Topband: Using old 1/2 inch Comscope hardline for my 4-square

[Dick Bingham]

Greetings All

Where Terry Burge posted ===>
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Message: 1
Date: Mon, 25 Jun 2018 22:07:47 -0700 (PDT)
From: terry burge <ki7m at comcast.net>
To: topband at contesting.com, terry burge <ki7m at comcast.net>
Subject: Topband: Using old 1/2 inch Comscope hardline for my 4-square

Hi guys and gals,

W9XT came up with a way to connect a PL-259 to a 1/2" hardline. Since I
find the Comscope 1/2" hardline I got a whole 4' spool of is not even
listed by comscope or any of the manufacturers of hardline I have to try
and make a connector. Using his method the toughest part is to 'shrink' the
copper clad aluminum or steel center lead. I don't think I can do it. So
I'm thinking about using his method modified with 14 gauge wire thru the
center conductor of the PL-259 and wrap it around the center conductor on
the hardline. Then solder that in. Then use the brass tubing the way W9XT
does and solder to the outside of the PL-259 and clamp on the aluminum
outside of the hardline shield. THEN try using something like 'liquid Nail'
squirted into the inside thru a small hole drilled in the brass tubing to
act as insulation and give it some strength. Strength is the biggest
problem for using the hardline I think and maybe running up my tower. I
don't think it will be strong enough without something like the liquid nail
and I plan to use a couple of long sections of heat shrink to help. Being
in Oregon keeping water out of the connections can be a challenge. But
drilling out that center conductor I don't think will work for me.

Liquid nail should harden up and I doubt it will have a problem with
shorting out the hardline or PL-259. Time may tell another story of course.
Various 2 part glues like Loctite or Gorilla glue I don't see a good way of
putting them thru the drilled hold in the brass tubing. Anyone know of
something else that would come in a squeez type applicator that might do
the job and be available locally? Water ingress and making the hardline
connection strong I see as the biggest problems. Otherwise I think just
using a small plastic or metal box and solder and clamp on wires forming
some type of connection to a PL-259 or SO-239 are about the only other
alternative I can think of. Of course using 75 ohm coax and having a 'bump'
in the impedance will be an interesting challenge to see how that works
with my Steppir or other antennas designed for 50 ohms.

The hard line does ohm out good so that seemed a good sign. Isn't it fun
using cast off coax from cable TV companies?
Terry/KI7M
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In the past I have used CATV hard-line (1/2 and ~3/4 inch diameter) and
modified the commercial connector
they use that has shoulder threads that match those of the PL-259 connector
we Hams use plus a  L O N G  center connector that engages their hardware.

To make my conversion to a type-N RF connector I did the following:

1 - Remove the threaded sleeve from a Male  PL-259  connector. Save the
sleeve and discard the remainder
2 - Cut off the portion of the sleeve that has no internal threads
3 - Thread the modified sleeve on the CATV connector
4 - Modify a type-N female barrel by shaving off the non-threaded portion
of the *non-crimped* end of the barrel
5 - Reduce the CATV connector's center-pin diameter and length to
accommodate the modified Type-N F-barrel
     when it is screwed into the modified PL-259 sleeve.
6 - waterproof to your standards

This worked fine for me when used to feed 1296MHz RF into 100-feet of CATV
line to an antenna on the tower.
Should work fine on 160-meters !

73 Dick/w7wkr at CN98pi