Navtex coverage

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icarusbop

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Hello:

When I purchased my boat it had a Navtex unit with a faulty display installed. She has been brought up from Portsmouth and now sits in Fleetwood marina.
I have repaired the display and it now looks to be working fine, but am receiving no messages. The unit has been left switched on for over a week, and the antennae is connected.
I was wondering if the Navtex system messages would be received at my marina in Fleetwood, according to my research the nearest station is in Portpatrick which as the bird flies in roughly 92NM, or if my antennea is faulty?
Can anyone advise if I should be able to receive Navtex messages at Fleetwood marina?

Thanks.
 
It is said that the density of vertical metal masts in the average marina interferes with Navtex signals (the only boat I've used Navtex on didn't live in a marina so I don't know first hand).

Also worth making sure your filters etc aren't excluding stuff you want.

Pete
 
The antenna units tend to be a bit dicey as do the connections. Which unit is it? Some of them there is a mode to display the spectrum being received. If it's not at full peak in the middle of the display then reception is iffy.

Are you set to the right frequencies? As mentioned make sure you have not got filters set.
 
icarusbop said:
Hello:

When I purchased my boat it had a Navtex unit with a faulty display installed. She has been brought up from Portsmouth and now sits in Fleetwood marina.
I have repaired the display and it now looks to be working fine, but am receiving no messages. The unit has been left switched on for over a week, and the antennae is connected.
I was wondering if the Navtex system messages would be received at my marina in Fleetwood, according to my research the nearest station is in Portpatrick which as the bird flies in roughly 92NM, or if my antennea is faulty?
Can anyone advise if I should be able to receive Navtex messages at Fleetwood marina?

Thanks.
Click to expand...

Call MCA and ask them if the service has been disrupted recently. Or call the local CG, though they do not always know

Last summer there were occasions when because of industrial action messages were not being broadcast. This lead me to strip the whole system down and be on the point of chucking it all away - when hey presto it all came back to life.

Also a small hint is to check that the settings of the system are not ignoring Portpatrick and just listening for other stations - ask me how I know.
 
Might depend on your set.

I have run a NASA and Furuno unit with the antennas a couple of feet apart under my sprayhood in a poor reception area. Both set to receive everything. The Furuno was displaying around 20 complete messages for every three or four (some partial) that the NASA set picked up.
Also, NAVTEX is an offshore system so inshore coverage often suffers from interference such as from masts, buildings or land path. The antenna location on your boat may also be a problem, get it as far away as possible from lumps of metal such as a stowed outboard or vertical wires.
 
As others have said, it depends what kit you're using; I briefly tried a NASA Navtex, had no joy at all even in a clear reception area so smartly marched it back to the chandlery; they didn't seem at all surprised and gave me an instant refund.

Incidentally, I love Portpatrick and the Crown Hotel's rooms and food, best ever steak or surf n turf, but I've only ever visited by road while working at the nearby aircraft test range so far; the harbour entrance looks a bit sporting but fine in good weather...
 
Thanks for the support:

The device is a Nasa Navtex Pro, it is currently set to receive all messages from all stations.
There are numerous antennae on my boat. This weekend if I get time I will try and trace out which antennae it is connected to and do some other checks.
For testing putposes, could I swap it with the antennae for my radio to see if that resolves the problem? This would help identifiy if it is the unit or the antennae/cable/location that may be at fault.
 
icarusbop said:
Thanks for the support:

The device is a Nasa Navtex Pro, it is currently set to receive all messages from all stations.
There are numerous antennae on my boat. This weekend if I get time I will try and trace out which antennae it is connected to and do some other checks.
For testing putposes, could I swap it with the antennae for my radio to see if that resolves the problem? This would help identifiy if it is the unit or the antennae/cable/location that may be at fault.
Click to expand...


When we had a NASA NAVTEX PRO we found it helped to earth the aerial screen.

Get to where the aerial comes through the deck. Bare the screen and connect DIRECT To a good solid eart such as a sacrificial anode.

Remember the BAVTEX is not intended for use in harbour. Reception there is a bonus. On the other hand, no night time reception from sky wave signals does suggest that you have a problem. Try my aerial earthing idea.
 
icarusbop said:
Thanks for the support:

The device is a Nasa Navtex Pro, it is currently set to receive all messages from all stations.
There are numerous antennae on my boat. This weekend if I get time I will try and trace out which antennae it is connected to and do some other checks.
For testing putposes, could I swap it with the antennae for my radio to see if that resolves the problem? This would help identifiy if it is the unit or the antennae/cable/location that may be at fault.
Click to expand...


When we had a NASA NAVTEX PRO we found it helped to earth the aerial screen.

Get to where the aerial comes through the deck. Bare the screen and connect DIRECT To a good solid earth such as a sacrificial anode.

Remember the BAVTEX is not intended for use in harbour. Reception there is a bonus. On the other hand, no night time reception from sky wave signals does suggest that you have a problem. Try my aerial earthing idea.
 
The range of Navtex is considerable, although no doubt affected by atmospherics and geography. In Greece we have received forecasts from The Netherlands, Iceland and Niton and a station in North Africa is particularly strong. As others have said it is common to not receive much in ports and marinas, whereas on open water all is well. My experience is that it is unusual to receive nothing at all in a week, which may indicate a fault somewhere. The antenna electrics can become salt encrusted as the white plastic case 'breathes'. I have washed mine in fresh water and restored it to working condition.
 
Not receiving info in harbour equates to ' set sail and see what you get ' !

I had no luck with a NASA Navtex on a mooring where reception of everything else is fine.

I think a laptop in range of a wifi gives much better information before one sets off, for example Chichester Harbour sailors can get onto CHIMET for a real time readout of conditions at the entrance, and also through the Solent.

I'd say that info before deciding to set off is the critical decision making point for coastal sailing.
 
Seajet said:
As others have said, it depends what kit you're using; I briefly tried a NASA Navtex, had no joy at all even in a clear reception area so smartly marched it back to the chandlery.
Click to expand...

I agree entirely. On a Furuno set I could receive Tunisia from the North Sea, but on a Nasa set could not get anything from Portpatrick despite being able to see the aerial above the town. I went into the harbour, walked up the hill, and asked the man in the BT shed who was typing it in to read the forecast to me. That last bit may be poetic license, but I did look in the window.
 
By no means am I suggesting that what you say is untrue but it certainly is not my experience. I have owned about half a dozen Nasa Navtex sets, starting with one of the very old LCD sets and progressing through to the Pro Plus. Other than problems with the antenna due to salt getting inside, all have been reliable. My Pro Plus in Greece regularly receives from Iceland and The Netherlands and never misses the Greek forecasts. My boat in Milford Haven has one of the old 'letter box' displays with the wire aerial. It receives perfectly with the antenna inside the wheelhouse.
 
Can I say, once again, that NAVTEX is intended for use by ground waves. The maximum intended range is no more than 400 miles and 200 miles is the normal limit. Transmitting power is deliberately limited to about 1 kW by day and 0.25 kW at night.

The information refers to the coverage area – ie generally no more than 200 miles from the fairway buoy.

Long distance reception is a nighttimes nuisance because it can overwrite the station that you want to receive. Valentia in Ireland can overwrite Toulon (both station E) and Cullercoats can overwrite Tarifa (both station G.) See http://weather.mailasail.com/Franks-Weather/Navtex-Reception-Problems-And-Cures for the reasons.
 
DaveS said:
I find that in my marina (Craobh) I cannot receive Portpatrick, but Malin Head is quite clear. As others suggest, start by not filtering out any stations.
Click to expand...


This is because of topgraphoc shielding. After pressure by the MCA MSI sub-group, the MCA negotiated with the Irish NAVTEX people. The result is that Malin Head duplicates much of Portpatrick on 518 and 490 kHz.

In that area you should select both stations by their identifier letter.
 
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