NASA Clipper navtex - brief guide on how to set up

[jbweston]

Over the last few months I've had a number of people say to me in person or here on the forum they are having trouble getting their NASA Clipper navtexes set up properly. I'm no great expert but in response to a request in someone else's thread I volunteered to provide an Idiot's Guide. So here it is.

Note this advice is specific to the NASA Clipper navtex. Also I have no connection with NASA, I'm just a satisfied user who found it a bit complicated when I first installed it on my old boat, but found once set up it was a great bit of kit and I wouldn't be without it.

First the big picture, for those who like that:

1. First make sure it's working OK - display lights up and receiver able to pick up something from somewhere.
2. Then make a distinction in your mind between the features and drawbacks of the navtex system (same for any receiver) and the specifics of how you get the Clipper to do what you want.
3. Program / setup the Clipper to do what you want.

Taking these in turn . . .

 

[Bilgediver]

First the big picture, for those who like that:

1. First make sure it's working OK - display lights up and receiver able to pick up something from somewhere.
2. Then make a distinction in your mind between the features and drawbacks of the navtex system (same for any receiver) and the specifics of how you get the Clipper to do what you want.
3. Program / setup the Clipper to do what you want.

Taking these in turn . . .

Ok.....Done that....Now waiting for the serious bits

 

[jbweston]

1. Make sure the Clipper receiver is working OK

Difficult to give generic advice because, if it isn't working, there could be a number of reasons. See my post on diagnosing problems here:
http://www.ybw.com/forums/showthread.php?p=2528654#post2528654

Note the original poster there found what looked like a receiver or aerial problem turned out to be a programming problem. The important question is, is it receiving anything - even useless messages from foreign stations? Because if so, you've completed step 1.

When properly set up the Clipper recieves everything but drops (doesn't retain) the stuff it's been set up to ignore. Tha means when there's a transmission happening the received text appears character by character along the bottom of the screen. If the message is from a station and of a message type that the receiver has been told to keep, it scrolls it up the screen. If not it still appears at the bottom but gets deleted as it 'drops off' the end of the line. This is a useful diagnostic, because you can wait until your strongest station is scheduled as transmitting and see if it's coming in along the bottom. If so, the receiver's working and you can safely move on to step 2 . . .

 

[jbweston]

2. Distinguish between the features of the navtex system and of the Clipper receiver

The key bits about navtex are:
- There are two fequencies, and the Clipper can pick up only one at a time. Which do you want?
- Which station(s) do you want to receive?
- Which message types do you want to receive?
- What times do your chosen stations transmit your chosen message types?

Rather than repeat what others have written better than me, try the following sources:

- Reed's Almanac weather section - station locations, details of what is on each of the two frequencies and schedule of transmission times.

- Frank Singleton's navtex page http://weather.mailasail.com/Franks-Weather/European-And-Mediterranean-Navtex-Schedules gives excellent information and advice about all this.

- Martin Stubbs' notes http://www.users.zetnet.co.uk/tempusfugit/marine/navtex_notes.htm - a few years old, but again plenty of information.

Once you know which frequency, which stations and which message types you want and when they are transmitted, you're on a roll. If in doubt, why not start by choosing International frequency (518 kHz), and cast your net wide - all stations and all message types. You can cut back to what you really want once you can see how everything is working. Once your are properly set up you don't want to be awash with a sea of information, but to start with it might be comforting to see it all streaming in.

Note reception can be a bit variable as navtex technology is pretty basic - it's a combination of the medium wave transistor radios of my youth and an electronic version of the old football results teleprinter or telex. However, basic doesn't mean bad. Navtex is part of the GMDSS, and so governments are committed to keeping the clockwork running rather than our having to rely on some dodgy foreign Johnny commercial operator who might forget to transmit because his assitant is off sick or there's no R in the month.

It is worth finding out what neighbouring boats can and can't receive, because (life being like it is) your reception is unlikely to be better than theirs, and might be worse. So not getting messages might be because of poor reception in your current location. Also reception is better at night, even though the stations are supposed to bump up transmitter power in the day to compensate.

Now you can go on to Step 3 . . .

 

[jbweston]

3. Program / setup the Clipper

For detailed instructions, I don't think I can do better than the NASA manual. It used to be available for download from the NASA website, but it doesn't seem to be there any more. It's on various file-sharing sites but for ease of access I've uploaded it and you can download it for free from here: http://www.mediafire.com/?crw44ymj5nt

TIPS:

- Don't forget the Clipper can receive only one of the two frequencies at a time, so you have to choose. However, you can (and have to) program the stations and message types separately for each frequency - then choose which frequency you are going to have operational. Most of us will want International (518 kHz).

- You can't turn off some message types and you'll have endless fun trying to do so without success until you realise that you just can't do it.

- I found the most difficult bit to remember without the manual in front of me was how to move out of the 'receive messages' screen (called Standby on the Clipper) to get into the various setup screens. You do it by a long press of the Enter key (pressing it and holding it down for few seconds). After that all the instructions appear on screen and you probably don't need the manual.

- Finally, when you put the set into Standby, double check it's listening on the right frequency - see message at bottom left of its screen.

So that's it. Hope it works for you.

 

[luke1000123]

Is there a button to switch the navtex off, or does it simply stay in standby mode all the time

 

[LittleSister]

Is there a button to switch the navtex off, or does it simply stay in standby mode all the time

If I remember correctly, like much NASA gear it has no internal on/off switch. If the supply is on, it's in normal receive mode (by default). You would need an external switch to turn it on and off.

Manuals for NASA instruments, including Navtex, here:
Manuals - Nasa Marine Instruments

 

[STATUE]

Over the last few months I've had a number of people say to me in person or here on the forum they are having trouble getting their NASA Clipper navtexes set up properly. I'm no great expert but in response to a request in someone else's thread I volunteered to provide an Idiot's Guide. So here it is.

Note this advice is specific to the NASA Clipper navtex. Also I have no connection with NASA, I'm just a satisfied user who found it a bit complicated when I first installed it on my old boat, but found once set up it was a great bit of kit and I wouldn't be without it.

First the big picture, for those who like that:

1. First make sure it's working OK - display lights up and receiver able to pick up something from somewhere.
2. Then make a distinction in your mind between the features and drawbacks of the navtex system (same for any receiver) and the specifics of how you get the Clipper to do what you want.
3. Program / setup the Clipper to do what you want.

Taking these in turn . . .

4 Years ago. I purchased a NASA Navtex +- the then special new aerial ( Can't remember name).

On swinging mooring in middle of Portland Harbour - very poor performance (must surely be how I set it up!?

On berth in Brittany same as Portland.

BUT, in the middle of the Channel, day or night, excellent.

Lesson, when in port, get weather from your mobile.

 

[franksingleton]

4 Years ago. I purchased a NASA Navtex +- the then special new aerial ( Can't remember name).

On swinging mooring in middle of Portland Harbour - very poor performance (must surely be how I set it up!?

On berth in Brittany same as Portland.

BUT, in the middle of the Channel, day or night, excellent.

Lesson, when in port, get weather from your mobile.

Correct. NAVTEX is intended for use from the fairway buoy to about 200 miles out to sea. It may receive in harbour or near the coast but much depends on local screening and interference. There is little difference in the reception between the various sets. A good aerial is essential, low down usually better than high up. Differences between sets are usually more build quality, display quality and features.

 

[LittleSister]

Lesson, when in port, get weather from your mobile.

I can remember dreaming of having a Navtex, when getting a local marine weather forecast might well involve getting togged up, rowing a mile and and half in the pouring rain, then walking quarter of a mile in the rain, and then throwing coins in the telephone kiosk slot at a rate of knots, while trying to hear the poorly recorded and reproduced Marinecall (?) forecast dictated in very high speed bursts between inexplicable pauses, having to listen (and pay) again to get the bits I'd missed, and running out of coins before getting to the crucial bit again. Then the reverse journey in the still pouring rain to a small boat with nowhere but the tiny open plan cabin to hang wet oilies.

Those were the days!

(Dandy Hole and St. German's, since you ask.)

 

[Sgeir]

Best keeping them turned on permanently. At least one of the NASA models has an internal battery and, as I found, switching it off over the winter didn't do it any good........

 

[coveman]

Best keeping them turned on permanently. At least one of the NASA models has an internal battery and, as I found, switching it off over the winter didn't do it any good........

True, and if it has been off for a long period it can take 12hrs or so before there is any sensible display on the screen - it may just show a load of haphazard symbols for a while.