We use the ICS Nav6 - not the cheapest, but easy to install (I think installation procedure will be more or less the same for all types) and it has a very large readable screen. This type can recieve 518 kHz and 490 kHz, though not both at the same time.
You could also go for the Nav6plus: it doubles up as an intrument repeater, working with NMEA0183 input, and can recieve both frequencies at the same time.
I've got a Nasa Pro Plus. Works just fine, is easy to install and doesn't need any paper. The only downside is to go between the two frequencies (local and international) requires a manual flick of a switch on the wire going to the aerial. This is easy to forget.
My advice would be to go for a paper Navtex, at least if you intend to use it for offshore use. This is contrary to the advice given in the rather superficial recent tests in the yachting mags! I have the ICS 4, which is excellent.
The main reason for paper is that it's much easier to use at sea. Programming, scrolling through, fiddling with buttons on etc. an LED one at sea doesn't bear thinking about unless you have the world's strongest stomach. The LED ones are (presumably) fine if you don't intend ofshore use and all you want to do is pick up forecasts and nav warnings while at anchor. Paper you can tear off and read at your leisure in the cockpit without any fiddling scrolling, button pushing etc.
Paper also has the advantage that you can programme it to print out your position from the GPS every 15/30 mins/hourly whatever.
The disadvantage of the paper one is (obviously) that you have to buy paper for it. My first box has just run out after 3 years, and I got a new one for £25. ie. it costs me about £8 per annum with pretty frequent usage.
Installation is straightforward, but I should imagine it's pretty much the same for any Navtex.
We use the Nav6 plus too. Very good bit of kit, and the instrument repeater function is excellent - Everything to hand in one instrument at the chart table. One feature not widely published is the log function. You can set this to record position, speed, wind stregnth/dir etc. Very good for updating your paper log at the end of the trip.
I fully support simonc's view. I have the same setup. The ability to have a paper printout giving your position, speed and track at regular intervals is an excellend added bonus, particularly if you are sailing single handed. If a weather forecast comes in while you are sailing in rough conditions it is easy to tear off the paper and take it into the cockpit to read.
Maybe a silly question - but how well does the paper/ink stand up to getting wet - is it fairly tolerant of water, or does it fall apart at the first drop?
Hmmmm....would go for the Nasa ones, possibly their latest or at least a Nav Pro. I definately would not go for the paper roll ones. Had a ICS Nav 4 on the last boat and it drives you bonkers. It has a tiny memory and then spews out reams of paper all over the boat when the memory is full...also you try fitting a new roll of paper in any kind of sea!
Current boat has Nasa digital screen and no you don't have to reprogramme it. You only set it up once to receive stations and messages and then as you move into each transmission area it picks up the appropriate stations.
Best bet of course is Nasa's new digital screen system which receives RTTY messages from Hamburg. But I don't think its commercially available at the moment.
The beauty of Navtex is that the Dutch and Belgiums put out gale warnings for Force 7 whereas the UK stations don't unless its a Force 8....strange that...when its blowing that hard who cares whether its a 7 or an 8!
I've got a set nobody's mentioned yet - the Furuno NV300. Installation is as easy as any set , it is dual frequency , the switch being done via software and is very easy to set up filters. All in all dead easy to use and so far reliable. It also acts as a GPS repeater.
Never had a problem with paper degredation. The paper has a shiny surface and it is a thermal printer so there is no ink. The roll is always left in the machine over winter months with no problems from the damp.
I think the reference is to the Nasa Weatherman, see PBO, May, p.103. It's been on sale in Germany for a year, and I believe its ability to chuck out forecasts in German is obviously a big selling advantage there as against say a Navtex.
The North German Weather Service used to be repeated by a Dutchman on his web site, and its really useful feature was a 5 day forecast, but its either closed or moved and I haven't been able to find it for ages.
I think it will be a valuable tool when it comes out here, but if it's going to be the same price as a Clipper Navtex, (which is suggested in PBO), then I think it's of doubtful value. We have so many sources of weather in English. However, if it actually is the price of (say) a Clipper Depth Sounder or a basic Target Navtex then I think it has a future. Particularly the five day sequence, which our Government does not let us have, really makes Cross Channel weekend will we / won't we decisions much easier.
I'm surprised you found that the ICS 4 spewed out loads of paper when memory was full. I haven't had that problem. It has always just printed out messages as they are received.
I suspect that you may have put the unit on auto station selection, or selected too many stations, or too many categories of information. As with any Navtex receiver, it is important only to select the station that you require and the categories of information that you require, otherwise you will be swamped with information (and, in the case of the ICS 4, paper!)
I have found that the best way to use it is to select only one or two stations, and only a minimum of categories you really need. No matter what type of receiver you have, you don't want to be swamped with information.
Changing rolls at sea hasn't been a problem, but I find I only have to change once every few months. Also the paper gives a day or two's warning that it is getting towards the end, so unless you're at sea for several days you can always pre-empt by changing before you leave.
Having said all that, I think the LED ones are better if you only intend to use them at anchorage and not for offshore use. The rather depressing thing is that the yottie magazine reviews didn't even try to skim over the surface of all this.
To simplify installation, I bulkhead mounted the antenna INSIDE the boat as an experiment, and it's been working reliably there ever since: saved me drilling a hole in the deck.