Radio antenna wire down mast

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kitcat
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Radio antenna wire down mast

Post by kitcat »

I want to fit a radio antenna to my masthead before the boat goes back into the water, which means running some wire down the length of the mast, which is, I believe, foam filled, or at least top and bottom are.

Can anyone who has done this let me know what method they used and any pitfalls please?

Paul.
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Crikey
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Re: Radio antenna wire down mast

Post by Crikey »

Paul, I did this last spring for a radio coaxial, as well as extra wires or spreader lights and an anchor light. Instead of plastic pipe I used joined (soldered) 1 1/2" copper water pipe. About three lengths I think. At the end I hacksawed pointed teeth, with half slightly bent inwards and the other half very slightly outwards (further sharpened with a file).
The object is to gradually digest small amounts into the end of the copper pipe which will have to be blown, or poked out from the other end. A tap and turn technique works fine. I also used some WD40 for lubricant to speed things up. Either way progress is not going to be very fast - just steady.
Using plastic, the joint ridges - even when facing away from the direction of travel - are too large to avoid resistance by the foam you are boring through. I actually used most of the copper afterwards for a house project.
Make sure you pull extra wires and/or a drawstring line to simplify future possibilities. Installed uncut cable ties every two feet can reduce the downward pull gravity has on the wires, which over time can break conductors.
Ross 8)
kitcat
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Re: Radio antenna wire down mast

Post by kitcat »

Got it, rather like drilling for oil, except going along the mast. Thanks Ross.
Hodag1
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Re: Radio antenna wire down mast

Post by Hodag1 »

Kitcat,....I did this last summer. The top 20ft of a 26M mast is foam. I started by removing the mast cap, I then drilled the first several ft. with a I inch, 4 ft., long electrician drill bit. I then took a 1 inch hole saw, cut/ground off the arbor and glued the cutting end to a 1 inch diameter 10 ft. section of thin wall metal electrical conduit. I put this into the starter whole and used vise grip pliers to turn it pulling it out often to remove the foam. Once that first 10 ft. was done I then joined a second section of 10 ft. conduit to the first section using the same union/coupler that electricians use to join sections, I used pop rivets. Repeat the processes with a 3rd 10ft. section. You will need silicone to lubricate it and a large pipe wrench to ultimately turn your 30ft. long hollow drill bit. I did it with the mast on the boat cradle using a step ladder. It took the better part of a day with a friend to help me.
I traced the mast tip onto a 1inch thick piece of solid oak, cut it and sanded it down to fit inside the mast tip. I cut and shaped a 5/16 piece of Plexiglas to serve as a mast cap as I wanted to add an anchor light to the top of the mast at the same time. The antenna I chose is a Shakespeare 5445 with wind vane that mounts to the rear of the new Plexiglas mast cap and is easily removed for trailering. I regret not taking pictures of the hole drilling process now but can send you a picture of the mast cap with light. Boat is in winter storage. Good Luck!
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AlaskaMan
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Re: Radio antenna wire down mast

Post by AlaskaMan »

I have the 26X so no foam in the mast. I did this last year and mounted my VHF-FM at the top of the mast. I didn't run the coaxial thru any pipe and I don't suffer from any "slap" of the wire inside the mast. Either that or all my u/w time with the USCG made me ignore such sounds....
:macx:
tvanbeck
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Re: Radio antenna wire down mast

Post by tvanbeck »

I also did this last year. To keep the wires from slapping the side of the mast I put a zip tie every foot or so and did not cut the end off. The excess holds the wire in place in the mast.
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