MOTM

I must be old fashioned (or else very agile.)   I use either of two methods 
to prepare coax ends.  If I want to use the coax braid to make the 
connection, I prepare the cable just like those that come ready-made with 
MOTM kits.  First I strip the insulation with my trusty all-purpose wire 
stripper, a simple hand tool permanently set for #24 gauge, but which I use 
for all gauges.  I'm careful not to nick the braid.  Then I bend the cable 
sharply and tease out the inner wire with a tiny sharp awl (much like the 
Swiss Army Knife corkscrew, but it's straight).  It's not too hard to pull 
the wire out, leaving the braid fully intact and now to the side.  Twist 
the braid and tin.   Strip the inner conductor and tin.  Done.  Tinning is 
easiest if you have a "solder pot" but I bet hardly anybody here (except 
maybe Paul Schreiber) needs to do that much assembly-line work.  A solder 
pot, in case you don't know is just that -- a small pot of molten solder 
that you dip your wires into for tinning.

The other method I learned while assembling avionics computers, long 
ago.  For this method, after you strip the outer insulation, bunch up the 
braid to form a lip and cut it off with dikes (or use a special 
tool).  Then wrap a 2-inch #24 gauge stranded pigtail around the remaining 
braid and solder it before covering with a piece of heat shrink.  Now you 
have a very tidy set of wires to connect - no braid in sight.  A heat gun 
comes in handy.  It is also possible to use a "solder sleeve", which is a 
bit of heat shrink prepared with a ring of solder inside it.  Using the 
high heat setting on your heat gun, you can solder the pigtail and shrink 
it all in one shot.  I prepared hundreds of coax cables that way and it 
goes pretty fast.  I don't bother with solder sleeves now because I don't 
have a great quantity to do and I'm bold enough to solder the pigtail with 
my soldering iron.  Yes, you risk melting the inner insulation, but it's a 
small risk if you are practiced.

I did try a coax stripping tool for the RG-59 cables I made to carry video 
-- be glad you  don't have to deal with BNC connectors -- ages ago and 
didn't like it much.  But if I had to do a lot of coax prep, I would look 
into getting one.

Oh, and I don't plan on using coax for the MOTM-320R mod.  I will just use 
twisted pair.  (Tip: Cut two long pieces of colored wire, say 10-foot 
each.  Use different colors of course!  Knot them togther at one end and 
clamp in a vise.  Put the other ends into your electric hand drill.  Keep 
it taught...  zrrssh.... nice twisted pair.  I used to go out into the 
corridor at work and make twisted pair this way with 50-foot lengths.)

-Richard Brewster (who spent too much time in his youth on assembly lines)


At 10:19 AM 10/21/03 -0600, Adam Schabtach wrote:

> > If you're going to be doing a lot of DIY get a dedicated coax stripper and
> > you'll be MUCH less grumpy.
>
>I have one of those automatic strippers with the clamp on the left and the
>blades on the right, with notches for 10-22ga wire. The largest notch works
>well for stripping the outer jacket of small coax.
>
>The other trick I've discovered is using the corkscrew on a Swiss Army knife
>to unbraid the shield. It's pointy but has smooth sides, so it teases the
>braid apart without nicking and breaking the strands.
>
>I'm sure that a dedicated coax stripper works better, but these are
>techniques born many years ago, from a small budget. :-)
>
>--Adam