[CQ-Contest] Need Hardline Connectors

K4SB hamcat at directvinternet.com
Thu Aug 29 18:20:19 EDT 2002


Bill wrote:
> Hi Contesters,
> Can you help me find a source of connectors for surplus
> hardline? Today's problem is with aluminum, approx 1/2"
> hardline with a solid conductor. Exact dimensions on
> request.
Bill K6KM

Well, the cheapest and most effective method I've ever found is to
make them yourself.

Cut about a 6" length of the 1/2" hard line, and visit your local
hardware store. Also,
take along a barrel connector.

You will find they have brass compression fittings which will allow
the fitting to be
securely mounted to the hard line, along with a "step up" on the other
end which is almost a perfect match for the barrel.

Just place the compression ring on the hard line, ( be sure you put
the compressor fitting on first ), then bare the center wire so it
will be about .75" into the brass fitting. You can now either file off
the threads on the barrel connector, (or drill out the brass fitting
with a 1/2" drill down to the point where the inner housing begins to
expand ) and you will find  perfect fit. A little no-alox on the
center wire, and fit the barrel down into the unit. You can now make a
very neat solder around the barrel fitting. A little more no-alox on
the aluminum shield, especially under the position where the
compression ring will come to rest, and tighten it down.

Helps if you have a dremal tool with a circular carbide blade to cut
through the aluminum to expose the center conductor, then slit the
aluminum from the cut to the coax end. Remove the outer shield and
then slice away the insulation back about .75" from the end. Gasoline
works great on a rag to remove that sticky stuff.

It has literally taken longer to write this than to make the actual
fitting.

As to performance, I tested several connectors up to about 200 mHz for
loss and found it was practically non existent. When I first started
using this method, I made up 2 short connects, put coax seal and tape
on one, and hung them with the coax end up on a fence for a little
more than a year. Then, took them apart, and honestly could not find
any difference in the appearance of the 2.

Short and sweet, Ace is the place for the ....

73
Ed



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