Is my Navtex dead?

[fredrussell]

New to me boat has a Nasa Navtex fitted. The ariel is knocking around in the cabin - I mounted it temporarily on the pushpit and plugged in the coax cable to back of unit. When I switch it on the screen lights up green but no text is visible at all. Would one normally wait for the next broadcast before any text appears on screen or should I see something on screen straight away? If its a question of waiting for a broadcast, how often are they sent out? I'm up the Orwell on the east coast. Will Navtex work in this area or is it more designed for being out on the sea?

 

[macd]

If it's been off for a while you would expect no transmissions to appear on the screen. Usually old data is preserved, but the battery maintaining this usually flattens after extended non-use, in which case it's gone for good. (The internal battery should recharge if the set's left switched on.)

You should at least see a symbol in the top left corner indicating it's waiting for transmissions. Routine transmissions come several hours apart, so you wouldn't expect anything instantly unless there are safety messages buzzing about: pilot books/almanacs will give you the timings for your area. You may need to tell the set to listen to your local stations. The owner's handbook will tell you how, and the codes for different stations.

It may be worth fiddling with the backlight button: readability with some NASA sets is on a bit of a knife-edge.

 

[vyv_cox]

I suggest you program initially for all stations, all types of transmission. Some sort of message, usually nav warnings, will be received almost any time of day within a minute or two. There are many powerful transmitters around, we regularly receive Icelandic and Netherlands ones in Greece.

If the set continues to give you nothing I would open up the antenna. It tends to accumulate salt that shorts out the PCB. Washing it in fresh water has fixed mine several times.

 

[[3889]]

When I leave my Navtex off for several weeks it takes two or three days of power to begin displaying so I think the unit will revive given time but the internal battery is shot and this problem is unlikely to go away.
Have you tried holding down all 4 buttons for a factory reset?

 

[skip50]

NASA antenna are not known for being water/weatherproof. After a couple of replacements I mounted mine down below, actually as high as I could get it in the oilskin locker, problem solved. No noticeable deterioration of reception. Of course, this is on a GRP boat.

I agree with the above comments re batteries etc.

 

[PeterBoater]

Apologies for the slight thread drift but people having problems with the ICS Navtex might like to know that the fin antenna with built in receiver PCB that is very prone to moisture (I've had two fail) can now be replaced by a kit with a passive rod antenna that fits straight onto the original screw mounting and a separate receiver that is mounted in a dry area inside the boat. For some reason the cable for the new antenna comes out of a hole in the side of the antenna and should be rerouted out of the bottom of the antenna through the original mounting; the hole in the side can then be sealed. Assuming that the power supply is working, the display should show the setup pages even if no Navtex messages have been received. If it is receiving OK but waiting for a message it should show 490 and 518 at the top of the display, with no ERR next to them.

 

[NormanS]

I recall that some years ago, I had a similar problem with mine, showing a blank screen. It turned out that the "Brightness" control had been meddled with. I don't have the instructions here, but if you have, check for brightness.

 

[JimC]

I recall that some years ago, I had a similar problem with mine, showing a blank screen. It turned out that the "Brightness" control had been meddled with. I don't have the instructions here, but if you have, check for brightness.

Same here, I was on the point of sending mine back to NASA for a new screen when I noticed the contrast had been turned right down.

All the NASA instruction manuals can be downloaded from here:http://www.nasamarine.com/manuals/

This excerpt may be relevanr to the OP:

The message memory of the Clipper Navtex is powered by an
internal rechargeable battery. When the unit is first installed (or has
not been used for some time) this battery may be discharged
resulting in either a complete absence of display or the contents of
the message memory degraded into a random pattern.
Connecting the receiver to its 12 volt power supply will begin to
recharge the battery (complete charge time is 40 hours). Normal
operation will occur after about 10 seconds. It is advisable at this
stage to reset the unit by simultaneously pressing all four keys.
This re-boots the software and returns with the Welcome screen.
From here the Main menu is accessible, the contrast can be
adjusted, or the message memory cleared. To make a choice
follow the instructions on the screen.

 

[NormanS]

Yes, Contrast rather than Brightness.

 

[westhinder]

Has anyone ever replaced the internal battery? My set does work, but does not remember the settings when the lectrcity is switched off. When I return to the boat all settings have changed randomly. I usually don't bother anymore as most of the information can be found more extensively on the internet.
But for the longer trips offshore navtex still has its use, so I'm interested in getting it back to normal.

 

[fredrussell]

Thanks everyone, loads of useful advice there.

I'll start with the contrast control, leave the power on for longer to try and charge the internal battery and I'll download a manual and see if it can shed some light on things.