Nasa AIS instructions

30boat

30boat

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I've installed a Nasa AIS.The instructions I downloaded are not great so I have doubts.
I still haven't received any data but there is very little navigation in these waters.Still at max range I should be getting something.
What channel should I use ,A , B or both.
What should the signal strength be?I'm getting a bar of about 35% of the total lentgh but it peaks on and off.I've tried two aerials through a splitter and it's the same.I can't connect the aerial directly to the set because ,for some reason,the terminals are not the same.
What's the stored GPS position for?
Ok that's about it for now.
 
My suggestion would be to buy a new terminal that is compatible with the connection on the AIS and connect the aerial directly to it.
At least then you have the best chance of a good signal.
Then take it from there and reassess.

I would set it to receive both A and B so you have the best chance to see all vessels.
Sorry unable to help with stored GPS position.
 
The instructions do specifically say you should not share aerials, so using a splitter is not helping you. So fitting the correct plug on the aerial lead and plugging it in direct would be good.
I have always found that NASA are extremely helpful on the phone.
 
Cantata said:
The instructions do specifically say you should not share aerials, so using a splitter is not helping you. So fitting the correct plug on the aerial lead and plugging it in direct would be good.
I have always found that NASA are extremely helpful on the phone.
Click to expand...
This is an AIS specific splitter with a lead that says "AIS" so I'd think it should work.I've sent them an email anyway.
 
If you have an android or apple phone, you could download the free app from fleetmon which will show live AIS information - at least for commercial traffic. If that's showing traffic in your vicinity and your AIS unit isn't then you will at least know something is wrong.

There are probably other apps or online resources showing live AIS information - but that's the only one I can remember off the top of my head.
 
30boat..

I have not had the NASA AIS Radar for a while now but seem to remember that the Threshold setup was rather important but also rather lacking in clarity in the manual.

The manual talks about setting the THRESHOLD bar to the midpoint of the RX SIGNAL bar.. Did you follow that instruction to the letter?

With this THRESHOLD set incorrectly, nothing will appear.
 
scotts_mist said:
If you have an android or apple phone, you could download the free app from fleetmon which will show live AIS information - at least for commercial traffic. If that's showing traffic in your vicinity and your AIS unit isn't then you will at least know something is wrong.

There are probably other apps or online resources showing live AIS information - but that's the only one I can remember off the top of my head.
Click to expand...
I don't have mobile internet on my tablet but I've just checked (good idea by the way)on my home computer and the nearest ships are at least 30 miles away if not more.
 
I have never got a great range from mine but it works well enough at sea where I only require 4 miles. If you are in a marina or up a river you may well get very little.
You should set the threshold above the minimum recieved signal, you may want to fiddle with this setting. The bar jumps across as it gets a shot of data, this is normal.
I think the only use of the stored position is to allow you to use the thing without the GPS input alarm driving you crackers.

The NASA Radar don't look that hot in harbour, at sea it is fine.
 
scotts_mist said:
If you have an android or apple phone, you could download the free app from fleetmon which will show live AIS information - at least for commercial traffic. If that's showing traffic in your vicinity and your AIS unit isn't then you will at least know something is wrong.

There are probably other apps or online resources showing live AIS information - but that's the only one I can remember off the top of my head.
Click to expand...

Such as http://www.marinetraffic.com/ais/ you should be able to see whats near you.
 
One of the bestest bits of kit in the world. Splitter is fine so long as all connections are good. Threshold should be set to just under the signal strength.

30boat said:
This is an AIS specific splitter with a lead that says "AIS" so I'd think it should work.I've sent them an email anyway.
Click to expand...
 
For your connection from a standard VHF antenna to the NASA AIS you should buy a BNC plug to UHF socket adaptor. You can get one from www.cpc.co.uk and it is listed as Order code. CN11949. The part costs £2.95. As stated above, do not share the antenna with another receiver, but give it an antenna of its own. With this adaptor, the antenna will not be modified and so it can be connected to another receiver if necessary, when not in use by the AIS.

There will probably not be very many class B transmissions in your area (private pleasure craft), so you might best try it out on Class A. Mine can receive from ships about 8 miles away.

The AIS needs to be used in conjunction with a GPS so that it can display the position of the ships in relation to your own position.

If you have the NASA AIS "RADAR" unit the display positions you at the centre of the screen using a NMEA input to the unit from your GPS. If on the other hand, you are using the NASA AIS engine and displaying the results on a chart plotter, the plotter will have its own built in GPS. If you are using the NASA AIS engine with a laptop, the instructions say that you should feed the GPS NMEA signal into the AIS engine which will pass the GPS info on to the laptop.
 
Last edited:
CPD said:
One of the bestest bits of kit in the world. Splitter is fine so long as all connections are good. Threshold should be set to just under the signal strength.
Click to expand...

I'll second CPD's quote. I utilised my VHF antenna through a splitter for Nasa AIS and received a good signal with shipping data. So good in fact, that when I first fitted it... my boat was ashore in a yard up the Penryn river and I could see all the shipping in Falmouth Bay nearly 3 miles away. And that's despite land, housing, and the docks complex being between my position and the Bay.
 
saxonpirate said:
I'll second CPD's quote. I utilised my VHF antenna through a splitter for Nasa AIS and received a good signal with shipping data. So good in fact, that when I first fitted it... my boat was ashore in a yard up the Penryn river and I could see all the shipping in Falmouth Bay nearly 3 miles away. And that's despite land, housing, and the docks complex being between my position and the Bay.
Click to expand...

Mid Atlantic I was getting ships at 30 miles+ with a pushpit mounted aerial.
 
30boat said:
I've installed a Nasa AIS.The instructions I downloaded are not great so I have doubts.
I still haven't received any data but there is very little navigation in these waters.Still at max range I should be getting something.
What channel should I use ,A , B or both.
What should the signal strength be?I'm getting a bar of about 35% of the total lentgh but it peaks on and off.I've tried two aerials through a splitter and it's the same.I can't connect the aerial directly to the set because ,for some reason,the terminals are not the same.
What's the stored GPS position for?
Ok that's about it for now.
Click to expand...

I had trouble with the threshold setting (instructions are not great). The bar hovers about 1/3 of the way across (background noise) and every now and then spikes all the way across (this is a signal coming in). Threshold should be set just above the background noise.
 
aslabend said:
I had trouble with the threshold setting (instructions are not great). The bar hovers about 1/3 of the way across (background noise) and every now and then spikes all the way across (this is a signal coming in). Threshold should be set just above the background noise.
Click to expand...
That's what I'm getting.I thought the signal was too low but apparently it's normal.that's good to know.I'll set the treshold tomorrow.The instructions are very poor indeed.
 
I contacted Nasa by email yesterday and this morning I had a reply.Great service. Set the threshold two clicks above the signal bar and suddenly I'm getting loads of targets.I'm a happy bunny.That was with the splitter which obviously works .
 
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