Replacing coax cable in mast

The Garbone · Jun 15, 2015

You could leave the old coax in place and drill a hole and run new. Have the new leave the side of the mast at the base and go thru a new hole in the coach roof.

I myself pulled the mast and expanded and reused the existing hole in the step.

mortyd · Jun 15, 2015

consider buying a handheld vhf and skipping the muss, fuss and expense. how far do you really need to transmit and receive?

Brian D · Jun 16, 2015

This would be a good time to check everything on the top of the mast. Since you are going to replace the coax cable, might as well bring the mast down and do it right. Even if you don't you still need to be at the top of the mast to mate the two cables and re-run the new cable as you pull the old cable out. This is just one of those things that needs to be done unfortunately.

Chief RA · Jun 16, 2015

There is a good chance that your coax is not bad in a 1996 boat. Since it is encased within the mast and in the cabin there should be no sun damage. If there is any slack the end pieces can be cut off and new connectors installed if that is the potential problem area. If no slack and outer black coax insulation is damaged then just recover it with fresh shrink tubing or the like. Electrical tape works but not as cute!
Send me an email if you wish. Chief

The Garbone · Jun 16, 2015

I have 2 handhelds on my boat but to suggest it they are a equivalent alternative to a mast top vhf goes along the line of suggesting an OB is a equivalent to an inboard on our boats. Sure it gets you there but it also suggests a boat on its way to the chop saw.

Don S/V ILLusion · Jun 16, 2015

One clarification may be appropriate and useful here. That being coax inside a mast, while not exposed to UV, can more quickly degrade (compared with being 'outside') because of moisture encased in a mast which doesn't 'breathe' well. Most good quality cable insulation has UV inhibitors as they are designed for outside use,not buried in soil or in a mast.

Chief RA · Jun 16, 2015

Don, I do not believe the moisture will hurt the sheathing of RG59 or any other RG ratings that I know of. We both know moisture better not get inside though as that will be a killer! Chief

hvbaker · Jun 16, 2015

mortyd said:
and, if some are thinking of going to ther bahamas, i suggest a change of boat since the folk who designed and buiilt you boat consider it a coastal cruiser. unless of course, you know of a bahamas coastal course.

Morris - the Catalina 30 mkIII has a CE category rating of A - ocean. Capable of handling winds of in excess of 40 kts and waves in excess of 13 ft. Catalina yachts is ver proud of this rating and has it listed on their web site.

The Garbone · Jun 16, 2015

The logos o baffles me. The OP asks about replacing coax not if a handheld can call a bridge or not. We all know handhelds work.

As for taking a C30 to the Bahamas there are people who know the weather who take jet skis to the Bahamas from Florida. Guess everyone should have a Westsail type boat if they plan to conduct a voyage of over 50 miles. (I would love a Westsail)

Don S/V ILLusion · Jun 16, 2015

Chief RA said:
Don, I do not believe the moisture will hurt the sheathing of RG59 or any other RG ratings that I know of. We both know moisture better not get inside though as that will be a killer! Chief

Water intrusion from condensation is the problem. Some coax is appropriate for in-mast runs, that being coax constructed and designated specifically as 'direct bury'. The jacket on non direct bury designated coax isn't waterproof. Condensation can easily compromise the dielectric characteristics of the core.

That is why all cable companies use either direct bury designated cable or a product called DID which is a db cable preinstalled inside a poly duct.

Construction of generic coax is quite different compared with 'db' cable. The db cable has a poly jacket or equivalent waterproof insulation including waterproof gel applied during mfg between the braid and jacket.

The cost difference is trivial which makes using the generic coax a bad choice on boats.

Chief RA · Jun 16, 2015

OK Don sounds like you know your stuff but I can tell you I was an Electronics Tech on a USN Destroyer and I am aware that RG works for ship applications. Chief

The Garbone · Jun 16, 2015

Chief RA said:
OK Don sounds like you know your stuff but I can tell you I was an Electronics Tech on a USN Destroyer and I am aware that RG works for ship applications. Chief

Old time Navy week, I was an ET2. Shore stations but a lot IV vhf and hf.

I put in lmr400 and protected the bits that were exposed.

Chief RA · Jun 16, 2015

ET1 teaching at ETA school before "jumping ship" and taking Electronic Warrant (Comm & Radar) in the Army. Chief

The Garbone · Jun 19, 2015

I really can not say. Boat did not have a vhf when we got her and our new standard horizon unit and ram mic are sitting in their boxes at the house. Will not be able to get them installed and tested until October when the temps here drop because we just had a baby girl and she can't handle the heat.

Don S/V ILLusion · Jun 19, 2015

gregorybross said:
I currently have RG8 coax. Looking online most info suggests LMR 400 is a higher quality replacement at not much additional cost. Has anyone used this?

Greg

I use only direct bury rated LMR cable for all my transmission lines.
You can look up comparisons showing the relative loss of LMR and generic RG8 so I will only say it is worth the change solely for that reason. Note the dB numbers have NOTHING to do with sound but rather are log scale comparisons in which 1dB equates to significantly greater radiated power at the antenna.

Also, there are a myriad of differing quality RG8 coax from very good to trash. Without knowing which you have, the advantage of switching could be great

Bob S · Jun 21, 2015

I used the LMR 400 and the only problem is its size. It shares the same space as my radar cable and is about the same size. I think of the top of my head they make LMR 250. That isn't quite as good but much better than RG