Best Navtex (PBO recent survey?)

[Oldhand]

Old and slow technology it may be but it can convey any information which can be put into text and that's quite a lot! As far as I'm concerned if gives me forecasts for where I am and for where I want to go and if I missed audio broadcasts then that is new and very usefull information. It also provides NM's which may be difficult to assimilate by just listening to CG radio broadcasts and would otherwise need an internet connection to find and read.

So I beg to differ, I think Navtex is great, all the information you should have is right there to read at any time.

 

[Oldhand]

Re: ICS reception...

I would suggest the ICS receiver is more sensitive than the Furuno one and thus could be more susceptible to interference. Do you get a "SIG" icon appearing next to either the 512 or 490 at the top of the screen on the Nav6? If alarms are enabled the "SIG" warning would also be accomapnied by an audio alert. The "SIG" message indicates interference on the frequency it appears next to.

I have a Nav6A which is connected to a masthead active whip. However, my Raymarine RN300 GPS when connected to Seatalk emits extrely strong EMI at 490kHz which, even using a masthead antenna, causes the "SIG" alarm to come up on 490kHz. Tha said, the decoding capability of the Nav6 is still good enough to get 490kHz Navtes messages with very few errors from Corsen, some 200nm away.

As an indication of the sensitivity of the ICS Nav6, it has decoded messages from stations as far away as the Med at night.

 

[Oldhand]

Re: Best choice is...

Many onboard electrical items, such as your engine alternator, fridge and electronic equipment such as GPS receivers, plotters etc. can emit radio frequency interference. This is usually more prevalent at the lower end ot the radio spectrum, where Navtex operates. If you have equipment which produces such "EMI" (electromagnetic interference), the closer a receiver antenna is to the source, the more likely the performance of the equipment connected to that antenna will be degraded by interference.

On a sailing yacht, the furthest away one can position an antenna from likely EMI generators is the masthead. A whip antenna is the lightest and least windage type so is commonly used at the top of the mast (think VHF antenna for example). An active whip is a receiving antenna which uses a pre-amplifier to boost the signals received before passing them on into the receiver. This is usually a good idea where there is a long cable run between the antenna and the receiver which will attenaute the signal.

 

[Oldhand]

Re: Best choice is...

The following 2 Greek Navtex stations on 518KHz should be within range of the Aegean Turkish coast. Whether the information they broadcast cover your sailing area is another matter:

Limnos[L] at 0150,0550,0950,1350,1750
Irakleio (Crete)[H] at 0110, 0510, 0910, 1310,1710,2110

There may be Turkish staions as well. The above information is from Admiraly Publication NP289 updates which I happen to have stored from downloads on my PC. However, my copy of NP289 is on the boat and thus I can't look up if Turkey has Navtex transmitter.

For details of relevant Admiralty Nautical Publications see:

http://www.admiraltyleisure.co.uk/prodservs/publications/np289_290.asp