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SSB on junks (including antenna location, ground plates...)

  • 03 Mar 2013 05:18
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    Reply # 1231828 on 1230219
    Deleted user

    Just a bit of an update to this thread - last night was the official trial run of my newly installed SSB radio. Spoke to another yacht and also Taupo Maritime which is New Zealand's official government maritime radio station. Both parties reported that Footprints came through with a very strong signal. So it works !

    Of course the antenna is only a part of the installation. Equally important is good radio and tuner, a good battery installation with minimal voltage drop between the battery and radio, and many would say the most important part of the installation is the ground or counterpoise. Lots of different ideas are floating around about the best way to achieve the latter but for me the external underwater bronze ground plate seemed the best, simplest, and guarnteed success solution, especially because I found a very cheap second hand ground plate. All the gear on Footprints is second hand and the radio and tuner have already done a circumnavigation on another yacht.

    Well, that is another major item on the offshore equipment list crossed off, now back to the DIY self steering system.

    Last modified: 04 Mar 2013 04:06 | Deleted user
  • 02 Mar 2013 03:18
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    Reply # 1231235 on 1231142
    Anonymous member
    Daniel Collins wrote:Whoops got David and Kurt backwards there... no thread history to review in the compose window and trying to do three things at once as usual!
    The way I manage this is to have two tabs open with the comment I want to reply to, and then to hit "quote" on just one of them, so that I have the other to refer to.
  • 02 Mar 2013 01:03
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    Reply # 1231184 on 1230219
    Deleted user
    Dan, my call is WA4CHQ and I got my ticket in 1972.  CW is great for low power and when bands are noisy.....
    http://www.qsl.net/wa4chq/radio.html
  • 01 Mar 2013 23:54
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    Reply # 1231142 on 1230219
    Deleted user
    Whoops got David and Kurt backwards there... no thread history to review in the compose window and trying to do three things at once as usual!
  • 01 Mar 2013 23:51
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    Reply # 1231141 on 1230219
    Deleted user
    Wow, I love the ideas here!  Make me think about why I became a ham in the first place - the ingenuity, resourcefulness, and general camaraderie about hacking all things physical to get contact.

    Lesley, I think you've found the perfect line to use with your antenna plans, too - that ski line sounds brilliant.  I remember splicing Dynex Dux (another good but expensive single braid) and I have run antennas inside of it back when I had standing rigging and it worked a treat.  I would definitely keep the wire insulated if at all possible for help reducing corrosion, though I'm sure you'll still get years of service even if you don't.  

    Kurt, maybe you can speak to longevity of uninsulated wire as I think you mentioned yours was bare?

    Neil, David... all great comments.

    Who has what ham call?  I still need to work on my CW... it is truly the way to get a message WAY out there with very little power.

    73 de KI1L
  • 01 Mar 2013 18:45
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    Reply # 1230904 on 1230219
    Deleted user

    I certainly considered just running the wire up by itself because as you say it should be plenty strong enough to support itself. But the idea of running it inside the rope seemed, as Kurt says, a lot more elegant. It also saved the bother of finding the best way to put a loop in the wire top and bottom. I did initially try threading the wire through normal polyester braid but it was too difficult. Then I thought of the ski rope braid with its hollw core and it all became possible. The lenght of 8mm diameter rope cost me only a few dollars and I already had the SS rings so for less than $10 (less cost of wire) I had an antenna system which is a lot more durable and looks a bit better than just a bare bit of wire going to the top of the mast.

    I thought of various through deck conductor ideas such as Kurt as mentioned but in the end though KISS, hence the idea of running the antenna cable directly through the deck to the coupler which is directly below the antenna.

    Last modified: 01 Mar 2013 18:48 | Deleted user
  • 01 Mar 2013 08:35
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    Reply # 1230558 on 1230219
    Deleted user
    I've done the same as what Kurt mentions in his second paragraph.  As a ham and before rigging Sea Elf as a junk, I would haul a wire up using my topping lift, tuning it with a manual antenna tuner.  I used a piece of shock cord at the base as a strain relief.  At the time I was running QRP cw....low power morse code....power was 1 watt and on 40 meters (7mhz) I worked coast to coast.  On the new converted Sea Elf, I've tried 'loading' up my aluminum main mast.  It worked but I would still go with the random wire.  It doesn't have to be straight or perfect.  (when I was a young ham, a buddy of mine used his rain gutter as an antenna and filled several logbooks with contacts around the world) Regarding the 23 ft length, I'm not too sure about that.  I know that on a freq. of 7 mhz you need 33 ft. which is one leg  of a half wave dipole for 40m.   I've also used what they call here in the states a 'collapsable crappie pole'....a telescopic fishing pole.  I think the one I had was 20 feet.  I took 33 ft of wire and wrapped it around the pole using duct tape to hold it in place.  I mounted in on the stern and used coax to feed the wire vertical to my tuner.  At the base of the antenna, I only attached the center conducter of the coax.  The unattached shielded portion acts as a counterpoise.  If you want to go lower then 7mhz you have to use more wire.  Random wire vertical  Again please note that I run low power.  I've run 100 watts with random wires but not with any that I've described above.
    Last modified: 01 Mar 2013 08:55 | Deleted user
  • 01 Mar 2013 07:41
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    Reply # 1230540 on 1230219
    Anonymous member
    I'm thankful for this discussion.

    Our old HF antenna was inside the foremast; the new one will be closer to radio and tuner, in the chimney to starboard of the main mast. 

    My thoughts to date have been to use insulated tinned marine cable of about 20mm^2 or heavier, and I hadn't though to put it into a rope core, but it seems an elegant way, for thin cable at least. I should look up the tension it can take.

    I had planned a shock cord arrangement to soften any snatching loads. I fully expect it to slap the mast loudly, and for that reason had settled in advance for taking it down, illogically, when it's rough. Better maybe  to move my planned base point farther to starboard, risking its looking like a shroud.

    For a conductor through the deck, I haven't drilled the hole yet, but want to embed a bronze rod in epoxy through the 3" deck and drill and tap its ends to attach a cable terminal for the antenna and the tuner. And insulate...

    Hope the the ideas continue to roll in.

    Cheers,
    Kurt
  • 01 Mar 2013 04:29
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    Reply # 1230452 on 1230219
    Deleted user
    David,

    That's probably how I'd do it if I were using the wire-inside-line concept, although of course I don't have the luxury of running it up the mast in the chimney, which is what prompted this thread.  

    But, and I'm just curious here, playing Devil's Advocate, if you're running it up the mast, why insert it into a line anyway?  The wire can hold a very reasonable tension on it's own, certainly in the range of several tens of pounds of force (the amounts are known and well calibrated for various gauges of wire).  You won't pull shroud-level tension, of course, but there's no need for that.  A few pounds beyond the hanging weight of the wire itself will suffice in your case.  
  • 01 Mar 2013 04:23
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    Reply # 1230442 on 1230219
    Deleted user
    Hi Lesley,

    That's true if you are using copper wire alone for the antenna wire.  Ham operators (like myself) often use copper-clad steel wire as the antenna wire - which is self-supporting even at high tension levels (think rigging wire with an extra-conductive layer of copper over it).  It's very durable and low windage as it's about the same size as insulated 10 or 14 gauge wire, and it's insulation is also durable.  Keep adhesive-lined heatshrink on both ends and it shouldn't corrode much at all in a marine environment.

    Here's one of many sources for this stuff: http://www.radioworks.com/cwire.html
    Radioworks.com themselves are a good source for many components - prices are fair and their quality is high.

    I'd caution you on what you run up double-braid.  The polyester will "wick" moisture both ways, and so will trap some against the wire on the inside for longer than it would if the wire were simply exposed.  So make sure you use well insulated tinned copper in that instance.  Otherwise, it is a very good idea for an antenna you want to hoist from time to time but not necessarily make permanent. 

    Still... the question remains where...
       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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