When the weather warms up I'll be putting in a VHF cable from the top of the mast of my Tanzer 26. It seems there are two ways to go: (1) down the mast, or (2) taped to the backstay. The only disadvantage that I can see to taping it to the backstay is that it would look lousy -- and maybe some windage. If I run down the backstay, I can go with a single length of 50' stock RG8-X complete with PL-259 connectors on each end -- right from the radio to the antenna. I'd drill a large enough hole in the top of the transom to get the connector through, and plug it with a slit rubber stopper with a hole drilled in the center. There would be no worry about water doing damage, because the top of the transom is not cored. This would be easy to remove and install each year. The cable could run straight or have gentle bends (desirable) right to the back of the VHF transceiver. If I come down the mast, I have to go through the cabin overhead (cored), and an easily removable slit plug wouldn't be sufficiently water tight. Therefore I'd need connectors to make a break as the cable went through the deck. I don't see anything specifically for this in catalogs. I'd have to get the cable inside the mast, prevent chafing at the entry holes, cut the cable to exact length down the mast, and so on. So going down the mast looks like a real project. Further, the extra connectors would mean some power loss, and an opportunity for corrosion. So coming down the backstay would be much easier, and better electronically -- but I don't know that I have ever seen it. Is that only because it looks lousy, and nobody builds boats that way?
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The way I did it
Running it down inside the mast is really the way to do it.It's not as complicated as your makingit out to be. From the top of the mast down,here's how I did it.Mount the antenae.Drill a small hole just below the top of the mast slightly larger than the coax diameter.Slide a rubber grommet over the coax and slide it up to the connecter.Now your going to put zip-ties or wire wraps about every 1 to 2 feet on the coax.This will keep the coax from banging around and drive you nuts when your trying to sleep.Now push all the coax down into the mast until you only have the grommet and the connecter.Push the grommet aroung the hole so that the coax doesn't chafe.Connect the coax to the antenae .At the bottom of the mast you will drill a duplicate hole and leave about a foot or so of coax coming out of the mast.Now go inside your cabin and figure out where you want the cable to come in.MAKE SURE that both the inside and the outside are free from obstructions. West Marine and Radio Shack sell coax cable deck fittings.The West Marine part numbers are 117283,123851,540740,540732.This is the part that will keep the water out.You will need a connector part number pl258-g or 3757630.You will also need two male connectors #3757747. I gave part numbers for the gold fittings as there are more corrosion resistant.This way all you have to do is unscrew the connector at the base of the mast when you un step it.I hope this helps.
Running it down inside the mast is really the way to do it.It's not as complicated as your makingit out to be. From the top of the mast down,here's how I did it.Mount the antenae.Drill a small hole just below the top of the mast slightly larger than the coax diameter.Slide a rubber grommet over the coax and slide it up to the connecter.Now your going to put zip-ties or wire wraps about every 1 to 2 feet on the coax.This will keep the coax from banging around and drive you nuts when your trying to sleep.Now push all the coax down into the mast until you only have the grommet and the connecter.Push the grommet aroung the hole so that the coax doesn't chafe.Connect the coax to the antenae .At the bottom of the mast you will drill a duplicate hole and leave about a foot or so of coax coming out of the mast.Now go inside your cabin and figure out where you want the cable to come in.MAKE SURE that both the inside and the outside are free from obstructions. West Marine and Radio Shack sell coax cable deck fittings.The West Marine part numbers are 117283,123851,540740,540732.This is the part that will keep the water out.You will need a connector part number pl258-g or 3757630.You will also need two male connectors #3757747. I gave part numbers for the gold fittings as there are more corrosion resistant.This way all you have to do is unscrew the connector at the base of the mast when you un step it.I hope this helps.
go in the mast
I'd definitely recommend going inside the mast. I've done it on more than one boat and it's not hard. The coax is protected and you'll have less problems with it. On the backstay it's exposed to the elements and will get banged around a lot. There is also more weight up high and the windage effect. As mentioned, put tie wraps around it every few feet. PL259 threaded barrels are easy to install through the deck. I did mine by tieing a wrench to a string and dropping it down the mast inclined at an angle. I actually stood on top of our barn to make it easy. Then I tied the string to the coax and pulled it through.
I'd definitely recommend going inside the mast. I've done it on more than one boat and it's not hard. The coax is protected and you'll have less problems with it. On the backstay it's exposed to the elements and will get banged around a lot. There is also more weight up high and the windage effect. As mentioned, put tie wraps around it every few feet. PL259 threaded barrels are easy to install through the deck. I did mine by tieing a wrench to a string and dropping it down the mast inclined at an angle. I actually stood on top of our barn to make it easy. Then I tied the string to the coax and pulled it through.
thread the mast fast
with a shop vac and do it on the flat. Get 60 feet of string and tie a small puff on one end, put it in one end of the mast and suck the puff out the other end.
with a shop vac and do it on the flat. Get 60 feet of string and tie a small puff on one end, put it in one end of the mast and suck the puff out the other end.
My opinion is down the mast
in addition to the other points already made, putting it on the backstay leaves it subject to physical damage. Combine that with the exposure to the elements. A small nick in the outer insulation will allow the cable to absorb water and that can cause corrosion and / or greatly increase line loss and reduce the signal unnecessarily. Putting it inside the mast will help prevent these problems. Cables will vary significantly, too. There is RG-8 and smaller diameter RG-58. The center insulation can be hard (impervious) plastic or a softer foam which has less loss. There are different designs for the shield, too. You might want to do a little research about the cable itself to find the best kind. You may already know but there are two main kinds of cable - 72 ohm for cable TV use ( RG-59) and 52 ohm for communications like ham radios and marine VHF. Take some care to seal the connectors, too. Use some waterproof sealing tape and it will help prevent moisture problems and corrosion and extend the life of the cable. If you put it inside the mast, please do yourself and your neighbors a favor and take steps to keep it from slapping inside the mast. If you do not, you will return to your boat and find the halyards retied in all kinds of ways by your neighbors. It can make a terribly annoying noise when your boat rocks. Someone may think it is a slapping halyard when it is not that at all.
in addition to the other points already made, putting it on the backstay leaves it subject to physical damage. Combine that with the exposure to the elements. A small nick in the outer insulation will allow the cable to absorb water and that can cause corrosion and / or greatly increase line loss and reduce the signal unnecessarily. Putting it inside the mast will help prevent these problems. Cables will vary significantly, too. There is RG-8 and smaller diameter RG-58. The center insulation can be hard (impervious) plastic or a softer foam which has less loss. There are different designs for the shield, too. You might want to do a little research about the cable itself to find the best kind. You may already know but there are two main kinds of cable - 72 ohm for cable TV use ( RG-59) and 52 ohm for communications like ham radios and marine VHF. Take some care to seal the connectors, too. Use some waterproof sealing tape and it will help prevent moisture problems and corrosion and extend the life of the cable. If you put it inside the mast, please do yourself and your neighbors a favor and take steps to keep it from slapping inside the mast. If you do not, you will return to your boat and find the halyards retied in all kinds of ways by your neighbors. It can make a terribly annoying noise when your boat rocks. Someone may think it is a slapping halyard when it is not that at all.
Thanks
for all your answers. It looks as if I will go down the mast. This means pulling out the masthead light wiring (which I just fixed), because this wiring does have styrofoam pieces around it to keep it from slapping (too big to get the VHF cable past). So I need to get that out, and then put it back in with the VHF cable. I guess going down the backstay just wouldn't be a seamanlike job.
for all your answers. It looks as if I will go down the mast. This means pulling out the masthead light wiring (which I just fixed), because this wiring does have styrofoam pieces around it to keep it from slapping (too big to get the VHF cable past). So I need to get that out, and then put it back in with the VHF cable. I guess going down the backstay just wouldn't be a seamanlike job.
In the mast....
Tim R has it pretty much covered as far as the cabling. Another thought though....some masts have a slot inside..don't know about Tanzer... that you can run sail slugs in. This would ensure no slapping at all. I rewired my mast several years ago and made up a harness with all my wiring needs in it. I then put foam pipe insulation over the harness. It's soft so even if it moves...no clanging. Also, I used extra heavy cable ties every 3' or so and left the ends on. This helps center the harness in the mast, and helps prevent movement. Important where you come out of the mast at the top, leave a 3 - 4" drip loop. This will make hooking up to your antenna easier, and will help keep water from trying to follow the wire into the mast. As far as wire size goes, for any run over 50' go to RG8U. It's heavy, but you won't believe the difference it will make in your radio's reception and transmission. I increased my effective range by at least 10 miles. Good luck.
Tim R has it pretty much covered as far as the cabling. Another thought though....some masts have a slot inside..don't know about Tanzer... that you can run sail slugs in. This would ensure no slapping at all. I rewired my mast several years ago and made up a harness with all my wiring needs in it. I then put foam pipe insulation over the harness. It's soft so even if it moves...no clanging. Also, I used extra heavy cable ties every 3' or so and left the ends on. This helps center the harness in the mast, and helps prevent movement. Important where you come out of the mast at the top, leave a 3 - 4" drip loop. This will make hooking up to your antenna easier, and will help keep water from trying to follow the wire into the mast. As far as wire size goes, for any run over 50' go to RG8U. It's heavy, but you won't believe the difference it will make in your radio's reception and transmission. I increased my effective range by at least 10 miles. Good luck.
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