New combination VHF radio, AIS reciever/Hailer

thataway · Posted: Sat Mar 20, 2010 5:17 pm Post subject:

We used the recorder mostly for weather and similar communications. Also used it fairly often with the Ham radio communications if there was a lot of information and we didn't have time to write it down accurately. The digital units come on almost instantly--so if you have handy, you can turn it on fast enough. A "MayDay" should come first, and other information, before the Lat and Long--but you never know.

As for two radios and two antennas. Generally it is not a good idea. You run the risk of damaging the receiver section of the ration which is not transmitting. There are both electronic and manual switches which do allow the use of two radios on one antenna, and I have used both types--but mostly on Ham gear or HF gear--not VHF.

The other point--is that one of the reasons to have two radios, is so that you can receive a transmission from another station, when you are transmitting. I keep going back to the same example--but it works. If there is an area which requires a "securitie" message, on two frequencies, then you might be transmitting on 16, when another boat is transmitting on 12 or 13, and both miss each others message. This is more likely to happen on narrow areas of the ICW than in the PNW--but I can think of reasons and areas up there where it would be as valid as the "Rock Pile" in the Carolinas.

Grumpy · Posted: Sat Mar 20, 2010 7:00 pm Post subject:

I have had bad experience with using an electronic "splitter" to run two radio's on one antenna. It definitely works but in order to do so it disconnects the radio which is not transmitting which defeats at least one of the purposes for having two radios. ie. for the example that Bob mentioned.

If using two radios and two antennae they need separation or you will get breakthrough on the non transmitting radio caused by overloading with the signal from the one you are transmitting with.
In that respect, not all radio's are created equal even though you might think it from reading the published specs. At 6ft spacing I can still get get some occasional breakthrough on the cheaper of my two radios (both from the same manufacturer, just different models and the "cheap" one was bought discounted at a sale. Pretty clear why)

There is one feature of the new Matrix with AIS that I like and that is the ability to press one button and send directly to the target of your choice on AIS. I know you can hail them by name but using the DSC function seems much more logical as their radio will ring like a telephone until they answer it.
Without that ability you would need to input, via the menu, the target MMSI # which is a whole bunch of fun in bad or close conditions which is exactly when you will probably want to to it.
Since I already have AIS, the cheaper version would suit me fine and I also have a multiplexer to get over the Raymarine E-120's lack of "ears" so I think I will replace my "cheapo" radio with one of these.

Oh, if you do fit two radio's be careful about putting your MMSI in both of them otherwise they will both sound alarms, bells and whistles every time there is a general broadcast, Pan Pan or mayday and you will immediately think that you have engine temperature alarms or whatever. Very confusing.

And don't think there is a common procedure for switching OFF the alarms even on radios from the same company. That would be too easy Rolling Eyes

That's my 2c worth.(and you got it for free)

Merv

SGIDave · Posted: Mon Mar 22, 2010 7:10 pm Post subject:

hardee

Tortuga · Posted: Tue Mar 23, 2010 1:38 am Post subject:

Will a second DSC radio that is attached to the GPS but not programmed with the MMSI# still broadcast a distress signal with the vessel position? It would be a bummer if in an emergency one pressed the secondary VHF DSC button in a panic and it didn't broadcast for lack of MMSI. I was under the impression that the DSC signal would still transmit the lat/long.

Grumpy · Posted: Tue Mar 23, 2010 9:33 am Post subject:

Sorry for the confusion, I will try to clarify.

Your MMSI number is a unique identity for that boat and owner. ie. you do not get two of them unless you want to confuse your potential rescuers.

Yes, both radio's really should have the same MMSI # in them otherwise it would not be worth having DSC capability on the second radio.

IF you do that, be sure you have read the fine print in the manual about turning off one of the radio's ability to respond to DSC requests and sound alarms. You want to turn all that off but leave its ability to transmit a mayday with GPS data. The difficulty is figuring that out from the radio manual.

If you do not or cannot (because the unit is not capable) do this, both radio's will sound alarms and try to answer and (after you have shut down the engines beacuse you thought they were overheating/out of oil etc etc) you will spend an interesting moment or two trying to shut them both off and/or answer the call, change your underwear, and recover from the heart attack, spilled drink etc.

AIS adds a whole 'nother dimension in that you will now have a yet another source of alarm on the radio. Believe you me it is very annoying coming into a place like Friday Harbor and having your AIS "dangerous target" alarm going off constantly simply because you are heading towrds a number of moored boats that are transmitting their position on AIS. I have turned it OFF and would probably only ever enable it in an offshore crusing situation in poor visibility. For me, on a small boat, AIS is just another tool to help me identify a "blob" on radar or to contact a specific vessel unambiguously which is why I like the concept of being able to press one "call" button and call a specific vessel via DSC.

I don't know about all radio models but my Standard Horizon rings like a telephone for DSC calls and wails like a banshee for mayday.
I have 2 from SH and they both have totally different procedures for setting up the alarm / response functions.

For me the matrix 2000 without the built in AIS seems a good solution with my set-up.

Merv

hardee

David, Sorry, My bad here:

nimrod · Posted: Thu Apr 08, 2010 4:23 pm Post subject:

Just an FYI regarding Lowrance support service and ability of LCX-20c chartplotter to display AIS.

I emailed Lowrance Support asking if this chartplotter would be compatible with the Standard Horizon GX2100.

1. it took Lowrance 2 weeks, but they did finally respond

2. the LCX-20c will not work with the GX2100.

jd

Larry H · Posted: Fri Apr 09, 2010 2:43 am Post subject:

On the subject of installing two DSC radios,

I asked Standard Horizon tech support about this and here is my question to them and their reply.

thataway · Posted: Sat Apr 10, 2010 12:14 am Post subject:

Larry,
Is it even possible to buy a new non DSC radio from Standard Horizon (or any manufacturer)--in fixed mount? Certainly there are hand helds, which are non DSC--although there are more DSC hand helds VHF.

Adeline · Posted: Sat Apr 10, 2010 12:25 am Post subject:

Larry H · Posted: Sat Apr 10, 2010 2:44 am Post subject:

Bob, Pete,

Funny you should ask!!

Until today the Standard Horizon web site showed an Eclipse VHF without DSC. however in looking at the SH website tonight, the Eclipse has been replaced with the Eclipse+ which has the SC101 DSC.

Pete,

If you are serious about that radio needing a good home, send me a PM.

Larry H

hardee · Posted: Sun Apr 11, 2010 2:52 pm Post subject: hope nothing else is going on

Larry,

Thanks for putting that SH communication up here. Good Questions. One possibility would be to turn off the other radio, (not the one you are pushing the DSC emergency button on) and just having one radio on, but then you loose the feature of having a second radio functioning. Maybe turning it off, then back on after the DSC signal is out would work. One radio is going to go to Chan 70 for DSC and the other would be able to be set back to 16 for USCG communication.

Sure hope nothing else is going on that needs attention Embarassed

Harvey
SleepyC Moon