AIS Transmitter / Transponder

[colbysmith]

Thought I'd start a new thread on this topic as more folks are considering adding AIS transmitters to their boat. I have had the Standard Horizon GX 2150 for two seasons now, and very happy with how it has received AIS signals, which I have repeated to my Garmin GPSMAP 840 and 541. But with the recent availability of a Chinese unit under $400 that transmits Class B, I decided it was time to add one to my boat. The unit in particular is the HP-33A, that Robert from Brazzo mentioned getting in his boat prior to beginning his Alaska Inland Passage cruise. I've also read several other forums that have favorable reviews of this unit. Right now it's available on Ebay for $379 with free shipping.

http://www.ebay.com/itm/252175420090?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

I don't want to add any more antennas to my boat, and with two VHF radios and their separate antennas, I also decided to get a splitter to hook the AIS unit up to the antenna on my "standby" radio. The splitter is a Vesper unit that you can find on Amazon for just under $240.

http://www.amazon.com/gp/product/B0087HHO52?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

So for under $620 I have a decent AIS Transmitter system. I will have to put one more antenna on my roof, a small GPS antenna that comes with the HP 33A, but I can find room for that.

I had been thinking about the AIS transponder for some time, and can think of a few times it would have been nice to had. (While running in fog or heavy rain squall, with large ships near by!) I see it as a nice compliment to the radar I already have. Not to mention that this unit will also be another GPS backup.

I plan on reporting back later after it's installed and again after some use of it in the spring and summer. Colby

[hardee]

Colby said:
.... (stuff clipped.) " I will have to put one more antenna on my roof, a small GPS antenna that comes with the HP 33A, but I can find room for that.

I had been thinking about the AIS transponder for some time, and can think of a few times it would have been nice to had. (While running in fog or heavy rain squall, with large ships near by!) I see it as a nice compliment to the radar I already have. Not to mention that this unit will also be another GPS backup."

Colby, Why do you need to put another antenna on your roof if you are using that splitter? If it is just a GPS puck, how about putting it on the shelf above the front window?

AND
How is it that this unit will act as another GPS backup?

I have been running an active AIS (Class B transponder) for 2 seasons now and consider it a valued asset. My (Vesper WatchMate) has it's own monitor screen with a very rudimentary "Coastal" outline so it gives me rough idea where I am among the surrounding islands or shore line. I would consider that as a rough GPS backup.

Good that you brought this subject back, as I think it is an important one, and for those of use who are not cruising around in circles with a pull toy tied on the tow ring, I think it is good to be aware of the possibilities for expanding horizons, and the safety implications.

Harvey
SleepyC

[thataway]

I am going to ask the same question I asked about the Brazzo installation (which we have no report back on from the original thread):

That is is this product FCC certified? Is it CE (European) certified? There is a reason that many of these Chinese products are cheap. They don't get the FCC certification.

If you can absolutely say, it is FCC certified--then good. I cannot find information that it is. One of my friends says it is not. If so, it would not be legal to use as a US boat in US waters.

I don't understand the not wanting another VHF antenna. The VHF frequency for the AIS is different than where the VHF radio is tuned to. The SWR, will probably be acceptable, but probably not optimal. Despite what the manufacture tells you, there is always some loss of signal when you put any fitting in a coax. The stronger your signal, the better chance of your being "seen" by other boats. (Yes, signal strength counts).

Why put the GPS antenna on the cabin top? Does it not work when under the cabin top? All of my GPS work very well in the cabin. If it does not work in the cabin, then I would question the receiver.

I read a number of threads about this unit. It works--there have been issues in hooking it up, and soft ware updates. You are working with a Chinese company, thru a dealer, probably outside of the US--who gives support?

My personal thought is that if and when I put on a AIS transceiver, I will use one of the companies which went thru the time and expense to get the unit FCC certified. (The issues with of loss of a license is greater for me, than someone who is not a ham. Is the FCC going to track you down, pull licenses, and fine you--unlikely.) If it is really FCC certified, then this does not apply.

[colbysmith]

Harvey, it is a full function display that can also store waypoints and tracks. I do not believe it has marine charts, but does appear to have compass rose type of tracking or map tracking (without streets or marine stuff.) It has it's own GPS receiver and can display the same location and SOG stuff, etc as my GPSMAP plotter. And of course the screen can also show the other AIS contacts. (Just google the unit, and you can see what the screens can show.)

Bob, I don't know if it's FCC certified, or not. I guess I trust that if they are selling it in the USA, they have received the permits to do so. But I will continue to look more into that.

As for the GPS antenna, I don't have that shelf over the window anymore, as I made it into a compartment to store charts and such! But I will have to look more into that once I receive the unit. I really don't have room for any more VHF antennas on the boat. I have two now. A 8' and 4' and I'm replacing the 4' with another 8'. I'm satisfied that a splitter won't reduce the effectiveness of the antenna for my use. From my little understanding of the frequencies, it does appear to be within the upper VHF frequencies. (Ch 88?) Again, as for VHF use on this antenna, it's primary use is back up and for short range calls in port. The AIS will be for relatively short range use as well. (Within several miles.). So I really don't understand your persistence about using a separate antenna for the AIS. Also, the splitter is amplified, so I understand that reverses the loss. If I only had one antenna and one VHF, that would be another story. I am purchasing the unit direct from the manufacturer, I believe. I understand the risk of doing business with a foreign company. Then again, sometimes even the domestic companies don't back their products up...

[hardee]

Colby,

I'll take a look at the screen. Obviously if you like it and it works for you, it's up to you.

As to the antenna farm concept. I understand that conundrum. I added another VHF to SleepyC last spring, ahhh and if you're counting that makes 3, and I struggled with adding another splitter and running 2 VHF's, both on splitters, or add a third antenna. The Vesper splitter is powered and that does eliminate the db loss of the older traditional versions.

One of the big issues is getting the antenna at a proper distance from the direction sensor for the AP and from the compass. I did add a third antenna, so now there is one 8ft FG Commrod, and 2 Shakespeare 4 ft, one of which is up on a 24 inch extension pole.

The third one is port side, at the aft boarder of the front windows. That put it 36 inches from the AP sensor and 48 from the KVH compass. The third antenna folds forward for travel, the other two fold aft. Each is secured for travel so the tips are not hitting the cabin top.

Harvey
SleepyC

[colbysmith]

Removed for repeat post

[colbysmith]

Harvey, I have both my antennas towards the front of the roof, and on each side of the "high top". So I barely have 3' between then, or real close to that. My Auto Pilot stuff is all down low, under my helm seat, so plenty of distance there. Both my VHF radios are mounted on the bottom of that top shelf over the windshield. (I just installed a door to the top of the shelf, to keep my charts and some other items.) the radios are above the helm area also. So I'm probably again just barely 3' with my starboard antenna, and the radios, but I have not experienced any problems. Of course that was my 4' SS whip, that I am replacing with another 8' antenna. Colby

[hardee]

HI Colby,

My positioning is basically the same as yours. One more VHF to port of yours, my radar is up on a 6" pedestal, and the new antenna is (as described) port side 2/3rds towards aft on the flat, outside of the handrails.

If you have auto pilot, there is a direction (position) sensor somewhere. Mine is supposed to be 28 inches (IIRC) from electrical wires or metal caches. I believe the radios are also supposed to about that distance from a compass.

I used the Shakespeare 4ft steel whip for that aft antenna, and it is low on the roof so it doesn't show from very far away.

Since I dock starbd side exclusively, boarding is from that side only. My 8ft antenna folds down to the rear, and impedes into the cockpit about 3 feet. With it on the port side it is not in the way at the dock. Yes, it is normally up but at launch and retrieve it is down, and there is usually some boarding activity going on then. I keep a foam pipe insulation piece over it with some yellow tape at the end for eye protection when it is down also.

Technically, the AIS is a slightly different frequency, (higher I think), so the AIS antenna is slightly shorter, but according to the tech support at Vesper and the EE at Rodgers, it is acceptable, (maybe not optimal), to share an antenna with marine VHF through the Vesper Splitter.

I have one GPS puck on the top of the brow, and 2 tht are under it on the shelf, in the enclosure behind where your door is.

Harvey
SleepyC

[Rain]

Where do you guys "hide" your anchor lights? Do you remove or lay them down except when required? I don't see them on either of your boats in the photos above.

[thataway]

Rain, I if you look at both photos, there is a black cap over the base for the anchor lights on the brow. Many of us take the anchor light down, unless we reed it.

As for "amplified" antennas, this is on the reception only. To amplify either the AIS or VHF radio frequencies, would require a whole other set of FCC tests, which without that amp would be illegal.

The Chinese have been shipping all sorts of non FCC or CE (European certification) into the USA and Europe. Note that you are buying from a dealer or the factory in China. So far I have not heard of anyone ticketed for a non type standard AIS,. FCC certification is what held up many of the main stream manufacturers selling their products. It is up to the user to be sure that it is certified.

It will be interesting to see what range you are seen at--and what range you see.

[colbysmith]

Rain, Bob is correct about the black caps and many not putting up the masthead light unless needed. However, and unfortunately not able to see in my photos, I have another "anchor" light that is on a 18" post behind my radar. I'll go see if I can find a photo showing that. Harvey, as for my VHF antennas, the taller port one, I can lay back, and that is where I usually keep it when trailering or locally. I'll lay it all the way down when trailering, but otherwise keep it up just high enuf that I don't hit my head on it when I crawl over the gunwale when the boat is on the trailer. And unless I plan on using the radio much, at least on the local lakes it stays in that position most the time. (Even when trailering as short distance.) However, out on Lake Michigan or if I plan on using the VHF much, I raise the antenna all the way up. I also have a nice full cover, and when I use that, I lay the antenna forward, as it is protected from the weight of the cover by the brow and bow rails. (I also recently started putting a long schedule 80 PVC pipe over it to stiffen it that much more in the middle between the brow and rail and that's mostly for when I'm putting the cover on, before it's tight and supported by the rails, brow and cover support posts!) The starboard 4' antenna is fine just laying down aft. Once I replace that with another 8', I will do the same with that one. Lay aft without the cover, lay forward with the cover.

Again, regarding signal loss in transmit of either the VHF or AIS, I'm not overly concerned. The Antenna I will be splitting between VHF, AIS and FM, is on my second "standby" VHF, that is primarily used for short distance calls. My AIS is primarily for traffic avoidance, and as long as I get several miles, it's served it's purpose. I will admit, the difference is noticeable when listening to different distance weather stations between the radio with the 8' antenna, radio with the 4' antenna or the handheld. I'm sure replacing that 4' with another 8' is going to improve that radio's reception and transmission, but splitting it will degrade it somewhat again. But I don't believe to an unacceptable level, or even back to where it currently is with the 4' whip.

Colby


Rain, if you look close, you can see my mastlight right behind the radar dome. It can also be laid aft for trailering or when my cover is on. Actually, I leave it down most the time, unless I need to use it. I installed this lamp as I wasn't sure that those behind me would see my "anchor" light with the radar dome in the way. I simply added a wire from the original post mount to the new one, so in essence, if I ever wanted to use the front mount, it still works.

[colbysmith]

Harvey, I forgot to mention that my Autopilot direction sensor is also under my helm seat. So well away from all the radios and antennas. Colby

[hardee]

[Rain]

I see it now.

[hardee]

I don't leave the anchor light up all the time because I'm not sure that the socket that the pole sets in is very water tight. Also, it is just shy of 12 tall, almost 2 feet taller than my radar, and I don't want it up when towing or just to go for the ride.

Harvey
SleepyC