I hate surprises so could someone please tell me...

[Tony E]

Hello all,
Its minus 47 today up here in Saskatchewan, Canada so it seems like a good time to start planning some renovations for my 26X for this year. I am thinking about putting an antenna or two up on top of the mast and maybe some other things but I was wondering that once you get the wiring down to the deck where does it go from there? I have the one set of connectors for the mast light and I am probably going to put in another 4 pin or 9 pin connector in. My question is once you drill a new hole in your deck then what? Is there a double ceiling? It seems like everyone has a VHF radio with an antenna in the their vessel so is it hard to do the wiring? Is there any directions anywhere on how to do this?
Thanks for your help as always!!!

[Tomfoolery]

I don't know how the PO did it, but the VHF and other cables are run through the headliner to the port side, then along the bottom 'lip' of the headliner toward the stern, below the ports. They just kind of stay up in there by sky hooks or unicorn farts. Since they enter near the mast, the fittings are accessible through the opening around the compression post. Unfortunately, those two plastic covers were glued in place, so it takes a little effort to reattach them.

How they snaked them, though, is a mystery. And there isn't much out there as to how to do it, or at least, not that I've found.

[Tony E]

Thanks Tom. I can't tell if you are being serious or pulling my leg on the "unicorn farts" parts. So do you have a set up with a VHF radio and an antenna on the top of the mast? Did you do it yourself or was it there already? I would love to get a FM antenna and a VHF antenna up on top of the mast for better reception but is it worth all that work or not?

[Globalhobo]

Hey Tony,

We just did the same thing on our . Not sure if it's the same kind of setup on a , but we ran VHF wiring from our radio which we mounted next to the campanionway and then ran the cabling back to the area under the deck and mounted a through deck VHF fitting. You have to completely disassemble the wood and pull out the foam between the ceiling and the deck to get in there and work. I can send you some pictures, if you would like. We completely rewired our entire boat and had to take that apart anyway. While we were at it, we mounted an anchor light on the top of the mast and welded a new aluminum Mast cap to put everything neatly on top. Like I said, I can send you some pictures and describe it in more detail if you're interested.

[vizwhiz]

Oh, unicorn farts work great to hold stuff up! I like em so much i keep a spare in a little box right next to the henweigh!

Do an internet search on "Blue Sea Systems Cable Clam". That and other thru-deck fittings are available for the antenna cable connection at the deck. Then you just have to locate the best route to get the wire to your radio.

[Tomfoolery]

Thanks Tom. I can't tell if you are being serious or pulling my leg on the "unicorn farts" parts.

A man who can still move enough to post a message in that kind of cold is not a man you mess with. So yes, AFAIK, nothing is holding those cables behind the headliner from falling out but unicorn farts, which are considerably lighter than air.

So do you have a set up with a VHF radio and an antenna on the top of the mast? Did you do it yourself or was it there already? I would love to get a FM antenna and a VHF antenna up on top of the mast for better reception but is it worth all that work or not?

Yes, mine has a 3dB SS base-loaded whip antenna at the top of the mast. It came with a TV antenna on the front of the mast, above the forestay hound, but I took it off as I don't have TV on the boat. Use zip ties on the antenna coax, leaving the tails on them, to keep the coax from banging around inside the mast. The X has no foam in the mast, so it's easy to drop a cable down the length, but zip ties will keep things nice and quiet in there.

I'm adding an anchor light up there this spring, but will probably just reverse the polarity of the masthead (steaming) light and add a pair of diodes to make that happen. Maybe put the switch right next to the compression post, as it's easy to get to the existing wire there, and it won't clutter my electric panel area that way.

The PO also added a wind instrument to the top of the mast, which I also removed, but that cable ran to the starboard side. Same deal. I'm sure it's a PITA to snake, but you do have those plastic plugs, some of which are large, to give some access while snaking wire. The wires ran where the side-to-side 'ribs' are in the headliner, starting at the compression post (if memory serves), as there's extra room there. They're just tucked up under the bottom edge of the headliner where they run aft.

The factory put in the nav light lamp cord, but the PO ran the antenna coax and the wind instrument cable.

An advantage of having the VHF antenna at the top of the mast is that you can stick a Windex vane directly onto it. Someone just posted a picture of that, in fact. Mine is separate, but when it dies, I'll probably just put a ribbon on each shroud, keeping the top of the mast a little cleaner.

[Highlander]

Thanks Tom. I can't tell if you are being serious or pulling my leg on the "unicorn farts" parts. So do you have a set up with a VHF radio and an antenna on the top of the mast? Did you do it yourself or was it there already? I would love to get a FM antenna and a VHF antenna up on top of the mast for better reception but is it worth all that work or not?

I use "Kilt farts" because they r cheaper

J
PS , the black foam water pipe insulation works great for holding up wiring along the head liner edge

[Tony E]

Unicorn farts and now kilt farts? You guys crack me up! Okay I will try to give it a go with all of your great wisdom and advice So if I was going to install a vhf radio antenna up on top of the mast I am guessing I would need approx. 50 feet of coax? Did anyone else use coax just wiring? Where did you guys buy the cable from? Your radio? etc. Globalhobo I sent you a pm to ask if you would send me those pics and information in an email...thanks for the help! Thanks Tom once again and everyone else!

[Tomfoolery]

I use "Kilt farts" because they r cheaper

And based on experience with the chili in the gazebo at last year's MMOR, plentiful.

Tony - make sure you use RG-58U (standard, -6.5dB/100 ft) or RG-8X (better, -4.7dB/100 ft). Either one is 50 ohm, which is different than other applications, like TV. PL-259 male connector for each end, and you can join two PL-259's together with a PL-258 double-female between them (that's how my deck connection is made). Gold doesn't corrode, so gold plating is probably a good idea, especially in a salt environment.

Length would be 27 ft for the mast (plus a foot or two), and (guessing) about another 15 ft to get to the area aft the galley. So call it 50 ft, and if you get factory ends, you'll have a nice, molded, sealed connector for the top of the mast, and another for the deck area where the coax dives into the deck. You'll have to put your own ends on in two places, of course. There are no-solder connections, but I'd opt for the soldered types, to reduce the risk of corrosion issue. Heat shrink (with internal adhesive), or coax-seal tape, which is NOT electrical tape. This is the stuff the pros use for sealing plugs to coax, and it will seal to itself and be water tight and weather resistant, unlike electrical tape which just comes apart after a short while in the weather.

https://www.amazon.com/Universal-Electr ... B0002ZPINC

And keep the cable as short as you reasonably can. There is signal loss in any coax, and the shorter it is, the less there is.

Another option, by the way, is to use either the 3dB gain 3-foot base loaded whip, or a 4.5dB 4 ft whip, or a 6dB 8 ft whip, mounted to the stern. You lose the distance advantage of height, but you shorten the cable a lot, and you don't have to break the connection to unstep the mast. My boat had one on the stern at one point, based on the skinny cheap coax coming out of a clamshell on the starboard stern coaming that terminates at the radio. They probably had it for cruising the Erie Canal (no mast), as everyone with a trailer boat up here does at some point.

But my preference is for a 3dB base-loaded whip at the top of the mast, for the range (even with cable losses, the signal will still reach the more distant horizon), and because it's cleaner up there. And the 3dB has a wider vertical azimuth pattern compared to the 6dB fiberglass units, so it's more effective when heeled, which is precisely why they make them.

[Tony E]

Okay that sounds great and thanks again for all the advice. That really helps and starts me off in the right direction. Since I am doing the work on top of the mast anyway for a VHF radio what else can one put up there? I was thinking a FM radio antenna also or can you have both a VHF along with a FM antenna all in one? I already replaced the mast light that is half way up the mast last year so that one is good. Any preferred kind of radio to buy or not buy? I like the feature on the new radios where it has GPS and gives you your position. The ones on Amazon up here go for approx $200 so thats not bad. Thanks again for your help

[yukonbob]

Wind indicator or wind speed or both, Sirius/Xm sat radio, anchor light, additional blocks for all manner of things, deck lights, radar, Radar reflector, (just throwing out everything that can go 'up' and not nessecarially on the masthead) bird deterants...

[March]

Tomy E wrote:
Since I am doing the work on top of the mast anyway for a VHF radio what else can one put up there?

I did that mod five years ago, before a trip to the Bahamas. Snaking the antenna wire through the mast with the appropriate metal fish-line wasn't a problem. Didn't add any reinforcing inside twisters (in order to prevent it from banging on the inside) but that wasn't a problem--can't remember any weird noises at night. Snaking it between the linings took longer. The plug is just behind the foot of the mast--removed the black plastic cover, cabin ceiling, and did the connections properly.

I think we gained a couple of mileages of extra coverage, but not more than that. Originally, the antenna was installed on the port side stanchions, aft of the galley and I still use that location for local lake trips. That's plenty. I also have a Tacktick weather vane (wireless) on top of the mast. Sorry, no pics

Maybe somebody will chime in and explain scientifically how much more coverage you gain by mounting the antenna on top.

[Tomfoolery]

Maybe somebody will chime in and explain scientifically how much more coverage you gain by mounting the antenna on top.

Radio range is usually described by the following formula, which takes into account the slight 'bending' of VHF signals over the earth's surface.

d = 1.2246 ∗ √hf where d is distance in nautical miles, and hf is the height above the water to the antenna.

So my X, with its 27 ft mast and 5 ft cabin roof height had an hf value of 33.5 to the center of the 3 ft antenna. That makes a theoretical range of 7.1 nm. Another sailboat with an antenna at the same height would also have the same range, so the two of them could be 14.2 miles apart. Theoretically. And regardless of antenna gain or output wattage (for the most part) because 25W is more than enough to get that far without interference.

An antenna at only 6 ft up would have a theoretical range of 3 nm, so the other boat could communicate at 10.1 nm separation. Unless they're both at 6 ft, in which case it would 6 nm.

In the real world, you may be able to communicate farther, but that is the accepted formula for marine VHF frequencies of around 156-162 MHz.

Oh, and having said that, I usually do just fine with my handheld unit, at reduced wattage. But if I had to broadcast a mayday call, I'd want the full 25W and the antenna as high as it could be, especially in the lake away from shore.

Edit: Here's a quick graphic to illustrate the point. Scale is grossly exaggerated for effect, but it makes it obvious that theoretical radio range grows slowly with antenna height (square root), so height above the water is the variable that governs assuming enough power and reasonable antenna gain (squashing the pattern to a donut so energy isn't wasted transmitting to aircraft). I didn't show the slight diffraction that the equation represents through a slight increase in range, but I think the point is made regardless.