electronics / data transmission help needed

[Birdseye]

Fitting a new radar into the boat to replace the failed unit. the new one has power wires to the scanner plus an ethernet cable (Simrad 3G radar). However try as I may I cannot feed the new cable through the headlining ( sadler type full internal lining) and the old radar cable is well and truly jammed in its trunking.

So - the old cable has lots of wires - could I put the necessary RJ whatever connectors on the end of these and use the old cable instead of the ethernet cable?

The alternative looks like having to erect a stern radar pole

 

[prv]

Normal ethernet uses two twisted pairs. If your existing cable has twisted pairs (rather than just "lots of wires") then there's a fair chance it might work. Problem is, you'll never know how marginal the connection is, and that is something that would worry me in conditions requiring radar.

Pete

 

[rogerthebodger]

What is the old radar so that the make up of the existing can be determined, then some may be able to tell you with technical knowledge of what you already have.

 

[pmagowan]

I would try and mouse the cable through. You should be able to take the end fitting off and reconnect. If the old cable is jammed could you use something like carbon lock powder to help it to slip through or perhaps even dome fairy liquid. It can be blasted through with an air pressure line. If it is jammed in a mess of cables then take them all out, pulling through a mousing line at the same time and then re thread them in a neat bundle.

 

[Birdseye]

the old radar is a simrad anritsu set from the mid 90s

I had thought about the fairy liguid trick - might yet try it.Problem is getting it all along the tube without a major mess at the other end.

 

[pmagowan]

the old radar is a simrad anritsu set from the mid 90s

I had thought about the fairy liguid trick - might yet try it.Problem is getting it all along the tube without a major mess at the other end.

Use an air gun on a compressor. If mixed with a bit of water it should find the way down well enough. You could try the carbon dust with a vacuum at the other end.

 

[Martin_J]

Assuming your old cable is Raymarine - then I think that it did contain twisted pairs.. I can take a look at an old Raymarine cable later. You'll just have to keep the pairs as pairs when you put the new plugs on.

As to the radar.. Yes - Good choice and it should then work with an RJ45 crimped onto each end. The other three wires (I seem to remember) are the red, black and yellow power/switching cables but your old cable loom should have sufficient for these and since power draw is less, they should be more than adequate.

I think the important part to first ascertain is whether or not the current cable has twisted pairs...

I did find the Radome strange - It's got the same mounting hole dimensions as the usual Raymarine radome - but when mounted the '3G' sticker is at the back of the dome.. (Unless you peel the sticker off carefully and stick it onto the front... ) Mounting the dome as supplied but with the 3G sticker visible from the front would end up with the cable entering the dome at the exposed front edge

 

[rogerthebodger]

I have one of those and the cable has all files of cores including twisted pair and coax but it would be a fiddly job to split and reconnect.

Whit bit is faulty the scanner or the display ?

 

[Birdseye]

I have one of those and the cable has all files of cores including twisted pair and coax but it would be a fiddly job to split and reconnect.

Whit bit is faulty the scanner or the display ?

Both. The scanner has been repaired but the display is beyond repair or so the various experts say.

The existing cable doesnt have twisted pairs but it does have very exntensive shileding to the outside and then inside are three pairs of coax cables ie an insulated central wire surrounded again by mesh which forms the second cable of each pair.

Have spoken to simrad and they say ( no guarantee) that their installers have come across this problem before and have used the old cable successfully. So I will give it a go.

It looks as if Bowman installed the cables into the headlining before uniting it with the deck and located the cables with a lump of grp effectively bondinged the cables in.