Which features do I want in a DSC radio?

chrisbitz

Well-Known Member
Joined
18 Sep 2012
Messages
509
Location
Bromley, Kent - Sail in Medway
www.freyacat.co.uk
Happy Christmas day everyone!

I've just passed my VHF course, and I wanna buy a DSC toy...

I know better than to ask "Which is the best one" :-) although suggestions are welcome..
What features should I look for?

Budget is about £100 to £200 ish?

I guess one with built in GPS is useful to save opening up the ipad to look for the GPS co-ordinates during a mayday...
The Radio cupboard is at the front of the cabin, so maybe one with a long lead and controls and speaker built into the mic?
are there any other features that I should be considering?
 
If its any help, I was in the same position, my plotter won't output to the VHF.
The set I went for is this one: http://www.piratescave.co.uk/?searchStr=gx1700e it's about the cheapest set I could find with built in GPS that has a decent reputation.
It's had very little use so far, but it always finds satellites quickly, has a 3 Year water ingress guarantee and seems good value.

I think (but check) that if you want AIS then you need to spend another £70.00 odd on top, depends if it's of value to you or not. It wasn't to me.

Hope that helps,

Chris
 
For some reason, built-in GPS is a rarity on VHF radios. However, it's fairly straightforward to connect up an NMEA GPS "puck" to give much the same effect.

If your radio will be mounted a long way from the cockpit then a remote handset would definitely be useful. Both wired and wireless ones exist; I prefer the former to avoid the issue of batteries.

If you think you might want AIS then built-in to the radio is a good simple way to get it, but perhaps you're not interested in that.

While you're doing the job, it would be a good idea to check the condition of the aerial and its cable and replace if dubious - these have a much greater impact on oerformance than the radio itself.

Pete
 
No need to be faffing about with iFads. You can get a 2nd hand handheld GPS off eBay for £30 or so, and hard wire it to 12V and to something like a Navman 7100 DSC.
 
Try making and receiving a DSC call on any radio before you buy it. Some are really easy and some are completely impossible so if DSC is what you're after then it's an important test to do.
 
No need to be faffing about with iFads. You can get a 2nd hand handheld GPS off eBay for £30 or so, and hard wire it to 12V and to something like a Navman 7100 DSC.

...or a new BR-355 GPS mouse for £23. This will have a modern chipset compared to an old GPS, which means it will work inside a boat, and start up quickly too.
 
A radio with a GPS inside is a nice feature.
But GPS needs a sight to the satellites. In my opinion a GPS receiver at the stern is a better solution.
If you like integration of functions, a AIS receiver is best located inside the radio.
Greetings, Wilhelm
 
...or a new BR-355 GPS mouse for £23. This will have a modern chipset compared to an old GPS, which means it will work inside a boat, and start up quickly too.
Would it work with a direct cable connection to the VHF as many cheap Garmin GPS receivers can, or would it require a USB-to-serial converter + power supply + some kind of magic to set the baud rate to 9600?
 
Would it work with a direct cable connection to the VHF as many cheap Garmin GPS receivers can, or would it require a USB-to-serial converter + power supply + some kind of magic to set the baud rate to 9600?

It needs a 5V power supply, nothing else. It is not a USB device. GPS over NMEA-0183 is 4800 baud, not 9600. It provides its data at the required 4800 baud.
 
Might give one of those a try myself then. An LM78L05 should do for the power supply, I'd have thought.

It would, although a LM7805 is not designed for noisy automotive applications with starter motors sending spikes down the line. This would be better as it's designed for automotive use (which is as close as you'll get for marine use)...

http://uk.farnell.com/on-semiconductor/lm2931z-5-0g/ic-ldo-volt-reg-5v-0-1a-to-92-3/dp/1130604

It must have the 10uF output capacitor to work though. There's a circuit diagram in the source zip file of the device I make for powering a BR-355 on this page...

http://yappelectronics.co.uk/GPPS.htm

You need DesignSpark to view it or I can upload a PDF.
 
It would, although a LM7805 is not designed for noisy automotive applications with starter motors sending spikes down the line.

For what it's worth, my br355 has worked fine for the last year with one of those.

(And with a foam-cored GRP deck over it too.)

Pete
 
For what it's worth, my br355 has worked fine for the last year with one of those.

You will be fine with a 7805; I have used one on an early YAPP and there have been no problems. However, an automotive electronic engineer had a squint at my design and commented that an automotive regulator would be very slightly more reliable. She said that there were a few failures in voltage regulators in cars in the early days of auto-electronics, for which the load-dump regulators were developed which can handle the noise, spikes and surges a bit better.
 
Large buttons, large display and keypad lock. What's easy to operate in a warm chandlery can be a nightmare in a bouncing boat with sausage shaped fingers.

Knobs to turn instead of buttons. Try selecting marina/club use channel 37 on a Simrad RD68 - which is otherwise a very good quality radio - needs a series of rapid button presses on different buttons, one button only activated by a menu. If you are too slow you fail. And a knob for squelch as well. I suppose it really ought to have DSC as well, though I've never used the function.
 
Try selecting marina/club use channel 37 on a Simrad RD68 - which is otherwise a very good quality radio

That's what was on Ariam when we bought her. I didn't really like it at all. Can't really put my finger on why (and I agree that build quality wasn't a problem) but I was very happy to replace it with a Standard Horizon.

Pete
 
Knobs to turn instead of buttons.

Presumably you mean knobs instead of up/down buttons. A keypad (with numbers) is *so* much easier than mucking about with up/down buttons or knobs for entering an MMSI. Makes a world of difference for DSC. I really don't know why so few radios seem to have one. In fact my ICOM 603 (which would have been out of budget here anyway) seems to have been discontinued and the 604 not made available in the UK. Buttons (with numbers on) definitely good for DSC.
 
It would, although a LM7805 is not designed for noisy automotive applications with starter motors sending spikes down the line.

But haven't we all followed recommended forum practice and fitted split charge systems? Starter is isolated from domestic power (which supplies nav and radio also) until engine is running and alternator up to relay switching voltage. Not same as car with single battery system.
 
But haven't we all followed recommended forum practice and fitted split charge systems? Starter is isolated from domestic power (which supplies nav and radio also) until engine is running and alternator up to relay switching voltage. Not same as car with single battery system.

Not all boats are as you describe. I have a pair of batteries in parallel making one supply which is used for everything, including engine starting.
 
Top