vhs radio

[capeannfisherman]

Reading through all the new radios for sale is making me a little nuts. It seems that some can display the gps location of the boat you are talking to without any wiring or upgrades. If I'm reading this right the Icom IC M604 is one of these units.(Built in class D DSC) What does this mean?
Adrian

[21ftcc]

Digital Selective Calling (DSC) radio is the latest in marine radio technology. Digital Selective Calling is part of a global upgrade in maritime distress communications. Satellite and digital technology used for several years on commercial ships is now available to the recreational boater. DSC radios allow boaters to make ship-to-ship private calls and the DSC distress channel is currently being monitored by commercial ships.

The major advantage of the DSC radio is its ability to send an automatic "mayday" that identifies the vessel and also, when connected to a LORAN or GPS, can send the vessels location. The DSC radio operates much like an EPIRB that sends encoded "maydays" directly to satellites. The DSC radio will also continue sending the emergency signal if the skipper is disabled.

Another feature of the DSC radio is the ability to place private ship-to-ship calls (if you have sea tow, ship to shore to phone at home) and to other vessels equipped with DSC radio. Basically if you know the MMSI number of the radio you are calling only that vessel will receive you message. Just like using your cell phone.

MMSI -
Maritime Mobile Service Identities (MMSIs) are nine digit numbers used by maritime digital selective calling (DSC), automatic identification systems (AIS) and certain other equipment to uniquely identify a ship or a coast radio station. MMSIs are regulated and managed internationally by the International Telecommunications Union in Geneva, Switzerland, just as radio call signs are regulated.

Non-commercial users (e.g. recreational boaters) who stay in U.S. waters can obtain an MMSI through approved organizations such as BOAT US 1-800-563-1536, SEA TOW 1-800-4SEATOW, U.S. Power Squadron, and Shine Micro (primarily for AIS). Most of these organizations provide MMSIs at no charge even to nonmembers.

Although commercial ships over 300 tons are now required to monitor the DSC Radio reserved Channel 70 for distress calls, the US Coast Guard is still monitoring Channel 16. As the Coast Guard updates and upgrades there equipment, they should be monitoring DSC Channel 70 in many areas by 2002-3 and be fully functional and compliant by 2005-6. The USCG's equipment up grade will include:

* DSC capability to send or receive calls on channel 70
* Eliminate the 65 gaps in current VHF coverage in the US
* Provide direction finding capability to trace a garbled radio signal to within 25 miles
* Provide playback of VHF voice or digital calls
* Provide automatic tracking of USCG ships and aircraft on search and rescue missions

Now we just need a place to share MMSI numbers, Welder, Jetty????/

https://secure.seatow.com/boating_safet ... gister.asp

Adrian
If you need help setting it up or wiring it up just let me know.
Jason

[capeannfisherman]

Thanks, this helped. I will need help when I get the new one. Wire it up? I thought it was built in to some and needed no extra wiring.
Still confused about which radios do what, any ideas on a radio that is already complete and ready to just add power and antenna?

[21ftcc]

Oh yeah,I have a radio that I could wire into my GPS, and fish finder, then if I a mayday call came over, it would display the location on the gps, it would also display the the location when you would talk by DSC. The fish finder would let you record depth on the GPS.

[welder]

Adrian, you have a PM , you get to start the new forum.

[21ftcc]

Adrian,

Ok... I quickly read the manual for the Icom IC M604, as like my radio, a GPS unit will be needed to be connected to obtain GPS location during distress calls without having to manually input the gps location.

..."A Distress call should include the ship’s position and time
data. If no GPS is connected, your position and UTC (Universal
Time Coordinated) time should be input manually. They
are included automatically when a GPS receiver (NMEA0183
ver. 2.0 or 3.01) is connected..." pg18 M604 manual


Basically, make sure the GPS is connected... because who has time to input the time and N. E. when the boat is sinking or someone went over board.

...."When a GPS receiver (NMEA0183 ver. 2.0 or 3.01) is connected, the transceiver displays the current position and time. When no GPS receiver is connected, the transceiver displays the manually entered position and time.
A GPS receiver appropriate for the IC-M604 is not supplied from Icom. A GPS receiver with NMEA0183 ver. 2.0 or 3.01
format is required for position and time indication. Ask your dealer about suitable GPS receivers.
➥ When the connecting GPS receiver is compatible with several sentence formatters, the order of input precedence
is ‘RMC,’ ‘GGA,’ ‘GNS’ and ‘GLL.’ ➥ When sentence formatter ‘RMC’ is received, time indication
includes a date. Thus, the “UTC” or “Local” indication is not displayed. ➥ “??” may blink instead of position and time indications when the GPS data is invalid, or has not been manually updated after 4 hours. GPS information indication When a GPS receiver (NMEA0183 ver. 2.0 or 3.01) is connected, the transceiver displays the GPS information after pushing and holding [ENT] for 1 sec. When connecting GPS receiver is compatible with several sentence formatters, the order of input precedence is ‘RMC,’ ‘GGA,’ ‘GNS’, ‘GLL’ and ‘VTG.’..... pg 19 M604 Manual


Ok now with being said, wiring the radio and gps together is snap. However being the cheap company's they are, the wires are very small and tend to just break in giant hands. The wires will have to be soldered and heat shrink-d.

I bet your going ask what is NMEA0183, its just the language that the gps and radio talk together with. Like English, the format is like a sentence structure, Capital at the beginning, proper punctuation in the middle and a period at the end. Nothing you have to really worry about. Just have to make sure the GPS is NMEA0183 ver 2.0 or 3.01 compatible. If you want let me know what GPS you have and I will look it up to save you some time. If the GPS is 3.01 compatible you can plot gps location on the navigational device. Helps tell how far the distress call is being made from.



GPS RECEIVER/EXTERNAL SPEAKER CONNECTOR
➥Connects a GPS receiver for position and time indications. • An NMEA0183 ver. 2.0 or 3.01 (sentence formatters RMC,
GGA, GNS, GLL) compatible GPS receiver is required. Ask your dealer about suitable GPS receivers.
➥Connects a PC or navigation equipment (NMEA0183 ver. 3.01 sentence formatters DSC, DSE compatible) for plotting received other ships position data.
➥Connects an external speaker.
PG 46 Manual.

Ok what this all means is you will get a cable with a plug end to attach to the radio and a dead end with wires coming out. The wires can connect to the GPS, PC, and external speaker. as long as you determine which wires go to what.
The manual did not have color code for the wiring. So a little more detective work might be in order. i.e. get my multimeter out and see what wires go to what.

Well sorry for throwing so much at you.
Jason

[capeannfisherman]

Thanks I actually do understand your message. I have seen Johns' (alloy toy) hookup and as you mentioned many tiny wires to deal with. Someone needs to come up with a plug and play cable to connect gps to VHS.