Routing cables through the antenna mast

[HeadedToTexas]

In addition to anchor and running lights, our mast has two GPS antennas and an old radar antenna. One of the GPS antennas is decommissioned and I am replacing it with a SeaWatch antenna to access local over the air TV signals.

Coax cables for the GPS antennas passes out of the mast and into the wings in a channel that is apparently drilled in the wing to the point where it intersects the 1"-14 threaded mount. My plan is to use the old 1" mount to route the cable as the SeaWatch has a coax connection separate from the 1" mount as shown on the photo of its underside.

Is there a gland seal that fits standard male 1-14 threads common to these antenna mounts? Do three mounting holes on ScanStrut seals like the DS21 fit the same 3 holes as the 1" mount? What is the best approach for sealing the point where the cable leaves the wing?

 

[HeadedToTexas]

Okay, let me try this another way. My radar mast wing has a standard 1" antenna mount. I would love to find a cable gland seal like the one below with 1-14 female threads, but that doesn't seem to exist. Threaded coupling adapters from the 1-14 threads on the mount to common sizes in the gland seal world like 1" NPT are also nonexistent. There must be a better way...

 

[DrissZougari]

you should move the SS old GPS base to use for the Antenna, a blank SS plate (or other material easy to work with) with same screws configuration as the base with a center hole for a cable gland seal for the cable (easy to find).
PS: make sure you use 5200/4200 to seal the blank plate accordingly.
Good luck.

 

[Comodave]

I used to use 5200/4200 but in the last few years I have gone to Sika 291 for general caulking. I like it much better. I had a run of bad tubes of 4200. Still use 5200 for absolutely permanent things below the waterline.

 

[O C Diver]

Think I would get a piece of 1/4" white Starboard and use the old GPS mount as a template for the base and then use the pictured cable gland in the center. Starboard is easy to work with and pieces can generally be found on Ebay.

Ted

 

[HeadedToTexas]

Great ideas. Thanks guys.

 

[HeadedToTexas]

Well that did not go as planned. The first problem was that the GPS antenna cable was a six conductor small gauge cable instead of coax. That meant that the coax for the SeaWatch could not be pulled through the same turns and small drilled channels in the mast wing that the thin, flexible GPS cable followed. And that meant that the elegant starboard plate I made to secure the cable seal would not work.

Instead, I passed the coax through the same rather half assed clam shell fitting that covers the radar cable where it leaves the mast. The rest was pretty simple. It's temporary, but it got the job done in time to watch an excellent Ohio State game. Yes, I'm a Buckeye.

So my question now is how to access the inside of the radar mast, and is that even worth the effort? Heavy rain or spray has apparently entered the mast for years through that clam shell cover and never made it down to the salon. The folding mast mount is designed to drain water out of the bottom of the mount before it overflows through cable raceway into the cabin below. The mast is like 9 feet tall and without removing the mysteriously sealed cap, is only accessible from the bottom at the hinged mount. My arms are not that long!

The clam shell cover is simply attached with screws into the fiberglass mast with no backing wood, plate, or nuts. I suppose I could mount a Scanstrut type cable seal (left) the same way, but I would prefer to use an Ancor type seal (right) with the nut to secure it on the inside.

 

[SIBERNUT]

Getting ready to do radar. When your cable comes out of the mast , where is it routed after that ? Have not removed the mast yet, you mention. " cable raceway". Can I hope there is one under mine ?

 

[O C Diver]

There appears to be an "L" bracket that holds the wing in place. I can't tell if they are sheet metal screws, nuts on the inside of the mast, or longer screws that go through the mast and hold the bracket on the other side with nuts on the outside.

In an easy world, I would either remove the "L" bracket and mount the cable gland in the bracket after drilling an access hole in the mast, or mount the cable gland through the mast below the bracket and access the nut by drilling a hole that would be covered by the bracket.

Ted

 

[HeadedToTexas]

Getting ready to do radar. When your cable comes out of the mast , where is it routed after that ? Have not removed the mast yet, you mention. " cable raceway". Can I hope there is one under mine ?

The radar cable runs forward to the chase leading to the upper helm. Our radar was an afterthought.

 

[HeadedToTexas]

There appears to be an "L" bracket that holds the wing in place. I can't tell if they are sheet metal screws, nuts on the inside of the mast, or longer screws that go through the mast and hold the bracket on the other side with nuts on the outside.

In an easy world, I would either remove the "L" bracket and mount the cable gland in the bracket after drilling an access hole in the mast, or mount the cable gland through the mast below the bracket and access the nut by drilling a hole that would be covered by the bracket.

Ted

Great idea, Ted. I'll back one of the screws out enough to see the threads. That should indicate whether or not there are nuts on the inside. Might even be able to see the inside of those fasteners up from the bottom.

Mariner/Helmsman has a habit of using screws to hold hardware (and mirrors) in place while the adhesive cures. Taking the screws out may only be part of the battle. That said, the 1" antenna mount came off with little effort. Perhaps those L brackets will too. More as I know it. Thank you!

 

[SIBERNUT]

The radar cable runs forward to the chase leading to the upper helm. Our radar was an afterthought.

When you say "chase", is there a conduit in your bridge deck to the upper helm? My mast wires (3) have a plug that goes into a socket on the deck.

 

[HeadedToTexas]

Hmmm, my boat is hull #3 and back in 2007 Mariner just provided holes through the bridge deck structure that made hiding wires above the salon headliner panels neat and easy. Pros and cons, I suppose. We have a continuous many conductor cable running from the radar unit on the upper helm through the console, through the floor, up the mast, and out to the radar antenna.

 

[SIBERNUT]

Tks. My Khoudung 30 has no such convenience. Very nice.