Radar connection, chocblock good enough?

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samwise

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We will have to de-rig this Autumn and that will involve separating the radar cabling that currently runs continuously from mast to instrument.
All the other stuff is on deck plugs, but I have found that deck plugs in multi pin format always seem to suffer badly from corrosion and consequent failure ( albeit temporary) of the unit. Therefore a connection inside the boat is desirable.
I can't really unthread the cabling back from the chart table because that will involve taking down at least half the headlining which, on a Westerly , is a PIA.

I have spoken to the professionals and they say they use simple chocblock connector strips -- which seems a bit Micky Mouse to me, but they say it works. Ideally some sort of waterproof male/female plug and socket arrangement that I can pull through the deck gland aperture would do the job, but I fear they are on the expensive side.

Any ideas/ suggestions welcomed
 
Precisely that was about my JRC 1000 which doesn't work; I thought it might be because of the chocblock but it appears to be common practice so my problem might be elsewhere
Erik
 
My Raymarine C80 to Radar connection is done in this way.

When I installed it I asked Raymarine they said they could sell me an expensive connector that would probally not fit through my deck anyway or I could use Choc Block is 100% sure it was in a dry location.

I used the Choc Block in the back of a cupboard and no problems so far.

Steve
 
Isn't it time the marine electronics industry recognised that at some stage, everyone is going to have to break the radar cable at some stage?
Choc blocks seem to work fine, but it's not very elegant. Surely the manufacturers can see that all radar plugs are too big to fit through a deck gland.
 
Choc blocks have no place on a boat, well except for emergency repairs,
They are made from inferior materials and the screws are usually only plated steel.

I daresay MOD spec ones might be OK, but ordinary ones from B&Q just turn to a rusted blob in no time. Better to twist the wires together and solder them, then wrap in amalgamating tape. (12v soldering irons are available)

Alternately Maplins or your local motor factors stock a range of connectors
 
I have choc blocks on my Westerly and they have been OK for 13 years now. However, rather than put one wire in from each side, the wires are twisted together first, doubled, and then effectively clamped in one side of the block.
 
Choc blocs are fine, as long as you are 100% sure that no water can get to them. A coating of vaseline, applied after the connections have all been made, will help to keep corrosion at bay.

It's also worth regularly checking any exposed radar cable between mast and deck - not a problem if you have a keel-stepped mast with the cables exiting below the deck, but any exposed cable is subject to u/v degredation, and the outer sheath will harden and will eventually split and let in water. Once salt water gets into the screening, it will travel a long way, possibly several metres.
 
Thanks for all those helpful replies. Hopefully the mast will not have to go up and down like a yo-yo, but I wanted to have an arrangement for the cabling where I did not have to keep twisting wiring together and undoing it again. I was looking for a rather better solution and I think I may have found it.

Index Marine do a plug together choc block strip (Part No F-3246 12 way strip) i.e. you wire up both sides and then just clip together to make the connection. I reckon that if I make it up in two sections it will go through the hole in the deck and the gland casing. Being Index I would expect it to be a marine grade job and if I waterproof and tape it up properly it should be fine.
 
When I installed my Furuno radar I had no option but to break the cable and re-connect below deck. I was advised by a professional that a good quality chocolate block connector, inside a water resistant box would be OK, and so it has proved.

Whenever the mast is unstepped the cable has to be disconnected, so soldering, twisting the wires together, or other semi-permanent solutions are not ideal.

I was also advised to use small crimp terminals on the tiny wires in the multicore cable. These are inexpensive and can be crimped flat with ordinary pliers. They protect the wires from damage by the screws in the chock block.

Found some similar crimp terminals here:

http://www.ishop.co.uk/item/shopslimited/785.402.html
 
I'm with Billcowan on this ... choc blocks have no place anywhere, let alone on a boat, other than as a temporary fix pending doing a proper job of it.

Any professional that fitted choc blocks to anything of mine would get a right ear bashing too - amazed that any pro would suggest such a thing. Hmm, OK, perhaps not so amazed but definitely not impressed. OK, so not likely to happen given that two thirds of the owners of Brigantia are professional electrical / electronics engineers but you know what I mean!

There are infinitely superior methods of making connections to choc blocks. I would use waterproof crimp connectors for preference for a permanent job or a waterproof plug and socket if it needs to be disconnected more than once in a blue moon

If it absolutely has to be disconnectable to bare wires then I'd make up a waterproof junction box (if I couldn't find such a thing to buy) using a length of bus bar inside a waterproof box with waterproof cable glands. A faff to make up but if a job's worth doing ...
 
Brigantia said:
If it absolutely has to be disconnectable to bare wires then I'd make up a waterproof junction box (if I couldn't find such a thing to buy) using a length of bus bar inside a waterproof box with waterproof cable glands. A faff to make up but if a job's worth doing ...
Click to expand...

This sounds remarkably similar to my set up - just substitute top quality choc block, with short pin wire terminals, for bus bar. Is that such a bad thing?

"Waterproof" junction boxes like mine are easy to find, but I reckon "water resistant" might be a more accurate description. Anyway, the connection is under the deck, not out in the weather.

If I could find an alternative 9-way connector, one half of which would pass though my cable gland on deck, I would probably use it, but I doubt that such a thing exists

However, four years on, so far so good.
 
I do not trust chocolateblocks.
If you mast is not unstepped often a good option is to solder the joints and protect them with glue lined heat shrink. When the mast is unstepped the joint is cut. You loose a couple of inches in cable, but for most installations the equipment will be retired well before the cable becomes too short.
 
Where I am, boats stored ashore for the winter MUST unstep their masts.
This is a pain, but necessary in the kind of weather conditions we regularly experience.

As the joint in the radar cable is made and unmade every year, it isn't a case of out of sight, out of mind. FWIW I have always found the connections tight and corrosion free. I am fussy about these things and if I had a practical alternative, that doesn't involve repeated and tedious shortening of an expensive multi-core cable, I would give it serious consideration.

More suggestions welcome.
 
JayBee said:
This sounds remarkably similar to my set up - just substitute top quality choc block, with short pin wire terminals, for bus bar. Is that such a bad thing?.
Click to expand...

Yes!

'Cos there is no such thing as "top quality choc block". There's cheap chocblock and expensive chocblock and they're all carp chocblock!

Even setting aside the perenial problems of rusted up screws, I've lost count of the number of times I've tried to undo choc block connections only to find that the screw has stripped the threads of the block or fallen out completely or otherwise ceased to make a good connection.

But to be fair, below decks inside a terminal box protected from damp it's likely to be adequate for the purpose - I'd personally spend a few pennies more on a proper bit of busbar but then I'm somewhat of a perfectionist when it comes to electricals (it's the way I was taught, only the best was just about good enough and even then only just)
 
Brigantia said:
Yes!

'Cos there is no such thing as "top quality choc block". There's cheap chocblock and expensive chocblock and they're all carp chocblock!

Even setting aside the perenial problems of rusted up screws, I've lost count of the number of times I've tried to undo choc block connections only to find that the screw has stripped the threads of the block or fallen out completely or otherwise ceased to make a good connection.

But to be fair, below decks inside a terminal box protected from damp it's likely to be adequate for the purpose - I'd personally spend a few pennies more on a proper bit of busbar but then I'm somewhat of a perfectionist when it comes to electricals (it's the way I was taught, only the best was just about good enough and even then only just)
Click to expand...

OK. Here's the Index Marine description of the choc block I use:

"A range of high quality 12 way connector strips. Each strip has nickel plated brass screws and inserts plus stainless steel cable leaf protection for better connections."

http://www.indexmarine.co.uk/connector.html

What magic metal are busbars and their screws usually made from?
 
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Boathook got the same advice as me from a Furuno agent. Have a look at any fishing port and see how many Furuno radar scanners there are, as opposed to, say, Raymarine.

These boats have a hard life and their electronics are for work, not play.
 
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