Support for antenna cable and masthead lights???????

sailingdog · Mar 22, 2009

It really should be in a conduit and support to some degree. It isn't good for it to hang unsupported. BTW, if you run a PVC pipe up the mast as a conduit, it will stop the cables from slapping.

Rick Webb · Mar 22, 2009

You Must Support the PVC Also

Otherwise the PVC pipe will slap

Stu Jackson · Mar 22, 2009

Mast PVC Conduit Support

jackhartjr said:
Rick, how would you support the PVC pipe?

Jack,

Don Casey's "This Old Boat" book, newly revised and reissued, has an extremely well written and documented way to do just that. You may be able to find an older edition of the book for less $ (try www.abebooks.com or other sources). Essentially you pop rivet the PVC inside the mast.

Rick Webb · Mar 22, 2009

Dunno, I Took it Out

I found a length of 5 wire cable at West Marine in the mark down bin that was long enough for the mast. I kept looking at it every time I was there finally after six months they did an additional discount on all the mark downs and I had to spring for it. I did the cable tie deal with it and the VHF coax. Have not had the boat out since but it has to be quieter than the damn pipe smacking back and forth in there.

Rick Webb · Mar 22, 2009

The Cable Idea Has Some Merit

If you attach the cable at the top and bottom attach the wires to it then tension it up that could be a way to keep the wires from slapping.

The VHF cable can support itself if it is clamped somehow at the top to take the strain off of the connection.

Stu Jackson · Mar 22, 2009

Rick, it's called "mast slap"

and will drive you crazy if it does happen. You may be one of the lucky ones who, once installed, have the wires tight enough to do that, unless you've installed big cable ties to the wire (or used other proper attachment methods) as you put it in.

When we bought our boat in '98 (wow, over ten years ago - time flies when you're havin' fun!

) we had horrible mast slap which drove us crazy. It took three years before we got it together to redo our standing rigging and install a new ProFurl furler.

When we finally got the mast off, we found something very odd: all of the wires to the masthead except ONE were in the provided conduit; the usual assortment of masthead and steaming/deck light wires. The one silly wire that was making all the noise was merely a 14 or 12 ga. wire which was for the anchor light (which we never used, of course - we use a lamp oil anchor light on our backstay).

The anchor light was OEM. The PVC conduit was also installed at the factory. The factory guys blew it by putting one wire outside the conduit. There was plenty of room inside the conduit. Drats, they really blew it there.

How the PO lived with it is beyond me, because the slightest movement of the boat, whether at the dock or at anchor (he used the boat a lot at his dock with a few sails to the Delta, and we anchor out a LOT) drove us nuts.

I strongly urge whoever is doing this kinda stuff to do it right. There are many ways to do so, previously documented. Unless of course all you do is daysail and never go down below - but there will come a time...

I'm trying to tell you that simple tension top & bottom just will NOT do the job properly.

Your boat, your choice, your piece of mind, your brain...

dvideohd · Mar 22, 2009

foam floaties - as you find at WalMart and other places - have also been used to center the cables - and provide some flotation in case of knockdown..

--jr

Jenni · Mar 22, 2009

When I ran my coax cable up my mast i put foam pool noodles inside. We slid them down the inside of the mast this stopped any slaping noise from from the cable. You can get them at wally mart or Canadian Tire really cheap and they do the job quite nicely.

JIM B · Mar 22, 2009

What I Did

was to drill a hole in the side of the mast just below the where I mounted the antenna bracket. The cable comes out of the mast (through a grommet) at a 90 degree angle and then connects to the bracket for the antenna. I don't think there is any chance or inclination for the cable to pull out because of the friction at the 90 degree bend.
Also, I strongly recommend the long wire ties or pvc conduit.
Hope this helps and good luck.

Don S/V ILLusion · Mar 22, 2009

jackhartjr said:
I do not want to screw the coax in from under the masthead and have 23 feet of coax hanging there by the fitting under its own weight.
Jack

Why?
In 50 years of hanging coax off my ham radio antenna tower, it has never been an issue and the coax is suspended, totally exposed to ambient conditions, in lengths of approx 40 ft between the crank-up sections of tower without any problem or elongation. It's a non-issue assuming you are careful about chaffing and not suspending the coax totally from the connectors.Coax connectors should not bear any weight or torsional forces regardless of whether you attach the coax somewhere along it's length as you seem to intend - simply grommet and loop and you will be fine.

Rick Webb · Mar 22, 2009

Cable Tension

The cable I think we were talking about is an extra piece of stainless steel wire run inside the mast pulled tight ( this is the deal breaker can it be taught enough to not slap against the mast itself) then all of the other wires secured perhaps zip tied to it. It might work if you can get it centered and taught enough.

To secure the wires to the top of the mast and take any tension off the connections I put an eyebolt inside the mast attached to the cap. I ran my wires through it added a couple of pieces of heat shrink and a hose clamp to keep it from falling back through the eye bolt. The wire will have no trouble supporting itself for that lenght. the conection probably would have too but just to be sure.

The noodles work well unless you have internal halyards

Alec · Mar 22, 2009

I have used the wire tie method sucessfully on a 34' long mast. It even had internal halyards (my initial big worry) & is still working fine seven years later. I installed four ties pointing 90 degrees apart every 18". Totally silenced the wires in the mast.