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Old 05-03-2012, 14:35   #1
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Antenna mounts near mast cap

Well I must not be defining my search request correctly because I am not coming up with anything like what I am looking for with a google search. Also checked Defender and West Marine catalogs, nada.

What I am looking for is an antenna mounting bracket that I can screw into the top of my mast near the cap that would be about 12 inches long that I could then mount a VHF marine antenna on one side of the mast and a 2M ham antenna on the other side. This would free up the top of my cap area for tricolor and wind transducer, etc.

Of course I could have these mounts made by a local SS fab house but thought someone may know of a company that make such a mount already.

Thanks for any pointers or ideas.

Don
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Old 05-03-2012, 14:44   #2
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Re: Antenna mounts near mast cap

Aqua signal makes a stainless bracket that is made for mounting an anchor lite or a tri-color up at the masthead. It attaches to the mast near the top, and than has a right angle piece that serves as the base. You can drill this base to make it fit whatever you want to mount on it--ie antenna, light, etc. Relatively inexpensive if I recall.

Good luck!
Gradyrod
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Old 05-03-2012, 14:47   #3
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Re: Antenna mounts near mast cap

How about a simple piece of flat bar ( 2" W x 12" L) drilled in centre for mounting bolts, and bear ends for antennae mounts.
Aluminum (or S/S) stock @ about 1/4" - 3/8" thick might suffice.
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Old 05-03-2012, 14:52   #4
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Quote:
Originally Posted by GordMay
How about a simple piece of flat bar ( 2" W x 12" L) drilled in centre for mounting bolts, and bear ends for antennae mounts.
Hmmmm that sounds workable. If I am understanding correctly. Would you bend the flat bar at a 90 deg angle to mount it flat against the side of the mast? Making the mast end about 4 inches long to give good surface mounting area to place screws tapped into the mast?

Don
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Old 05-03-2012, 14:54   #5
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Quote:
Originally Posted by Gradyrod
Aqua signal makes a stainless bracket that is made for mounting an anchor lite or a tri-color up at the masthead. It attaches to the mast near the top, and than has a right angle piece that serves as the base. You can drill this base to make it fit whatever you want to mount on it--ie antenna, light, etc. Relatively inexpensive if I recall.

Good luck!
Gradyrod
I'll go check out what they have to see if I could make one work.
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Old 05-03-2012, 15:03   #6
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Re: Antenna mounts near mast cap

It's not generally a good idea to mount two active VHF antennas so close to one another, particularly as the 2-meter band is so close to the VHF marine band.

In many instances, a single antenna can be used for both, with a coax switch near the radios. That's the way I've done it for many years. And, I have slightly better SWR on the ham bands than on the marine bands :-)

Alternatively, you could mount the 2-meter antenna lower, say, atop one of the spreaders.

Bill
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Old 05-03-2012, 15:07   #7
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Re: Antenna mounts near mast cap

Agree with Bill! why not use the VHF antenna for both marine and ham? A simple coax switch will allow using both radios on the one antenna. Be sure and run some good coax, like LMR400 , from the radio to the antenna! also, wire the coax with a drip loop and use coax seal to prevent any water from getting to your connection.

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Old 05-03-2012, 15:12   #8
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Re: Antenna mounts near mast cap

Quote:
Originally Posted by btrayfors View Post
It's not generally a good idea to mount two active VHF antennas so close to one another, particularly as the 2-meter band is so close to the VHF marine band.

In many instances, a single antenna can be used for both, with a coax switch near the radios. That's the way I've done it for many years. And, I have slightly better SWR on the ham bands than on the marine bands :-)

Alternatively, you could mount the 2-meter antenna lower, say, atop one of the spreaders.

Bill
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Yes Bill, would completely agree. Was actually thinking of staggering their mount points just for the reason you mention. Intermod. Just getting my thinking cap on around antennas since the mast is down and I want to have everything the way I like before it get re-installed into the boat.

Thanks for the ideas,

Don
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Old 05-03-2012, 15:14   #9
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Re: Antenna mounts near mast cap

I made something similar for the tri colour and a vhf antenna out of 2" x 1/4" aluminium flat bar. I just pop riveted it to the top of the mast which was reasonably flat. If you needed additional reinforcement, you could make bracing struts out of, say, 1" x 1/8" flat quite easily. I preferred aluminium because it is very easy to work, and the risk of electrolysis is reduced somewhat.
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Old 05-03-2012, 15:14   #10
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Re: Antenna mounts near mast cap

Here is a very rough dwg of my mount ideas.

Don
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Old 05-03-2012, 15:16   #11
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Re: Antenna mounts near mast cap

Quote:
Originally Posted by Reefmagnet View Post
I made something similar for the tri colour and a vhf antenna out of 2" x 1/4" aluminium flat bar. I just pop riveted it to the top of the mast which was reasonably flat. If you needed additional reinforcement, you could make bracing struts out of, say, 1" x 1/8" flat quite easily. I preferred aluminium because it is very easy to work, and the risk of electrolysis is reduced somewhat.

Good point, initially was thinking SS for strength but a solid piece of Alum would work just as well and would reduce the electrolysis

Don
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Old 05-03-2012, 15:20   #12
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Re: Antenna mounts near mast cap

Quote:
Originally Posted by Gradyrod View Post
Agree with Bill! why not use the VHF antenna for both marine and ham? A simple coax switch will allow using both radios on the one antenna. Be sure and run some good coax, like LMR400 , from the radio to the antenna! also, wire the coax with a drip loop and use coax seal to prevent any water from getting to your connection.

Gradyrod
I think you and Bill have me re-thinking what I was going to do. Have a couple of coax switches in the hamroom not being used anyway.

Plan to build an inverted V to raise at anchor whenever I want to get onto HF. Probably run it up that spinnaker halyard since I don't fly a spinnaker anyway.

Don
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Old 05-03-2012, 15:47   #13
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Re: Antenna mounts near mast cap

Quote:
Originally Posted by Gradyrod View Post
Agree with Bill! ...
Always agree /w Bill, in these matters.
I was just imagining a straight horizontal bar, mounted flat to the top of the mast, per Reefmagnet.

Don:
Why is your screen name Dan, whilst your signature Don? Please don't add unneeded confusion to an already confused old man.
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Old 05-03-2012, 16:23   #14
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Re: Antenna mounts near mast cap

Don,

For HF, you might consider a full-time solution, like an "alternate backstay" antenna which is easy and inexpensive to build, very robust in the marine environment, and which functions as well or better than a traditional backstay antenna.

Just use a length of insulated 3/16" s/s lifeline, more than 23' in length, and string it up on a spare halyard. Tie the lower end to the pushpit on one side, feed it from a tuner underdeck with GTO-15. With an appropriate counterpoise (like the KISS-SSB radial system, your own radial system, or other) it will tune all bands, marine and amateur and will work very well. Here's one way to make the GTO-15 to antenna connection:
http://wdsg.com/gallery/main.php?g2_...geViewsIndex=1

Inverted V's are OK insofar as they go, but they are not really seagoing antennas ("rig them at anchor") and they have a high vertical angle of radiation....not at all good for DX, but fine for relatively close contacts.

If you really want an honest-to-god killer single-band HF antenna, think about a vertical dipole. I make them from s/s lifeline, too, and you can't beat them for DX on 20 meters and above. Construction details for a real marinized one -- able to withstand hurricane-force winds -- are given on my website here: Marine Antennas

Bill
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Old 05-03-2012, 19:13   #15
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Quote:
Originally Posted by GordMay
Always agree /w Bill, in these matters.
I was just imagining a straight horizontal bar, mounted flat to the top of the mast, per Reefmagnet.

Don:
Why is your screen name Dan, whilst your signature Don? Please don't add unneeded confusion to an already confused old man.
LOL Gord...... My name is Don Andrews, I use a screen name of dandrews often because there are too many Don's in the world. Not sure where you are seeing Dan.

Don
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