Cheap AIS transponder?

[BelleSerene]

The UK supplier for the ONWA KS-200A has quoted £420 Inc VAT + P&P.
http://www.mantsbrite.com/Onwa-KS-200A-Class-B-AIS-Transponder.aspx

The USA Amazon price is likely to be around £280 after adding shipping, VAT and a collection fee.
https://www.amazon.com/gp/product/B07796FCR7/ref=ask_ql_qh_dp_hza?tag=skim0x1773-20

Plus the rest, for an antenna installation or an antenna splitter so you can use your existing VHF whip for the AIS.

Hey, does anyone know what it matters in practice if this is just a single-channel box rather than dual-channel? It doesn’t claim to be dual channel, so it presumably won’t be.

Along similar lines, I was just impressed to find this combo available via eBay - www.ebay.co.uk%2Fulk%2Fitm%2F282364124240 - for just £165. AIS (receiver only, but a dual-channel one) plus antenna splitter so you can use your existing masthead antenna, plus it transmits on WiFi so you can use iPad apps etc - and it even multiplexes your 4800 baud NMEA data into the stream so you can read your instruments on iPad/ smartphone.

 

[TSB240]

It doesn’t claim to be dual channel, so it presumably won’t be.

From the horses mouth:

http://www.mantsbrite.com/Onwa-KS-200A-Class-B-AIS-Transponder.aspx[h=1]Onwa KS-200A Class B AIS Transponder[/h]Onwa KS-200A Class B AIS transponder enables you to broadcast your data to other AIS equipped vessels and receive their data.

• Black Box Class B AIS Transponder
• Transmits & Receives AIS Data
• Includes External GPS Antenna
• Receives both Class A & Class B AIS Messages
• 12 or 24 Volt DC Operation

Onwa KS-200A Class B AIS transponder allows real time information exchange between AIS equipped vessels by transmitting your vessels details such as Name, Position, MMSI Number, Speed & Course.
KS-200A also receives Class A & Class B AIS data, which can then be displayed on an AIS compatible Radar, Chartplotter or PC. Safety is greatly improved in weather, poor vision and congested waterways when sending and receiving AIS data.

 

[Yngmar]

Onwa is a Hong Kong based company. They design and manufacture their own kit, and have a pretty exciting and rapidly growing product line-up. I've had a brief glance at their radar set for when our ancient Raytheon finally croaks and mostly liked what I've seen.

Their chartplotters are Linux based (MIPS or ARM - I forgot) and look like they might become the holy grail device for us nerdy boaters - a waterproof computer with a sunlight readable screen and some buttons that we can run our own software (e.g. OpenCPN) on. Would probably take some hacking to do, but the basis is already there.

They also seem to have a deal with Jeppesen for free C-Map charts (with their plotters only and in their own format - K-charts).

For now it looks like Onwa is aiming to break up the existing cartel of laughably overpriced marine electronics. I hope they succeed!

 

[BelleSerene]

From the horses mouth:

http://www.mantsbrite.com/Onwa-KS-200A-Class-B-AIS-Transponder.aspxOnwa KS-200A Class B AIS Transponder

Onwa KS-200A Class B AIS transponder enables you to broadcast your data to other AIS equipped vessels and receive their data.

• Black Box Class B AIS Transponder
• Transmits & Receives AIS Data
• Includes External GPS Antenna
• Receives both Class A & Class B AIS Messages
• 12 or 24 Volt DC Operation

Onwa KS-200A Class B AIS transponder allows real time information exchange between AIS equipped vessels by transmitting your vessels details such as Name, Position, MMSI Number, Speed & Course.
KS-200A also receives Class A & Class B AIS data, which can then be displayed on an AIS compatible Radar, Chartplotter or PC. Safety is greatly improved in weather, poor vision and congested waterways when sending and receiving AIS data.

Yes, that's not saying it's a dual-channel device; it's just saying it receives and shows you both Class A and Class B AIS messages that it receives.

Single/ dual channel refers to whether it can receive the data transmitted on just one or both of the AIS radio channels. The transmitters on the boats around you switch periodically between one channel and the other, so eventually a single-channel box will pick them up anyway. But a dual-channel AIS receiver shows you new vessels sooner, and you see their full information more quickly, particularly when there are lots of transmitting vessels around.

 

[halb]

I'll second that, got one of their transponders (Matustic) with a screen, $300 delivered and very good it is too

 

[[163233]]

Yes, that's not saying it's a dual-channel device...

The spec is available here:-
http://onwamarine.com/ks-200a/

The manual is here:-
https://www.dropbox.com/sh/2nv0igkabk1cdj4/AAAQe2yEt5zbVhUl6rEOx7kga/KS-200_OME-160606.pdf?dl=0

Says it's dual channel, apparently with one channel also receiving DSC unless I've misunderstood?

Interesting piece of kit and at a sensible price for something like this, but I'd like a UK distributor in case of problems.
Their Hong Kong address isn't reassuring if you look it up on street view..

 

[rogerthebodger]

The spec is available here:-
http://onwamarine.com/ks-200a/

The manual is here:-
https://www.dropbox.com/sh/2nv0igkabk1cdj4/AAAQe2yEt5zbVhUl6rEOx7kga/KS-200_OME-160606.pdf?dl=0

Says it's dual channel, apparently with one channel also receiving DSC unless I've misunderstood?

Interesting piece of kit and at a sensible price for something like this, but I'd like a UK distributor in case of problems.
Their Hong Kong address isn't reassuring if you look it up on street view..

There is a list of dealers on their contact page. The link in post #24 is their UK dealer.

 

[BrianH]

Hey, does anyone know what it matters in practice if this is just a single-channel box rather than dual-channel? It doesn’t claim to be dual channel, so it presumably won’t be.

From the brochure I interpret two simultaneous duplex receivers:

VHF Transceiver

Transmitter x1
Receiver X2 (one time shared between AIS/DSC)​

Surely no one peddles a non-synchronous, alternating frequency, single AIS receiver these days do they? Oh, I forgot, NASA still does.

 

[dk]

From the brochure I interpret two simultaneous duplex receivers:

VHF Transceiver

Transmitter x1
Receiver X2 (one time shared between AIS/DSC)​

Surely no one peddles a non-synchronous, alternating frequency, single AIS receiver these days do they? Oh, I forgot, NASA still does.

In defence of NASA I believe its AIS Engine 3 is dual channel.

 

[Gwylan]

Dumbest question of the day.

We have a GPS aerial as well as an AIS aerial sitting on the stern. On a lucid day I fed the GPS to a splitter box using Wago connectors. This then links the VHF radio and other peripherals.

The AIS receiver had a dedicated lead that goes from the aerial to the Plotter which is installed at the helm. Can I use a T piece to take a feed from the AIS aerial to this unit?

The unit will not be too accessible, other than to switch it off when we want to go stealth mode - or not be tedious by leaving it on whilst sitting at the pontoon.


I said it was a dumb question.

 

[RichardS]

Dumbest question of the day.

We have a GPS aerial as well as an AIS aerial sitting on the stern. On a lucid day I fed the GPS to a splitter box using Wago connectors. This then links the VHF radio and other peripherals.

The AIS receiver had a dedicated lead that goes from the aerial to the Plotter which is installed at the helm. Can I use a T piece to take a feed from the AIS aerial to this unit?

The unit will not be too accessible, other than to switch it off when we want to go stealth mode - or not be tedious by leaving it on whilst sitting at the pontoon.

I said it was a dumb question.

That's certainly confused me.

If the splitter is a VHF radio frequency splitter how can you link that to a GPS which does not use VHF frequencies? Or are we talking about NMEA data rather than VHF? The GPS unit would have to be a receiver rather than an aerial and the "splitter" would presumably be a multiplexer?

Richard

 

[superheat6k]

Onwa is a Hong Kong based company. They design and manufacture their own kit, and have a pretty exciting and rapidly growing product line-up. I've had a brief glance at their radar set for when our ancient Raytheon finally croaks and mostly liked what I've seen.

Their chartplotters are Linux based (MIPS or ARM - I forgot) and look like they might become the holy grail device for us nerdy boaters - a waterproof computer with a sunlight readable screen and some buttons that we can run our own software (e.g. OpenCPN) on. Would probably take some hacking to do, but the basis is already there.

They also seem to have a deal with Jeppesen for free C-Map charts (with their plotters only and in their own format - K-charts).

For now it looks like Onwa is aiming to break up the existing cartel of laughably overpriced marine electronics. I hope they succeed!

Be wary of the K Chart - about as much use for navigation as an AA roadmap, at least the installed K Chart base map on the Matsutec HP series is certainly best described as very basic. Once the C Map card is loaded the resolution is excellent.

 

[BrianH]

In defence of NASA I believe its AIS Engine 3 is dual channel.

All AIS receivers are dual channel, not all are dual receivers. On cost grounds many early manufacturers used a single receiver that switched between the two channel frequencies.

From the official NASA Engine 3 web site:

Ais Engine 3
[ ... ]
The unit can receive ships on either the A or B AIS channels. In default setting it alternates between the two channels.
​

NASA AIS receivers have always been a single receiver with a front-end RF switch to alternate between the two frequencies. Incredible really when for only a little more cost the market is flooded with genuine parallel, synchronous-channel, dual receivers.

Does it matter? Yes, I think it does. I installed a single receiver unit in 2007 (not NASA) and noted immediately how long the static data took to be added to the target list, sometimes well over 15 minutes.

Ships' AIS data is transmitted in two packets split into static and dynamic data sentences with the important dynamic data sentence repeated every few seconds, depending on the vessel speed. The static data sentence is sent less frequently.

However, one component of the static data sentence is the ship's name, which I like to see on the screen as I found it very useful once to call on channel 16 when a 33 knot hydrofoil ferry was heading straight for me.

The reason for the slow update, of course, is that the static data sentence is sent only every 6 minutes and on only one channel at a time, the originating vessel alternating channels every transmission, irrespective of vessel speed or class (A or B). With only one channel of the receiving vessel being monitored at any single, discrete time, that sentence can be missed - even more than once if out of synchronisation with the transmitter - at multiples of the 6 minute frequency.

There is no excuse these days to buy a single receiver AIS 'engine' when prices are so reasonable. I exchanged my early, primitive receiver for an inexpensive 'transponder' with genuine duplex parallel receivers long ago and immediately noted the improvement in static data updating.


.

 

[mogmog2]

You really think they are lying? Is that based on any evidence or just a guess?

It's not beyond the realms of possibility:
The global marketplace is full of it:
https://www.dhgate.com/product/luxu...ttice/406508706.html#s1-0-1b;searl|0276437056
http://www.ybw.com/vhf-marine-radio...en-the-ce-mark-and-the-china-export-mark-4607
etc etc.

 

[doug748]

The ald NASA radar is a delight.

It's cheap, it works, it's simple to set up, it's available, it's intuitive in use and supported in the UK.

However it has little in common with the product the OP is considering, which looks grand in it's own right

 

[TSB240]

Yes, that's not saying it's a dual-channel device; it's just saying it receives and shows you both Class A and Class B AIS messages that it receives.

Single/ dual channel refers to whether it can receive the data transmitted on just one or both of the AIS radio channels. The transmitters on the boats around you switch periodically between one channel and the other, so eventually a single-channel box will pick them up anyway. But a dual-channel AIS receiver shows you new vessels sooner, and you see their full information more quickly, particularly when there are lots of transmitting vessels around.

I thought the days of dual band switching receivers were well and truly over.....

This unit receives from 156.025 to 162.025 MHz which covers both bands for AIS transmissions namely 87B (161.975 MHz)and 88B( 162.025 MHz).It needs to do this as it could never operate as a transponder without knowing if the frequencies were clear to transmit its class B transponder signal.....

 

[Yngmar]

Be wary of the K Chart - about as much use for navigation as an AA roadmap, at least the installed K Chart base map on the Matsutec HP series is certainly best described as very basic. Once the C Map card is loaded the resolution is excellent.

That's a base map you're talking about, it's only purpose is to show you where you are in the world in a very zoomed out view. The full K-Chart (several hundred MB download for Europe) is C-Map. Example: http://avesmarine.com/K-charts/

 

[superheat6k]

That's a base map you're talking about, it's only purpose is to show you where you are in the world in a very zoomed out view. The full K-Chart (several hundred MB download for Europe) is C-Map. Example: http://avesmarine.com/K-charts/

I am not disagreeing with you here, just buyers should be aware the makers supply the Matsutec plotters with what they describe as K charts installed. These have no defined detail at all. Mine required a CMAP for which I bought the Southern UK card for ~ £110. This does need to be borne in mind when comparing with something like a Garmin supplied preloaded with proper charts included.

I do wonder why none of the majors have come up with a combined Chart plotter / AIS transceiver.

 

[mogmog2]

In defence of NASA I believe its AIS Engine 3 is dual channel.

This is what NASA say for it "The unit can receive ships on either the A or B AIS channels. In default setting it alternates between the two channels." I'm new to this but I'm not sure that's dual channel?
I'll defend NASA too as they service an important slot in the market and help keep boating affordable.
FWIW, they offer an upgrade from previous versions to 3 for £12, which I think is laudable-so much tech stuff has to be binned.
http://www.nasamarine.com/product/ais-engine-3/

 

[BrianH]

This is what NASA say for it "The unit can receive ships on either the A or B AIS channels. In default setting it alternates between the two channels." I'm new to this but I'm not sure that's dual channel?
I'll defend NASA too as they service an important slot in the market and help keep boating affordable.
FWIW, they offer an upgrade from previous versions to 3 for £12, which I think is laudable-so much tech stuff has to be binned.
http://www.nasamarine.com/product/ais-engine-3/

You should read the thread properly, especially post #33.