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Sandero · 15-01-2016, 17:13

It's not practical to have an uninterrupted cable from the top of the mast to the radio. I have to have male to female connected at the base of the deck stepped mast inside at the ceiling... in a concealed panel... where all the other mast wires are spliced. I intend to use LMR 400 cable and a high gain antenna... new stainless steel whip from Vesper.. all being replaced this spring when the stick comes down. Spray all connections with deOxit.

I'll buy a made up cable.. cut it and add a make and female connectors for the splice.

The Smokester · 15-01-2016, 18:02

Quote:

Originally Posted by Sandero

It's not practical to have an uninterrupted cable from the top of the mast to the radio. I have to have male to female connected at the base of the deck stepped mast inside at the ceiling... in a concealed panel...

Probably should read "...not always practical..." since my cable does run from the decked-stepped masthead to the radio with no other connections or splices. Obviously, this is not always possible.

In my case it took a lot of advanced planning, and some grease, to make it happen. I re-did all my mast electrical so I could choose the order in which to feed each cable and connector through the small hole in the deck and compression post underneath the mast. RG-213 is large and stiff so it would not go through the deck with other cables already in place. It needed to go through first. Then managed to get the radar with its Ethernet connector through towing the wind sensor. With the mast down it was just possible.

**Dockhead** · 16-01-2016, 04:08

Quote:

Originally Posted by leftbrainstuff

Keep them seperate. One antenna to solve all problems is always a compromise.

Those stainless whips are simple and reliable.

If it aint broke do you need to fix it?

I'd focus more on making sure the coax and connectors are in good shape.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

Note the date ofvthe post you are responding to

All that's long gone.

Sent from my SGP521 using Cruisers Sailing Forum mobile app

**Dockhead** · 16-01-2016, 04:11

Quote:

Originally Posted by The Smokester

Probably should read "...not always practical..." since my cable does run from the decked-stepped masthead to the radio with no other connections or splices. Obviously, this is not always possible.

In my case it took a lot of advanced planning, and some grease, to make it happen. I re-did all my mast electrical so I could choose the order in which to feed each cable and connector through the small hole in the deck and compression post underneath the mast. RG-213 is large and stiff so it would not go through the deck with other cables already in place. It needed to go through first. Then managed to get the radar with its Ethernet connector through towing the wind sensor. With the mast down it was just possible.

Same here. Works OK if you plan ahead.

Also helps a lot to use RG213/U which is more flexible.

Rather than grease, I find talcum powder works well to lubricate the pull.

Sent from my SGP521 using Cruisers Sailing Forum mobile app

The Smokester · 16-01-2016, 08:37

Quote:

Originally Posted by Dockhead

Note the date ofvthe post you are responding to

...

Oops. Duh. Just saw you respond on another thread with similar topic about the continuous cable run and...Fast worker, I thought. .

Thanks for the tip on the talcum powder...Grease is messy.

Sailmonkey · 22-01-2016, 06:14

Quote:

Originally Posted by The Smokester

Oops. Duh. Just saw you respond on another thread with similar topic about the continuous cable run and...Fast worker, I thought. .

Thanks for the tip on the talcum powder...Grease is messy.

I'm a fan of dishsoap myself, the cheap stuff that dissolves easily. Make your pulls, then run a hose through the mast......added bonus is the free internal mast cleaning.

Muckle Flugga · 22-01-2016, 06:34

Quote:

Originally Posted by transmitterdan

Is it a "bad idea"? No, I don't think it's a bad idea. But lots of masts don't have pointy rods. Lightning is basically a random thing and whatever you do only shifts the odds a little bit one way or the other. There are no sure fire ways to prevent damage.

The rod will reduce the signal of your AIS and VHF voice comms at some bearings. By how much is hard to say with certainty. Basically if you feel more comfortable with the rod then install it. Check your VHF range by driving the boat in a slow circle (really slow) and looking at AIS targets. If there is a blind spot at a certain bearing it should be readily visible as AIS targets fail to update. You could also hail some boats at various bearings and ask about your quality of signal. If all bearings allow adequate contact then don't worry too much about it.

Ha ha. Well yes. My static diffuser at the masthead I call my "voodoo stick" because that is roughly the amount of faith I have in it! I have rather more faith in the large copper lattice (80cm Sq.) which I hang off the cap shroud with a big copper wire and alligator clip. Had it made for me by a lightning protection company. Won't stop the strike, but will likely mitigate it. And right now I am in a severe lightning zone. Used at anchor and moored.

Richfind · 28-04-2016, 20:16

I am currently using a Metz Manta 6 on RG 8X "skinny cable" and have been quite happy with the performance. I have a Vesper AIS/VHF splitter connected to allow one antenna to be used for both systems. I currently have the mast down and am planning on replacing the cable with RG 213. Also increasing the size of the mast conduit to accommodate some new goodies.

In walking around the boatyard for good ideas I noticed that over half of the masts had problems with the anchor light/tri-color being obstructed by various other masthead devices.

The worst offender was the base loaded VHF whip antennas. The base of the whip antenna is fairly large. If the antenna is mounted too high the antenna loading coil blocks a very large arc of the light. If the antenna is mounted low enough then only the whip itself is in the light path and does not cause a problem.

Another problem are fiberglass antennas. They have a fairly large diameter and can block a section of the light.

The final item I saw a lot of problems were wind sensors blocking large sections of the light. Windex vanes looked reasonable because the support rod is fairly small in diameter.

**s/v Jedi** · 29-04-2016, 06:05

What helps is to have antennas, wind sensors etc. blocking the 3-color light at exactly where one color of the light changes to another.

The Garbone · 29-04-2016, 06:34

I put a masthead for voice and ais on the spreader. Lightning took the masthead so for now my AIS is disconnected and my spreader is voice. I realm need to go up and replace the masthead.

bobmcd625 · 26-07-2016, 14:47

I am studying this thread carefully, but it's taking me, a newbie to modern marine electronics) a while to absorb it all. What I am particularly interested in, which does not seem to be addressed directly, is what (quality) antenna and cable should I get to use with a (yet to be purchased) fixed mount VHF radio with AIS receiver built in and connected via N2K to a B&G Vulcan 7 display. There will also be an external GPS antenna, so the radio does not have to have GPS capability. My most likely candidate is the B&G V50 (or the Lawrence Link 8 or iCom M506). I do not plan (now) to have an AIS transponder for which I do understand that a separate dedicated antenna would be needed or a splitter. But, for my simple, one VHF set up: Which antenna? Which cable?
Many thanks in advance
Bob

Hartleyg · 26-07-2016, 19:11

Bob,

It depends a bit on what you want out of the antenna - I see you are in SF Bay, so if you want an antenna for "around the bay" communications, you can save a lot of work and hassle by installing an antenna on your aft rail - the installation won't involve threading a cable up the mast, and the performance will be pretty much all over the bay whenever you need it. If you want maximum "out at sea" performance, you will want to install it at the masthead.

For a rail-mount installation, I would recommend RG-8X cable, a rail mount with a 1" thread, and one of the 4-5 foot antennas on the market such as the Shakespeare 396-1 or 6400-R. If the cable run is short enough that the 15 foot (or so) included cable will reach, then RG-58 is OK - any longer, go with the RG-8X size.
For the masthead, I favor RG-213 cable (bigger, heavier and lower loss) because the run is longer, though RG-8X would be the second choice. I would firmly recommend against using any RG-58 cable (too much loss). For the antenna, my preference would be one of the half-wave whips such as the Gam SS-2 or Metz Manta-6. They are fairly easy to mount, and the whip doesn't add a lot of windage. The big issue with mast-mounting is that (unless you already have a pull-string in place) you may have to pull the mast to get the cable into place. At a minimum, someone is going to be spending quite a bit of time up on top working..

73 DE Hartley

bobmcd625 · 26-07-2016, 19:37

Thanks, Hartley. Sounds good. I have a mast head antenna now and want to replace it. I have no idea what it is or how old. I plan to pull the mast anyway for some other tasks, so pulling the new cable won't be hard. I just want to be sure that the new gear can handle AIS, DSC and voice traffic.
Appreciate your advice!
Fair winds.
Bob

Hartleyg · 27-07-2016, 17:16

Glad to help, Bob. The biggest failure point is the connection to the antenna - make sure you have a good seal at the connection. In my experience, masthead antennas do NOT last forever - if you get 10 years, you did really well..

73 DE Hartley