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Posted: Fri Apr 11, 2008 12:05 pm
by Love MACs
This has all left me a little confused as to the location of the radio. :? If you are not supposed to NOT bend the cable then the radio would have to be mounded on the interior of the boat? I would have thought, and have seen several boats, that the radio is mounted in the cockpit. How do they get around bending the cable?



Allan

Posted: Fri Apr 11, 2008 12:40 pm
by Catigale
You can bend it, you just have to conform to the spec bend radius...see the spec sheet for the coax of choice..

Posted: Sun Apr 13, 2008 10:08 pm
by Bransher
I agree with Catigale.

In a prior life, I used to work as a marine electrician in a Naval Shipyard. I installed miles of coax that snaked throughout the ships. However, it was necessary to follow the specs. for the degree of bend.

Just do not make tight bends and you will be OK.

Posted: Mon Apr 14, 2008 7:32 am
by tangentair
I have run lots of coax video and signal for medical imaging systems and the general rule of thumb we always used was a 6 inch radius would work for everything. That said, I have also seen radii as tight as a dime's radius that worked but the more you crimp the inner insulator the more the signal gets degraded. A 6 inch radius looks like you wrapped it around a basketball.

Re: Mast wiring

Posted: Tue Jan 24, 2017 2:40 pm
by Hugh
OK reviving this thread for 2017:
2012 :macm: and I've purchased a fixed VHF and a Shakespeare 5215CX antennae that comes with 60' of RG8X coax.

Did later :macm: have the "channel" like RussMT found to fish coax or did you have to use the PVC option?
How does one get coax outside the Mast at the base without a severe bend in it?
Is there a gasket I can use to seal where the coax exits the mast?
I'm assuming I can drill though the deck and somehow feed coax back to VHF most likely to be mounted port side under switch panel.
Anyone have pics of the location of where the coax goes through the hull?

Cedar Wind is on Lake of the Woods in ON and I'm in Canmore AB so popping out to the boat is not an option.

Re: Mast wiring

Posted: Tue Jan 24, 2017 3:14 pm
by grady
Hugh wrote:OK reviving this thread for 2017:
2012 :macm: and I've purchased a fixed VHF and a Shakespeare 5215CX antennae that comes with 60' of RG8X coax.

Did later :macm: have the "channel" like RussMT found to fish coax or did you have to use the PVC option?
How does one get coax outside the Mast at the base without a severe bend in it?
Is there a gasket I can use to seal where the coax exits the mast?
I'm assuming I can drill though the deck and somehow feed coax back to VHF most likely to be mounted port side under switch panel.
Anyone have pics of the location of where the coax goes through the hull?

Cedar Wind is on Lake of the Woods in ON and I'm in Canmore AB so popping out to the boat is not an option.
A bend in the coax at the base is not an issue, you just do not want to kink it. Drill a hole in the mast just large enough for the coax to go thru. Chamfer the hole so you do not have any chafe issues. If you are worried about it you can silicone around it, or install a grommet. I would use a deck plug for passing thru the deck.

http://www.defender.com/product3.jsp?pa ... id=2308466

Re: Mast wiring

Posted: Wed Jan 25, 2017 5:01 am
by Sumner
Image

Besides what Grady posted there are deck fittings like above.

More on my 26S mast wiring here...

http://purplesagetradingpost.com/sumner ... de-42.html

Sumner

============================
1300 miles to the Bahamas and back -- 2015

The MacGregor 26-S

The Endeavour 37

Trips to Utah, Wyoming, Idaho, Canada, Florida

Mac-Venture Links

Re: Mast wiring

Posted: Wed Jan 25, 2017 7:24 am
by BOAT
Image

Catigale wrote:You can bend it, you just have to conform to the spec bend radius...see the spec sheet for the coax of choice..
Hey Catigale, I did not know about the bending thing on the radio coax wire :? what happens if I bend it? :? will the radio signals miss the turn and fly out of the cable and fall into the water? I did not know I could not bend the radio wire! :o (NOW you tell me?? :( )

Hey - I REPLACED my 'Old unused 2 prong.' with a 'New 4 prong.' ! I did not leave the old one there like Sumner did, I thought I was supposed to REPLACE the old one! Did I screw up that too???

Re: Mast wiring

Posted: Wed Jan 25, 2017 11:06 am
by Russ
Hugh wrote:How does one get coax outside the Mast at the base without a severe bend in it?
Is there a gasket I can use to seal where the coax exits the mast?
I'm assuming I can drill though the deck and somehow feed coax back to VHF most likely to be mounted port side under switch panel.
Anyone have pics of the location of where the coax goes through the hull?
I used this for the thru deck fitting. Caulk it well. Pull that panel over the mirror to access this space where it comes through.
Image

Here it is connected to coax. Lot's of thru deck stuffs. (Left to right) halyard run aft, Cell Phone extender, 2 wire for anchor/steaming, coax, XM antenna
Image

I used a rubber grommet to protect the coax as it passes through the mast.

RE: Bend in coax. If you want to live in a perfect installation world, here's a good guide including bend radius.
http://www.nmea.org/Assets/nmea%20consu ... e%20lr.pdf

Most of us don't live in a perfect world. I'm sure I have tighter bends than perfect. It still works well.
If I were sailing to Hawaii, maybe I'd be more concerned.

--Russ

Re: Mast wiring

Posted: Wed Jan 25, 2017 3:53 pm
by Sumner
RussMT wrote:.....Most of us don't live in a perfect world. I'm sure I have tighter bends than perfect. It still works well. --Russ
Working my way back from the Bahamas I was over on the north side of Little Abaco and turned the radio on and tried the NOAA weather stations. Low and behold I had good reception with one. I was 125 miles, as the sea gull flies, off the east coast of Florida. The NOAA towers are tall, still I never knew I could pick them up that far away. I wish I would of know that earlier in the trip as I probably would have had weather at some of my other anchorages.

This was with a Standard Horizon GX2100 with AIS and the antenna at the top of the mast,

Sumner

============================
1300 miles to the Bahamas and back -- 2015

The MacGregor 26-S

The Endeavour 37

Trips to Utah, Wyoming, Idaho, Canada, Florida

Mac-Venture Links

Re: Mast wiring

Posted: Wed Jan 25, 2017 3:59 pm
by BOAT
How do I get the antenna on top of the mast? What kind do I buy to put up there? I would like to put an AIS VHF radio in the dinette overhead and run a coax up the mast to an antenna but I don't know what antenna to put up there or how to attach it - (I don't even know what kind of coax wire to buy!) :? I feel pretty stupid.

I would also like to know if the AIS data from the AIS radio can display it's AIS data on a tablet instead of the chartplotter (or more accurately on a tablet AND the chartplotter)

Is that possible? (I use an ipad but I have android tables too).

Ahh, never mind - I guess I will just put everything on the plotter - that's probably the best way to do it anyway.

Re: Mast wiring

Posted: Wed Jan 25, 2017 6:19 pm
by Sumner
BOAT wrote:How do I get the antenna on top of the mast? What kind do I buy to put up there? ....
The answers to those questions are here...

http://purplesagetradingpost.com/sumner ... de-42.html

BOAT wrote:....I would also like to know if the AIS data from the AIS radio can display it's AIS data on a tablet instead of the chartplotter (or more accurately on a tablet AND the chartplotter)

Is that possible? (I use an ipad but I have android tables too)....
I use OpenCPN (FREE) on a computer and also have it connected to the radio and see the AIS targets on the screen. What I used on the Bahama trip. I see that they also have OpenCPN now for Apple and Android devices. Not sure if you can see AIS with them. I have the computer connected to the radio with a serial cable and also have a GPS USB puck connected to the computer for current location. I assume an Apple tablet or Android would also have to have GPS built in, not sure how it would get the AIS from the radio.

I bought a 7 inch Standard Horizon Chartplotter but will still use OpenCPN on the computer as a backup and will plan trips with it and transfer waypoints to the Standard Horizon with a serial cable that will be connected at all times. I like the big screen using OpenCPN and how fast and easy it is to plan a route,

Sumner

============================
1300 miles to the Bahamas and back -- 2015

The MacGregor 26-S

The Endeavour 37

Trips to Utah, Wyoming, Idaho, Canada, Florida

Mac-Venture Links

Re: Mast wiring

Posted: Wed Jan 25, 2017 7:27 pm
by Tomfoolery
You need a 3dB base-loaded antenna with stainless whip, like this one. https://www.westmarine.com/buy/shakespe ... ecordNum=6 or this one https://www.westmarine.com/buy/shakespe ... cordNum=10 .

Mine is mounted to the side of the mast with a ratchet mount, which allows it to be folded easily (for winter tarping, for instance), like this. https://www.westmarine.com/buy/west-mar ... ecordNum=8

About 50 ft of RG-58U. Or the lower loss RG-8x. Or even better, the much fatter but much lower signal loss of RG-213. Coax must be 50 ohm (TV uses 75 ohm, so that's no good). https://www.westmarine.com/WestAdvisor/Coaxial-Cable

Use solder type PL259 connectors, preferably with gold plating (doesn't corrode). Or get a 50 ft length with sealed factory terminations, and after cutting for the deck joint, put the two sealed connectors in the weather. But you'll still have to do two more connectors yourself, of course.

Re: Mast wiring

Posted: Thu Jan 26, 2017 11:26 am
by Hugh
BOAT wrote:How do I get the antenna on top of the mast? What kind do I buy to put up there? I would like to put an AIS VHF radio in the dinette overhead and run a coax up the mast to an antenna but I don't know what antenna to put up there or how to attach it - (I don't even know what kind of coax wire to buy!) :? ..
I'm in the same boat literally /figuratively. I found a series of videos on VHF installation etc from West Marine.
If you search around they talk about why 3DB is best for sailboats, what size coax etc.
Most of this stuff has been answered here but every little bit counts.
I'm pretty sure Shakespeare makes an AIS/VHF antennae design for lightweight mast installation.
https://www.westmarine.com/WestAdvisor/ ... HF-Antenna

Thanks to everyone here for the extra info. I've got a bit of work ahead of me.
Hugh

Re: Mast wiring

Posted: Thu Jan 26, 2017 11:36 am
by BOAT
I have a beautiful Shakespear mounted on the aft by the factory that works great so it's something I have never thought about but with a thought to add another radio with AIS in it I was going to add another antenna because you can't run two radios at the same time on the same antenna (I'm told once you press the key on the mike of one radio it will blow the finals on the other) thus - if I'm going to add an antenna I figured on a mast top.

With all that jazz I'm getting here about my radio signals falling out of the wire because it's bent too sharp or wrong wire and "base loading" and fabricating antenna mounts (I can't even weld!) it's scaring me so I'm thinking of just replacing my existing radio and giving up on the idea of having two radios.

I dunno - maybe if I get smarter I will not be so afraid and change my mind.