SailNet Community

SailNet Community (http://www.sailnet.com/forums/)
-   Electronics (http://www.sailnet.com/forums/electronics/)
-   -   AIS Receiver installation (http://www.sailnet.com/forums/electronics/145698-ais-receiver-installation.html)

Yofy 06-07-2014 06:41 AM

AIS Receiver installation
 
I have just bought a new AIS Receiver - MXA-5000 and am trying to hook it up to my PC. MY PC uses C-map.

I installed everything according to the instructions that came with the instrument. When I connect the AIS receiver to my computer and my VHF antenna, the AIS power light comes on but I don't receive any data on C- map. (nothing comes up on the screen).

What could be the problem?
Do I need to install a program to interface between the AIS receiver and C-map?

Manny

SVAuspicious 06-07-2014 09:32 AM

Re: AIS Receiver installation
 
How are you getting data to your PC? Do you have a serial port or a USB converter? Do you have C-Map configured to get data from the correct port? Do you have the speed on the PC serial port set correctly? Does C-Map have a configuration item to tell it to look for AIS?

Yofy 06-08-2014 03:45 PM

Re: AIS Receiver installation
 
Quote:

How are you getting data to your PC? Do you have a serial port or a USB converter?
I have a serial to USB converter

Quote:

Do you have C-Map configured to get data from the correct port?
Yes

Quote:

Do you have the speed on the PC serial port
set correctly?

Don't know. I'll check that.

Quote:

Does C-Map have a configuration item to tell it to look for AIS?
No not for AIS. IT has for other devices but not AIS.

I also tried connecting the AIS to "Open CPN" which does have a designated AIS connection and didn't receive any data there either....

Manny

SVAuspicious 06-08-2014 08:02 PM

Re: AIS Receiver installation
 
Some serial-to-USB converters work better than others. There can be driver issues.

Your Icom AIS receiver, like most, outputs data at 38400 bps.

Are you sure that C-Map will show AIS? OpenCPN certainly will.

Tim R. 06-08-2014 08:23 PM

Quote:

Originally Posted by Yofy (Post 1911386)
I have a serial to USB converter Yes set correctly? Don't know. I'll check that. No not for AIS. IT has for other devices but not AIS. I also tried connecting the AIS to "Open CPN" which does have a designated AIS connection and didn't receive any data there either.... Manny

Speed should be 38,400. Could it also be that there simply are no AIS targets in range? How are you connecting to a VHF antenna? Are you using a splitter or a dedicated antenna? Some splitters work better than others.

SVAuspicious 06-09-2014 07:18 AM

Re: AIS Receiver installation
 
Quote:

Originally Posted by Tim R. (Post 1911994)
Some splitters work better than others.

In-band splitters are fundamentally bad and should be avoided.

transmitterdan 06-09-2014 07:29 AM

Re: AIS Receiver installation
 
Quote:

Originally Posted by SVAuspicious (Post 1912770)
In-band splitters are fundamentally bad and should be avoided.


These blanket statements are not helpful to novices. There isn't anything "bad" about splitters. Some are better than others.

The points against splitters are twofold. First there can be attenuation of the transmitted or received signals. This is usually specified in the technical data of the splitter. It is possible to build a splitter with very low attenuation. Second, is the time sharing of transmission as the VHF and AIS cannot transmit at the same time. This second issue is not a big problem for most cruising boats.

There are also points in favor of splitters. Ease and speed of installation are a good thing. Usually the mast head antenna can be used which due to height can more than make up for any splitter loss.

So maybe we should just list the pros and cons and let the reader decide what is "good" or "bad" for themselves.

SVAuspicious 06-10-2014 10:12 AM

Re: AIS Receiver installation
 
Quote:

Originally Posted by transmitterdan (Post 1912802)
Quote:

Originally Posted by SVAuspicious (Post 1912770)
In-band splitters are fundamentally bad and should be avoided.

These blanket statements are not helpful to novices. There isn't anything "bad" about splitters. Some are better than others.

A blanket statement in response to a blanket statement? *grin*

There are lots of things bad about splitters. I've held forth on this subject before and will again.

Quote:

Originally Posted by transmitterdan (Post 1912802)
The points against splitters are twofold. First there can be attenuation of the transmitted or received signals. This is usually specified in the technical data of the splitter. It is possible to build a splitter with very low attenuation. Second, is the time sharing of transmission as the VHF and AIS cannot transmit at the same time. This second issue is not a big problem for most cruising boats.

Not "can be attenuation" - WILL be attenuation.

You can certainly find splitters with very low noise pre-amps before and after the switching circuitry with additional amplification on each leg. Those are pricey units.

Commonly available splitters attenuation is 2.5 - 3.0 dB. Add .20 - .25 dB each for the connectors on each side and it adds up. You already knock down your signal 4.5 dB / 100 ft (at least - not all 8X is equal and 58 is worse) in the coax. Why give up more that you don't have to?

Let's ignore coax loss since that is common to both alternatives. Add a splitter and both the VHF and AIS will take a hit of 3.0 - 3.5 dB, a reduction in received signal strength AND transmitted of half. Over clear water line-of-sight is more important than power but if you are in a winding channel or dealing with propagation over hills or through trees such as around a point or past industrial buildings in a port you'll want all the power you can get to take advantage of refraction and reflection.

Quote:

Originally Posted by transmitterdan (Post 1912802)
There are also points in favor of splitters. Ease and speed of installation are a good thing. Usually the mast head antenna can be used which due to height can more than make up for any splitter loss.

From a practical point of view the value of height is over-rated, particularly with regard to large commercial traffic. I'll post the numbers when I figure out a way to convert the table I have in a useful form.

Quote:

Originally Posted by transmitterdan (Post 1912802)
So maybe we should just list the pros and cons and let the reader decide what is "good" or "bad" for themselves.

I stand by my statement that in-band splitters are fundamentally a bad idea. That is different from an FM/TV splitter (a notch/bandpass filter since FM radio is between TV channels 6 and 7) or a VHF/FM splitter (VHF 150 - 165 including weather and FM 88 - 108 MHz). In-band is entirely different. After all the AIS channels ARE VHF channels (87B and 88B).

Adding a second independent antenna on the pushpit, a radar pole, arch, or spreader is not that hard, particularly if you DIY. People--including novices--should know that there is a greater detriment to the splitter approach than the manufacturers promulgate.

Tim R. 06-10-2014 11:30 AM

Would love to see some side by side real time comparisons between splitter and non splitter AIS reception and VHF radio performance.

My AIS transceiver w/splitter has picked up signals as far as 34nm away.

Yofy 06-10-2014 03:42 PM

Re: AIS Receiver installation
 
Quote:

Could it also be that there simply are no AIS targets in range?
No, we are always in range of ships here.
Quote:

How are you connecting to a VHF antenna?
with a proper VHF plug

Quote:

Are you using a splitter or a dedicated antenna?
Dedicated antenna.

The installation is fine. I think that I may be missing a driver although when I bought the AIS receiver they assured me that I didn't need any other program or driver. Anybody know of a good site where I can download a driver for AIS to C map?


All times are GMT -4. The time now is 08:25 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012