VHS DSC and GPS

7

[70521]

Well-Known Member
Joined
31 Aug 2011
Messages
22,412
Visit site
Camelia came with a NASA Marine SX35 DSC radio and an ancient Eagle IntelliMap 320, as used by Noah in the Ark. There is a lead on the radio to take a GPS data feed and I am wondering if I can splice it into the cable coming from the GPS mushroom as there are no plugs for it on the Eagle IntelliMap 320? Oddly, the Eagle IntelliMap 320 does not work ashore but does at sea!
 
Depends whether the GPS mushroom is merely an antenna, connected to the receiver via a coax cable, or is in fact an antenna and a receiver combined, connected to the display via a multi-core NMEA cable.

Given your biblical description of it, I would have assumed your system to be the former type. However, the instructions do talk about an external receiver, so it could possibly be the latter (I couldn't be sure from the manual).

What kind of cable connects the two?

Pete
 
Camelia said:
Camelia came with a NASA Marine SX35 DSC radio and an ancient Eagle IntelliMap 320, as used by Noah in the Ark. There is a lead on the radio to take a GPS data feed and I am wondering if I can splice it into the cable coming from the GPS mushroom as there are no plugs for it on the Eagle IntelliMap 320? Oddly, the Eagle IntelliMap 320 does not work ashore but does at sea!
Click to expand...

Your radio will require the simplest NMEA GPS data feed, but form what I could find on the 320 GPS, it does not have any facility to send that data. Later Intellimap machines do have the NMEA output, but not the 320.
The antenna (mushroom) is simply a RF antenna to read satellites, there is nothing to generate NMEA in that device itself.

You can get some simple GPS / NMEA receivers these days on Ebay, many are USB but some could be adapted to provide DSC data..

Graeme
 
Thanks Pete and Graeme, I thought that might be the case.

I have a Garmin 60SXMap that I can get a cable to run it off the boat batteries, I can use that cable run a data feed from from the GPS to the radio.
 
Another possibility would be a BR355 GPS "puck": http://www.ebay.co.uk/itm/NEW-Globa...3?pt=UK_In_Car_Technology&hash=item337c7b2341

It has a "PS/2" style plug on it, but this is irrelevant as the actual wiring is not PS/2. So you cut the plug off, and you have a black and a red wire for power, and a green wire carrying NMEA data (plus a couple of others you can cut off and ignore). The only downside to this approach is that the power it expects is 5v rather than 12v, so you need a small power supply circuit (a regulator chip and two small capacitors will do nicely). Run a couple of extra wires from the same boat circuit as the radio, to power it, and connect the green wire (and the negative, if required) to the radio's NMEA input. This gives you a nice self-contained GPS feed for the radio, independent of anything else.

The BR355 will work fine through a fibreglass deck, just tuck it up inside the headlining somewhere, or glued to the deckhead behind some trim.

Pete
 
prv said:
Another possibility would be a BR355 GPS "puck": http://www.ebay.co.uk/itm/NEW-Globa...3?pt=UK_In_Car_Technology&hash=item337c7b2341

It has a "PS/2" style plug on it, but this is irrelevant as the actual wiring is not PS/2. So you cut the plug off, and you have a black and a red wire for power, and a green wire carrying NMEA data (plus a couple of others you can cut off and ignore). The only downside to this approach is that the power it expects is 5v rather than 12v, so you need a small power supply circuit...
Click to expand...

There's a YAPP coming to do just that. It might even have a box this time.
 
AngusMcDoon said:
There's a YAPP coming to do just that. It might even have a box this time.
Click to expand...

Good-o - seemed like an obvious target to me. I've made my own on a sliver of veroboard, with the GPS wires soldered to one end and a 3-way bank of screw terminals on the other. I didn't bother with a box but just wrapped it up in fabric "looming tape".

I reckon if you make a similarly neat PCB, include the GPS unit so it's already soldered in place, and pop the adaptor in a nice box, you'll have a perfect little niche product to suit a lot of people.

Given the target audience, it's probably worth putting four terminals on your version, with the power -ve separate from the NMEA -ve even though they're connected together internally. "Power goes in this side, GPS comes out that side" is easier for some people to get their heads round!

Still the challenge of naming the NMEA terminals in such a way that people don't try to connect them to their radios' outputs/across two separate channels/other standard cockups :). Perhaps an hour or two's research with downloaded manuals and include a sheet of numpty instructions for common radios?

Pete
 
AngusMcDoon said:
There's a YAPP coming to do just that. It might even have a box this time.
Click to expand...
Sounds interesting :)

the lead from the radio comes with five (I think) coloured wires and a simple GPS device on the end would be ideal.

Looking at the ebay link its much, much cheaper than the Garmin lead!
 
Something like this...

97379300.jpg

81398888.jpg


with LM2913 for U2 and this for a box...

1526717-40.jpg
 
Last edited:
AngusMcDoon said:
There's a YAPP coming to do just that. It might even have a box this time.
Click to expand...

This is music to my ears - and my wallet!

I would really really like that solution for an external GPS NMEA feed, to go into a Stanard Horizon VHF + AIS.

Then if the gods are kind, a YAPP Multiplexer, so we can merge the seperate AIS and GPS signals into a USB-feed to a computer or Linux/Android Tablet with OpenCPN software.
 
Boreades said:
For anyone nervous of ordering from China via eBay, it looks like Globalsat has a UK distributor in Edinburgh. I've emailed them but have no idea of the price from them yet. See http://www.globalsat.co.uk/product_pages/product_br355.htm
Click to expand...

Most of the items I've ordered from China were through Ebay, and very good value at that. It takes typically 2 weeks for small items to arrive, and I've never had any bother with Customs. I've ordered direct from businesses in China and received very good, polite service I have to say. Unless you need it tomorrow, it's well worth a couple of weeks ;)

Graeme
 
pagoda said:
Most of the items I've ordered from China were through Ebay, and very good value at that. It takes typically 2 weeks for small items to arrive, and I've never had any bother with Customs. I've ordered direct from businesses in China and received very good, polite service I have to say. Unless you need it tomorrow, it's well worth a couple of weeks ;)
Click to expand...

I'd second all of that, except that sometimes it can be more than two weeks (but they do give you an estimated date). I've had no trouble ordering smallish electronic stuff and other goods from China via eBay, and I've done so quite a lot in recent years.

Pete
 
AngusMcDoon said:
Can't you use a RS232 to USB dongle with 2 serial ports? OpenCPN can cope with GPS and AIS data coming in on different COM ports at different baud rates.
Click to expand...

Good idea! Which makes me wonder, as the Globalsat dongle is so cheap, why not get both versions?
e.g.
1) BR-355 with PS2 to feed the Standard Horizon 2100E VHF+AIS or other existing marine instruments
2) BU-353 with USB to plug the GPS data directly into the computer/tablet

Then I only have to feed the AIS data from the SH radio via NMEA to the computer/tablet - like this adapter from All Gadgets?
£23

At these prices, I think I can get approval from my Financial Director (Mrs Boreades)
A new VHF radio has already been approved.
 
You must log in or register to reply here.

Share this page

Top