Any tips for swapping out a radar antenna?

[autumnbreeze27]

I'm replacing a Furuno radar antenna with a Raymarine unit. The radar is mounted on the mizzen. I was going to borrow a ladder to do it, because I have that luxury (we are in a slip and my dad has a ladder).

Any tips from those who have done it before?

I'm guessing I should rig a halyard to lower the old antenna and haul up the new one? Or just man it up and down the ladder?

Any tips on swapping the cable?

[barnakiel]

It maybe easier if you have something holding up the units as you work on the fittings. As you said, a halyard may do.

b.

[deblen]

I was in the business & this is how I did it.
Stand ladder quite vertical-place your toes at base of ladder legs & reach out arms length-you should be able to grab ladder.Tie a rope from bottom rung to mast.Go up carefully & tie top of ladder to radar mount or mast.
Don't cut the old cable-they have value-$150 on ebay.
Use slot screwdriver to unscrew 4 captive dome cover screws.Take cover down & put in cockpit.It will blow/slide off deck.
Unplug cable conns in dome,unscrew packing nut & remove cable from dome.
Ues a socket & ratchet to remove 4 dome mounting bolts.Don't be surprised if they are seized in alum. stand. Carry old dome down-they only weigh 25-35lbs.
Now you need a paper pattern of mounting bolts of replacement dome.
Drill new oversize (by 1/8") holes in stand.
Carry & mount new dome,without cover.Use Neversieze on bolts.
Tie a piece of heavy cord to old cable.Tape the plugs on old cable so the result is as small as you can make it.Pull old cable with cord out of mast.
Reverse proceedure to pull new cable up.Don't forget to start at display location with cable,so that display plug doesn't have to be fed back thru holes it won't fit thru.
If old cable was cut, with a plug/socket arrangement near base of mast,you are in for a treat.My suggestion is to hire a tech to do this soldering job & supply multi pin conn. If you decide to do it yourself,I would suggest a terminal strip(or 2) & use red crimp eye terms. Mount term.strip(s) inside boat.

Good luck /Len

[autumnbreeze27]

Originally Posted by deblen

I was in the business & this is how I did it.
Stand ladder quite vertical-place your toes at base of ladder legs & reach out arms length-you should be able to grab ladder.Tie a rope from bottom rung to mast.Go up carefully & tie top of ladder to radar mount or mast.
Don't cut the old cable-they have value-$150 on ebay.
Use slot screwdriver to unscrew 4 captive dome cover screws.Take cover down & put in cockpit.It will blow/slide off deck.
Unplug cable conns in dome,unscrew packing nut & remove cable from dome.
Ues a socket & ratchet to remove 4 dome mounting bolts.Don't be surprised if they are seized in alum. stand. Carry old dome down-they only weigh 25-35lbs.
Now you need a paper pattern of mounting bolts of replacement dome.
Drill new oversize (by 1/8") holes in stand.
Carry & mount new dome,without cover.Use Neversieze on bolts.
Tie a piece of heavy cord to old cable.Tape the plugs on old cable so the result is as small as you can make it.Pull old cable with cord out of mast.
Reverse proceedure to pull new cable up.Don't forget to start at display location with cable,so that display plug doesn't have to be fed back thru holes it won't fit thru.
If old cable was cut, with a plug/socket arrangement near base of mast,you are in for a treat.My suggestion is to hire a tech to do this soldering job & supply multi pin conn. If you decide to do it yourself,I would suggest a terminal strip(or 2) & use red crimp eye terms. Mount term.strip(s) inside boat.

Good luck /Len

Thanks Len! Great info!

[cabo_sailor]

I'm having my old Raymarine radar replaced with a new Garmin. The old Raymarine has a cable about 1" thick. The new one will basically have an Ethernet cable. Much thinner. You will probably find the same which should be piece of cake to install using the old cable as a messenger.

Rich


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[SailFastTri]

It's very likely the old cable is secured by cable ties internally and/or wrapped and intermingled with other cables inside the mast. If that's the case you'll need crane assistance to lower the mast to horizontal, and sort it out.


Not definite.... All I'm saying is that you should be prepared for that possibility. Good luck.

[cabo_sailor]

Yep sailfast, I forgot that aspect. Many years ago I had the stick pulled and rewired thru conduit. So wire ties are not an issue for me. But they sure might be an issue for the OP.


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[autumnbreeze27]

Got the antenna down (thanks to my dad) and the problem has been the damn cable. My guess is it's in conduit and I'm going to have to either tape the end really good or cut the connectors off.

Can't ever have a project go quick and painless!

[deblen]

Originally Posted by autumnbreeze27

Got the antenna down (thanks to my dad) and the problem has been the damn cable. My guess is it's in conduit and I'm going to have to either tape the end really good or cut the connectors off.

Can't ever have a project go quick and painless!

You are learning about boats!

It came up thru the conduit so....with any luck??
Unless there were more wires for other stuff added to conduit after radar cable-that happens.
Best you can do is a smooth tape job.The plugs can be laid in parallel to the cable,one at a time & you can make the tape job as small as the OD of the cable.If that doesn't work,probably have to cut cable.Leave at least 6" of sheathed cable-it can be spliced inside dome if reused.
Be careful pulling cable thru conduit-take it slow-you can chafe the other wires in conduit if you go too fierce.Use some liquid soap for lube.
What model Furuno are you removing?
Is the cable on your replacement small dia? Just wondering what kind of trouble you may have pulling new cable up.Be gentle & patient. / Len

[autumnbreeze27]

Furuno 1731 mk3 coming down and Raymarine rd18hd. Not looking forward to working on this tomorrow!!

After I get the cable out I can pull the new cable, but still have to make an adapter plate before I can mount the antenna. And then there's the fact I have a 10m cable and I'm not sure if the distance I need is 10m or 10.2m!

[deblen]

Originally Posted by autumnbreeze27

Furuno 1731 mk3 coming down and Raymarine rd18hd. Not looking forward to working on this tomorrow!!

After I get the cable out I can pull the new cable, but still have to make an adapter plate before I can mount the antenna. And then there's the fact I have a 10m cable and I'm not sure if the distance I need is 10m or 10.2m!

0.2 of a meter-that's cutting it close.Deal with that when you get cable inside boat.
Get some marine aluminum 3/16" plate will be heavy enough.Very easy to cut with circular,table,jig saw,etc.Wear safety glasses though.
You may be able to use 1/4" alum. flat bar instead.There is no need for dome to sit on full plate.
Keep plugging away.

[autumnbreeze27]

I haven't tried pulling the new cable (kinda fearful of what I will find), and now I'm trying to figure out the adapter plate.

I might go looking for some scrap AL plate tomorrow, I don't think bar will as the holes are too far out of line.

[The Smokester]

Originally Posted by autumnbreeze27

I haven't tried pulling the new cable (kinda fearful of what I will find), and now I'm trying to figure out the adapter plate.

I might go looking for some scrap AL plate tomorrow, I don't think bar will as the holes are too far out of line.

Is your mast keel or deck stepped? If deck, the feed through the deck may be plugged or sealed preventing you from pulling the lines through the deck. Mine is that way and I'm stuck pulling the mast.

[autumnbreeze27]

It's keel stepped I just know it's going to be a tight fit.

I'm thinking about making my adapter out of 3/8" starboard or hdpe... any reason that would be a bad idea?

[Bruce Beard]

My then girlfriend (now wife) helped me install a radar on my 32' sailboat, while at anchor, in Hadley's Harbor almost 20 years ago. Each of us took turns working up the mast and at the base until we succeded in getting that cable routed! It was a first time radar for the boat so we drilled holes and fished it through...
Amazingly, she still married me after that weekend...

A few years later, I upgraded the electronics and installed the radome on a Questus. Much easier installation!