Re: VHF antennas

Mark McGovern


I successfully ran LMR-400-UF (Ultraflexible) down both the Mizzen and the Main for AIS and for VHF so it can be done.  I was actually even able to run a third length of it down the Mizzen mast for a Wilson Omni Directional Cellular in the Mizzen and one in the Main.  However a few big caveats:

1.  I had the masts down on the ground, not stepped on the boat.  This gave me much better access for pulling the cables than you will have with the masts stepped.  I could basically pull the cables out the hole in the bottom of the mast.  See the picture below:

Obviously, with the mast stepped, you don't have this access.  At the base of each mast you only have the small access ports from which to either feed or pull the cables.  And that access is tight.  Real tight.  If you have not done so, remove the cover and see for yourself.  Yes, you can pull the cables straight out the top of the mast with the cables stepped, but having worked at the top of the mast I can say with certainty that it will not be nearly as easy as doing it standing on solid ground.

2.  I removed a bunch of unused cables from the cable chases in the masts before I ran anything.  I removed:

  • TV antenna cable
  • AM/FM antenna cable
  • Furuno Weather Fax cable
  • Radar cable (I replaced this cable but I ran it up the mast last after I ran all the other cables)
This gave me more room in the cable chase and way less cable on cable friction when pulling the fat 10mm OD LMR-400-UF cables trough the chases.

Other things I learned doing this:

  • Don't count on using the pre-run mouse lines that Amel so kindly left inside the mast to pull cables.  Mine were either already broken from UV degradation or broke the first time I tried to use them. I ran new ones using a fish tape on the mizzen and using the TV antenna that I was removing on the main.  When you are done, be kind to yourself or the next owner and re-run new mouse lines.
  • You will need to remove the lines with the sound deadening foam "bowties" before doing anything.  Be prepared to make new ones to replace these as these lines may be broken already or might break when you try to remove them.  It is NOT optional to replace these.  Others have done so and had the cables "clanging" in a rolly anchorage.  If you are not sure what these are, see this post:
  • Use a cable lubricant when pulling the cables.  I used a product called Aqua Gel II Wire Pulling Lubricant from Home Depot. I got a quart for under $20 and still have ~80% of it left.  It is pretty amazing stuff.
  • At the bottom of the mast the cables all have to make a 180 degree turn to go back up and then another 180 degree turn to go back down the "stub" that is in each of the the mast steps where all the cables run down into the boat.  This 360 turn is essentially a drip loop and prevents water running down the cables and into the boat.  Below is a picture of the mast step so you visualize what I am talking about:

You can see these "stubs" by removing the access ports in the side of the masts.

To summarize:

You can install LMR-400-UF cable in Super Maramu Masts, however, I wouldn't try it with the masts up!  

Feel free to ask me any questions.

Mark McGovern
SM #440 Cara
Deale, MD USA

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