a few questions about NAVTEX

[paulsmith]

1 Why is it that when I receive national 490kHz messages from Portpatrick and Niton does it say they are from Aberdeen although the message carries the correct ident letters i.e I for Niton and C for Portpatrick.

2 The transmission times from both stations according to the instructions and my almanac are all at 20 past the hour but all the messages I receive from Niton are on the hour or thereabouts and Portpatrick seem to be fairly random times.Why is this

3 What is the power consumption of a NASA CLIPPER NAVTEX it is recomended that the unit is left on so on arrival at the boat an up to date forcast is available but I would like to know what the battery drain is.
I'm sorry if this reads a bit like an exam paper but it was the only way I could think to put it.
answers gratefully received.
Regards Paul.

 

[ShipsWoofy]

3. PBO tested 3 navtex sets this month including power consumption when left on all week.

 

[sailorman]

my nasa navtex pro = 40 M/amps & its on 24/7

 

[Oldhand]

First in respect to your recption times are you using the time "stamp" on the messages to determine when they have been received or are you visually noting the time of receipt in real time? If you are using the former, are you providing your receiver with time input from your GPS or another source? If not the time "stamps" on the messages will be pretty meaningless apart from for assessing the time between messages. I haven't been monitoring reception times recently but have not noticed odd reception times in the past.

The content of Navtex messages is not all locally produced. I believe local Notices to Mariners are formulated for transmission by MRSC's but weather broadcast content has been centralised from a single source which appears to be Aberdeen.

The power consupmtion of your Clipper Navtex should be specified in literature which came with it, if not ask NASA. Certainly the "Target" navtex was quoted as drawing 40mA which in the majority of installations could be left on for a week.