Preparing Some Test
Probes
The key to successfully making
LocoNet cables and installing RJ12 telco jacks is to test your work each
step of the way. This is very simple to do and will save you lots
of headaches. Making these test probes will also be good practice
for stripping and tinning the 6 wires. The photos below show how
we make our "test probes" - two pieces of cable with a male plug crimped
to one end and the wires stripped and tinned on the other.
-
Using a sharp utility knife, carefully
knick and strip about 6 inches of the outer plastic casing from an 18"
-24" length of RJ12 flat cable.
-
Using a butane BBQ lighter, melt
about 1" of the plastic coating off the white wire.
-
You might be tempted to use a set
of wire-strippers to strip the plastic coating off the wire. Don't!!
You either cut the whole wire, or you'll cut a few copper strands.
-
You've now exposed some very fragile
wires. Carefully twist the exposed copper strands on the white wire
-
Flux and tin the exposed wire so
that you have a thick strand. You'll notice how the soldering iron
melts a bit more of the plastic.
-
Notice how melting the plastic has
added back some of the stability. You wouldn't have that same stability
if you tried to strip the plastic using some wire strippers.
-
You've now converted some fragile
wires into a more stable wire - but it's still fragile!
-
Repeat the above process for the
other 5 wires.
-
Crimp an RJ12 male plug on the other
end.
-
Repeat the above steps for another
piece of cable.
Here's some photos
of the above steps.
I've stripped the outer plastic casing
back about 6". I took a utility knife, scored the plastic casing,
and then pulled off the casing with a pair of pliers. If necessary,
score the plastic casing again but make sure you don't nick the coloured
plastic insulation on the wires. If you do, start all over again.
Once, I got the casing off of the flat cable, I took the white wire
and melted about 1" of plastic off the white wire with a butane BBQ lighter.
I then twisted the exposed copper wires on the white wire and fluxed
the twisted wires, in preparation for applying some solder.
In this photo, I've melted, fluxed, and tinned all six wires.
I'm ready to crimp an RJ12 male plug on the other end.
And voila! I have a pair of test probes. All I need to complete
our testing is an ohmeter. We simply plug one of our test probes
into a throttle jack, plug the other probe into a connected throttle jack,
and, in turn, test the continuity in each of the wires using our ohmeter.
However, before
we start wiring up some RJ12 throttle jacks, we're going to discuss that
ubiquitous female-female "gender bender". |
