Mast Head VHF antenna installation

[brackish]

I'm about to do this installation, would appreciate any advice.

The Mast head light and deck light connection comes out on deck just to the starboard of the mast and directly above the starboard cabin bulkhead with a multi pin disconnect and weather cap.   According to Hutchins, you can access the feed used for the lights by removing the trim piece from the starboard bulkhead.  I'm assuming they mean the short top horizontal trim pieces which will show the feed through one of the vertical trim pieces.  I'm led to believe that I can take the VHF coax through the same cavity.

Anyone done this and wish to share their experience.  Also, what did you use at the penetration through the cabin trunk roof.  Weatherproof gland with a loose connector?  Long connector with weather cap?

Thanks

Frank

[edbuchanan]

Hi Brackish,

The wires for the mast and cabin lights lie inside the vertical trim piece, at least in my boat.  The trim is under some force, so you may have to relieve pressure from the mast by loosening the turnbuckles a bit.  I used a router to carve a channel in the vertical trim to allow space for the coaxial cable, anchor light, steaming light, and cabin light wires.  They all fit!  RG/8x coaxial cable was chosen over RG\58 since it significantly reduces signal loss.

The deck penetration I used was the existing steaming light connector hole.  I made a small teak block with a pair of connectors mounted on it, one connector for the antenna, the other for the lights.  The block allowed a covered channel for the wires on deck to the second connector.  A Perko 2 pin deck connector body was used for the coax by boring the inside diameter to accept a short female/female UHF adapter.  Space is very tight, so I'm not sure if I would recommend the method I chose.  At least the installation has a very neat appearance.  Some sort of deck-gland might be much easier.

The masthead antenna makes a huge difference in radio range.

Ernie, Molly 23/II (1984)
 

[brackish]

Thanks, I expect mine is routed the same way.  No problem with the mast pressure, it is currently down and off having things done to it.  Your plan or some slight variation, sounds good.

Looks like the attachment method for that vertical trim piece was maybe panhead screws in counterbores with teak plugs covering.  At least the plugs are the only thing visible.  Is that what you found? 

I was concerned with the RG/8X because of the slightly larger diameter.  Good to know it will fit.

Frank

[edbuchanan]

Hi Frank,


My boat does not have plugs over the screws, so yours might be different.  Can you see wires hiding under the wood?  There is a small gap viewable from the forecastle, you might just be able to see them.

Yes, the RG/8x fit, but it was quite a job.

Ernie (Molly 23/II, 1984)

[Craig Weis]

VHF and anchor light...the steaming light is already factory there.
With my Com-Pac 19 mast laying on garbage cans in my backyard, I guess-a-mated where to drill the coaxial cable hole exiting at the base of the mast. IT MUST BE ABOVE THE TOP-O-TABENACKLE and in the fwd section of the mast's seam as this part of the mast provide a clean shot to the top-o-mast. Then I pulled the fasteners holding the cast aluminum masthead and pulleys at the top-o-mast. Ahhhh Haaa!! A tunnel. No big deal I fished some electric bell wire clean through the mast top to bottom. Drilled my holes and pulled the radio and anchor wiring with this 'fish' bell wire. With both wires sticking out of each end of the mast I maneuvered both wires through both holes and left plenty of extra for later. I selected where the 'through the cabin roof' holes where to be drilled from inside the boat. Not outside. I put the radio and the anchor fittings side by side, taped the glass [my boat is an XL] insert and drilled a pilot hole. CHECK CHECK CHECK, walk through the whole job before you drill. I used the longest female/female solder connection Shakesphere had and had just enough sticking out of the cabin roof thickness and inside for the cable to be fitted. I ran all the lines on the fwd side of the compression post and down past the inspection plate, pass through the vee birth storage and out under the quarter birth cushions, one to the switch panel area and one up between the two fiberglass bulkheads adjacent from the dropboard.
I think I have a masthead picture in my Frappr link below.
I drilled and used selftapping sheetmetal screws to lay in the bracket for the antenna and the light. The Davis Anchor Light has a switch controlling power to it so the light will not come on at the dock at night. Fused power to the electric eye only when I need it.
Use copious amounts of 3-M 5200 slow set with anything going through the roof. And rubber grommets around the drilled holes for the wiring. Won't matter if the mast is water tight.
skip.

[brackish]

As an update I found the wire chase.  On this particular boat the chase is not in the trim, but in the middle of the bulkhead.  Looks like the factory routed a slot on the forward side of the bulkhead plywood then covered that whole side with a piece of white HPL, so teak showing in the main cabin, white HPL forward.

Found it by removing the cabin lights and the top horizontal trim pieces from the starboard bulkhead.  The good news is that I got a wire fish down the slot to the exit hole below the forward starboard bunk and should be able to get a run of RG-8X through without a problem.  So should be a nice neat installation with no wires showing, somewhat easier than I thought. 

It does exit the cabin center of the vertical trim, and looks like there is enough room next  to the four pin connector on the cabin trunk for an additional gland for the VHF.

Now converting my windex to mount on the antenna.

Frank