


I find that its great when away from the internet (when I use Ugrib by preference ).

Would I buy another one? On balance, definitely!

Hope that helps
 
Also had one of these for 5 yrs or so now. Firstly I agree with the above comment that it´s very economical on current and here in the Baleares the signal is fine although there´s serious interference in port. However it´s not accurate - it basically gives a rough guide of any changes. Before making a passage I always consult 3 or 4 different forecasts eg windfinder, windguru etc (internet obviously), but the weatherman I would only use as a back up. On too many occasions has it vastly over-estimated the wind strengh eg often, especially in summer a force 5 is regularly a force 6-7 which may be the difference between staying or going especially if it´s "on the nose". Very annoying and often unreliable over-estimations.
 
I recon the info from RTTY Germany is useful, the 5day over estimates at first but warns of winds to come and from where, helps to plan my week ahead. The short range forecast i have found good.
The main drawback for me is the Weatherman's reception compared with a shortwave radio and computer. The active antenna on mine is useless, really useless, like all i get is a row of stars come up on screen with the occasional letter or number but when wired to my uninsulated backstay via a capacitor, it improves greatly. Not perfect but worth having on board.
 
Happydaze said:
Hi Vyv

The 75 ohm coaxial is ran to the back stay from the unit and the central core is connected to the back stay wire through a 0.1mfd ceramic capacitor to stop the 12 dc power. The central core is live to power the active antenna when fitted.
Click to expand...

Am I right in understanding that if you had an insulated backstay then you would not need the capacitor?

I have an unused insulated backstay (no SSB at present). Can I connect up to it to improve reception - or is it not as simple as that?
 
I have found my weatherman to be total cr*p due to reception problems. I got a few basic messages around the English Channel, these dwindled on the way to the Med, then from S France to Greece, absolutely nothing (in spite of playing with the settings etc.).

I met someone who had previously had the same problem, but changed the antenna on Nasa's advice. Apparently if you get moisture in it, the antenna corrodes in 5 minutes - mine has white powdery deposits all over it and scraping them off didn't work.

I was about to bin it when I read this thread. So does this mean just soldering the central core (with a capacitor anywhere in the line?) to the backstay? What do you do with the screening? I have no backstay insulation, does this matter? Any other advice?

Otherwise, I wouldn't even give it away - total waste of space.
 
Hi jb267

I have left my active antenna in place on the rear gantry and connected to the weatherman. From inside the active antenna i have soldered a capacitor to the central core wire on the PCB then soldered a single wire from other leg of the capacitor to my uninsulated backstay. The wire is secured to the backstay with a tiny jubilee clip. The capacitor is there to allow the signal through but stop the 12 volt dc reaching the rigging, so put it in-line where it suits your installation.
 
Hi Vyv

You mentioned the problem that if the initial header part of the message is missed the Weatherman doesn't store the message. I contacted NASA about this and they told me you could press one of the buttons to force it to record the message. I think its the Enter button but the details are on the boat and I'm at home. This info isn't in the user guide. I think this works for any message, even if its one you've programmed not to be stored.
 
steve123 said:
Hi Vyv

You mentioned the problem that if the initial header part of the message is missed the Weatherman doesn't store the message. I contacted NASA about this and they told me you could press one of the buttons to force it to record the message. I think its the Enter button but the details are on the boat and I'm at home. This info isn't in the user guide. I think this works for any message, even if its one you've programmed not to be stored.
Click to expand...

That's very useful to know, thanks. I'll give it a try. Who knows, with my antenna connected to the backstay and pressing Enter as required I might even get it to work something like reliably.
 
Hi John,

I have used a 'Weatherman' since leaving the UK six years ago. I have found the unit to be very useful, especially the five day forecast which includes wave heights. It has often been my first indication of the approach of poor weather. All the sea areas are shown with their lat/long and I plot those that are of interest to me, so that I can form a mental picture of what the weather is doing. Invariably I seem to end up somewhere between two or more areas. Now that I am in the Eastern Med I have noticed a deterioration in reception, so I recently changed the aerial from the Nasa supplied unit to the use of my insulated backstay as per the previous posts. Nasa were very helpful in supplying me with a wiring sketch and appropriate resistor. I now have much improved signal strength.
It is also worth experimenting with the different frequencies, which depending on location and time of day give the best reception.

Steve White.
Rassy Lady
 
From my experience in the Eastern Med, generally one got better and more reliable weather forecasts from the INMARSAT C SafetyNet messages (the offshore equivalent of Navtex), albeit this was a few years ago and things have improved since then.
As a lot of Med weather is from local, thermal winds (sea breezes, Mistral etc) it is worth looking at something like SmartMet (http://www.smartcomsoftware.com/smartmet.html) - as well as GRIB forecasts, this also offers satellite images and current weather reports, which helps overcome the limitations of GRIB forecasts in predicting small, local weather systems.
 
capacitor of 0.1 mFd in series with inner conductor of 75 Ohm coaxial cable to backst

Hello!

I have just bought the NASA Weatherman for receiving. It seems to be a very good device.
(I also own since years a NASA Target Navtex, and since last year a HF3 receiver, all great devices so far ! (easy to use, low power consumption).)

In your manual of Weatherman http://www.nasamarine.com/images/file/weatherman.pdf (page 4 of 16) is written, to include a capacitor of 0.1 mFd in series with inner conductor of 75 Ohm coaxial cable to backstay antenna, to block DC supply from the receiver.

My question:
Do you mean:
a) 0.1 milli Farad capacitor
or
b) 0.1 micro Farad capacitor ?

Many thanks in advance for your advice !
Sincerely
G.
 
0.1 mFd milli or micro --- answer from NASA: 0.1 micro Farad

Hi!

Thanks for your quick reply!
I had sent same question to NASA, and they answered also within minutes! Very good support!

But their answer is different, they wrote me clearly 0.1 micro Farad.

Because 0.1 micro Farad is cheap part, I bought it already yesterday from local electronics parts shop.
And it was the local dealer, originating from Netherlands and living long time in Germany, who brought my attention to this question.

I wanted to order 0.1 milli Farad like you did, because in Germany m means clearly milli = 1/1000, according to the manual 0.1 mFd , and micro would be shortened as something like Greek u "mü" = 1/1000000.

But the local dealer asked me, what I would want to do with high capacity of 0.1 milli Fd, unusual, he does not have 0.1 milli Fd, but 0.1 micro Fd.
I explained to him about antennas, DC supply stopping, and he answered, then 0.1 micro Fd would be very very likely the correct thing.
Because it would just be about stopping the DC voltage. And he guessed, it would be a USA-built device or USA-manual.
Well, I said to him, Made in England, and I think, his guess was quite good!
Because I think, that maybe abbreviations like m=micro? might be the same way in UK and USA, but sometimes there are differences in language, I know !!

But you make me feel a bit unsafe again, because I think, you are native speaker, you seem to know, what you do and got a 0.1 milli Fd.......

But I got confirmation from NASA about 0.1 micro Farad 2 times, and also the local electronic dealer seemed to be sure, that 0.1 micro Fd is appropriate for the usage. He said also, that the exact value of capacitor does not matter, because of just stopping DC voltage.

Well nevertheless, nice to hear from you, that 0.1 milli Fd work well,
so if my antenna coax cable with 0.1 micro will not work well, (and I exchange with 0.1 milli Fd with better success) I will let you know here , maybe in April-May I am at the boat!

What I can just advise anybody about antennas and LW/MW/SW receivers,
a 7-8 m backstay will work very well, even if ungrounded to keel or such, eg. just fixed at glassfibre hull, although the backstay is unisolated, means: backstay connected normally to rest of rigg like forestay and mast!
At least, this is worth a simple to carry out trial, if other antennas result only to bad results.

Further hints from my practical xperience, partly already included in good NASA manual:

- backstay, even as it is, unisolated, can be very good antenna, at least for 4583 kHz or eg. 177 kHz or 1269 kHz, my receiving even well quite nearby to Hamburg, being in Baltic sea, also already more away from Hamburg, in Finland, Helsinki, and in between :)

Things, which destroy the radio signals:
These should be switched off during receiving!
- modern 12V battery chargers
- ignition coils, like (outboard) motor, (benzine)
- even GPS chart plotters could be unclean
- fridge: (cooling/freezing devices)
If you have receiving problems, try simply by switching off your devices on board, one after another, or better all (then switch on 1 after the next and see, when signal is bad again...
But it might creep in over 230V power from land,
or maybe your neighbour in harbour has motor, charger or fridge on.....
 
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