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SVPenguin

Solder or Crimp? (was: Paper or Plastic?)

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There are a few debates out on the interwebs about this and I thought I'd spark one (sorry) on the Panbo forum think-tank.

I have in mind specifically coax connections and have scoured the the resources. I am refitting a couple of VHF antennas, and a new AIS transponder so my decision is to bite the bullet and buy a high quality crimping handle and the appropriate fittings for my cable.

Ours is a sailboat and one of the VHF antenna's is at the 65ft mast. The other (the AIS) will be mounted pointing down on the outboard end of one of the spreaders to get vertical separation. Because of the distances involved, I've decided to go with tinned RG-213, which is evidently more difficult to manouver but has much better loss characteristics over distances.

Does this seem a good approach?

-Matt

2 Replies

  • I was just pondering this a couple of weeks ago.

    I found it easy enough to use a screw on product that requires a single bit of soldering from Shakespeare, that comes with their sailboat antenna (watch for it on Panbo in the future)

    However, when I went to look for the equivalent for some LMR-400 and RG-213 couldn't find the equivalent. Instead, I encountered all this advice on the internet that involved over a hundred dollars in tools for crimping.

    I bet it's real easy and takes minutes, but for a first timer it takes a while. Kind of like upgrading the coax in my home, the first couple took some trial and error, and then I was popping them off like a professional.

    For these thicker cables I decided it's better to have someone make the cable for me.

    http://www.air802.com/pre-made-cables-antenna-cable-assembly/

    I ordered last week, they shipped the same day I ordered. (They had a pre-made length that worked good for me)

    I plan to remove all the cables in the mast conduit so I can slide this baby in connector and all, but if that doesn't work, I can have an end removed then added by a local installer for a fraction of the effort and cost of learning how to do this myself for a size connector I won't need to deal with again for years.

  • I bit the bullet and ordered the plugs and the crimping tool from oddcables.com. (They've got a great FAQ that decodes all the jargon). http://www.oddcables.com/glossary.asp
    (I have no affiliation with them other than as a customer)

    The tool with one die for plugs that fit the cable I'm using (RG-213) was $62. The plugs run three and a half bucks a piece. All in I've got enough the tool, plugs (and some spares gor when I mess up)for right on $200. That's to do 3 antennas. Could I get someone else to do it? Yeah, but I've had big problems with "technicians" so I'm gonna do it myself.

    Coaxial cable comes in more flavors than ice cream.

    VHF requires 50 ohm cable not 75 ohm cable (that�s for TV signals).

    Marine VHF applications require 50 ohm coax. TV cable is 75 ohm and is not suitable. (Who knew?)

    Suitable cables include RG-58 which is only suitable for connecting equipment (jump cords), RG-8X works fine runs up to about 65 feet, RG-8U and RG-213 are the same size, RG-213 has more waterproof and UV resistant insulation.
    RG-213 is more difficult to work with when it comes to making connections and is more expensive,
    RG-8U is recommended by IOC and ISAF for offshore race requirement to power an antenna feeder cable with less than 40% loss(!)

    Cable should be marine grade: Coax with copper braid, tinned copper braid. Solid wire gets work hardened from vibration and flexing and cracks. Un-tinned copper corrodes with salt water intrusions.
    (Beware that all types come in tinned and un-tinned, experience speaking)

    Core should be solid polyethylene. Foam core sucks moisture into the cable and causes the core and braid to corrode.

    The quality of your cable, connections and antenna are the keys to powerful, consistent, dependable, communications. I know I want to put the effort and expense in, so that when I really need to communicate, I can.

    Connections:

    Soldering coax is a highly skilled craft not for the newbie, bad connections come from cold joints and even heating the materials too hot can change their electrical resistance permanently.
    http://www.oddcables.com/faqs_crimp_solder.asp

    The US Air Force evidently uses crimped connections exclusively. They find they hold up under vibration better.

    Heat shrink tubing over all connections AND self amalgamating �rescue� tape to water proof them.

    Sources:

    http://www.bcdxc.org/pl259_crimp_on_connectors.htm

    http://www.saltyjohn.co.uk/resources/Marine%20VHF%20Antennas%20(aerials)%20and%20their%20installation.pdf