Cutting Radar Cable

[crms]

I'm looking at cutting a Furuno 1623 radar cable so that I can remove the antenna unit for security. Most of the wires do not seem to pose a problem and I could use a normal chocolate block inside a waterproof box. The only issue seems to be the shielded video cable. I was therefore thinking of making sure that there is a screen around the video cable to maintain the signal quality.
Any views??
TVMIA

 

[[2574]]

I've had to cut the cable on my newly installed Raymarine kit for the purposes of providing a joint for unstepping the mast. I've used a chocolate box arrangement inside the boat (it's dry) and have no problems with the radar signal. I've had to do the same with furuno kit on my previous boat - and similarly no problems.

I have had a joint get wet with salt water ingress - and the radar failed in less than 36 hours!

rob

 

[salamicollie]

Just use a choc bloc, even for the coaxes in the cable - make sure the overall screen is also connected through.

Done this with 2 radars before without any problems.

 

[pwfl]

I've cut the cable on my Furuno 1622 & joined it together again inside the boat in an ordinary junction box (is that what you mean by chocolate block??) - no probs with signal quality.

The only thing to be careful with is that one of the cables is a coaxial - you need to make sure you re-join both the outer shield, AND the inner core (or it won't work!).

Also, that inner core is very very fine & is quite fiddly to screw into the junction box without breaking it, although it certainly can be done.

If the 1623 is the same as my 1622, then you have to open up the radome to disconnect all the cables, which is basically why I cut my cable.

However, I have subsequently concluded that with a little forethought when laying up, it might actually be better to go up the mast & disconnect there.

In fact, if you are planning to take the mast down, it's not a bad idea to take the radome off anyway, as last time I had my mast taken down, the radome did actually get damaged - obviously it shouldn't , but accidents do happen.

The reason my thinking has changed is that I have thought of selling the radar, (or buying a different boat & taking the radar with me) & it would obviously be better if the cable was intact.

 

[jimboaw]

Removing the cable from the Furuno 1622 dome is very easy. In my case getting the cable back up the mast was the hard part!

 

[nedmin]

If you use connectors,get 2 identical ones,put one end of cable in one and other end in other.Get some single core copper cable, earth cable from power cable ideal, 4mm or 6mm ok .If you can solder, tin it to make a better connection,Cut the right number of pieces long enough to join the 2 connectors together.Then when you want to disconnect you dont disturb the wires only the stronger copper wires

 

[pwfl]

Just looking at your original post again - you want to do this so you can remove the radome easily (not drop your mast as I had obviously misread when I first replied) - If you're planning to remove the antenna anyway, then why not, as I have said, just disconnect the wires from the radome?

If it's the same as the 1622, then ok, it's a bit fiddly, but not that hard.

There is no point cutting £150 worth of cable if you don't have to.

Can I ask where you are? It's just that I've recently been cruising (& also left the boat laid up) in some fairly dodgy places (eg Venezuela), & there is nowhere where I've ever felt that concerned about my radome getting swiped (probably because it's pretty useless on its own, I suppose).

But then I do have mine halfway up my mast - perhaps yours is more accessible. But then again, I do have steps that make getting up my mast very easy.

 

[pvb]

Interesting website, Colin, and it's obvious you've put a lot of thought into Kei. I really don't think it's worth the effort of removing the radome for security - are you thinking of doing this every time you leave the boat? Before long, the connections will start to give you problems. Preferable solution might be to fix the radome with "security head" or Torx bolts. I have a Raymarine radome on a pole at the stern, and I'm not at all worried about its security.

 

[nedmin]

further to earlier thread, if you do it this way dont forget to make the wires that have chance of being "alive" the female connector.

 

[hightech]

Joining ANY coax cable with just choc block is a bad idea. Unfortunately, the signal for high frequency transmissions, radar video, GPS etc. travels down the plastic, this is why it is called a "dielectric".

The choc block can act as a big attenuator, so less signal (sometimes none!) will get through and performance suffers. Use a proper connector BNC, TNC etc. as they are designed to do the job.

Some of you will by now be thinking that I am talking a load of ....... Unfortunately I work in the industry and it is suprising of the number of units that get blamed for this type of poor installation technique. However, you all know better and will continue to choc block as it is cheap and mostly works.

Hightech.

 

[MarkJohnson12345]

We installed a Furono last year. I decided not to cut the cable to ensure good quality signals.

Taking the radome of is just four big bolts and one little one. Easy enough, and as said inside the radome its easy to disconnect the two connections.

I trunked the radar cable outside of the mast so removal is pretty straight forward if taking the mast down.

As for security, I guess some 15 y/o out to make a name for himself might have a go, or some wannabe after a quid or two from the next boat jumble might be interested. But I suspect any thief would go after easier meat.