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RE: [BULK] - RE: [TowerTalk] Re: Cutting braid - Installing PL259

To: "''" <>,'Tower Talk' <>
Subject: RE: [BULK] - RE: [TowerTalk] Re: Cutting braid - Installing PL259
From: Steve Katz <>
Date: Mon, 17 Jan 2005 09:54:47 -0800
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Same here Bud.  My guess is most hams have been frustrated by this task.

Here is how I solved the problem once and for all:

1. Obtain a professional temperature controlled soldering iron with moderate
to wide blade tip.  My choice is Weller digital adjustable temp.
2. Strip the cable jacket as usual so that center conductor will reach the
tip of the PL259 and jacket is removed where shield will be soldered.
3. Set iron to 650 degrees.

::Might work, but a pretty aribtrary setting.  It isn't the temperature
that's important, it's how fast you can transfer the heat from iron to
connector.  For efficient transfer, the thermal mass of the iron should be
considerably higher than the thermal mass of the connector.  That's really
the only important issue. (WB2WIK/6)

4. Tin braid where it will be soldered.  Be sure to tin all the way around.
Be careful not to overheat and melt the dielectric.  Apply solder and tip at
the same time in several spots, then flow all together without adding more
solder.  You may need to add more solder if initial application will not
flow all the way around.

::Might work, also, but absolutely NOT recommended by the military
specification for soldering PL connectors, and also NOT recommended by the
connector designer, Amphenol (who was American Phenolic Co. in 1945 when
they started producing them).  Also strongly not recommended for anyone
using cellular poly dielectric cable, like RG8X, FM-8, LMR400 or anything
else that's "foam," because the cellular dielectric has a very low melting
point.  Luckily, there's absolutely no reason to tin the braid of cable that
already has tinned braid, which LMR400 does.  But we need to be really
careful with RG8X and such. (WB2WIK/6)

5. Using a small tube cutter (1 inch is easiest to use), cut off the braid
and dielectric at the point where the dielectric will butt up to the
connector bottom and allow center to reach tip.  Double check that none of
the braid has bent down and contacted the center.  If the tinning step was
done correctly, this should not be a problem.  Any excess tinned braid can
be bent back up and nipped to prevent contact.

::I wouldn't do this. (WB2WIK/6)

6. Insert cable into PL259.

::This most critical step was pretty glossed over, here.  You don't "insert"
the cable into a PL-259!  The connector *THREADS* onto the cable jacket, and
pulls itself onto the cable by doing so.  It takes at least three full
rotations (1080 degrees) to properly thread a PL-259 onto its mating coax,
and if you don't do this step, everything else is pretty irrelevant, because
you won't have a good installation. (WB2WIK/6)

7. Apply solder and tip to each hole to bond braid.  I like to begin with a
small amount at first, then lift tip and solder.  Then do a second small
amount.  Continue until hole is just filled.  By this time heat should be
sufficient to flow the solder, but not high enough to melt the dielectric.
Proceed slowly but surely to fill all holes in this manner.

::If you proceed slowly and use this method, you're really taking a long
time to do a very simple job and very likely overheating the dielectric in
the process.  Using a large-mass iron (American Beauty, etc), it takes five
seconds to transfer full wetting heat from iron to PL-259 body and flow the
solder into the holes, with the iron pulled away and absent during this
latter part of the process.  (WB2WIK/6)

8. Solder the tip in a similar manner, applying dabs of solder and heat
until tip is filled and flows, but not hot enough to wick solder up to the
butt end of dielectric.

::I'd recommend waiting until the connector body cools off so it can be
touched before soldering the center pin at all.  This provides some time for
the dielectric to reform without much distortion.  To accelerate this
process, once the solder is fully solid, I just apply a large, damp sponge
directly to the connector body, rotate the assembly, and apply the same
sponge to the other side of the body.  That makes it cool to the touch in a
few seconds.  If you're soldering a lot of connectors, it pays to have a
bucket of cool water and a large sponge close by. (WB2WIK/6)

::As part of a business operation I ran for several years, we soldered
500-800 PL-259 cable assemblies per day, using only single-ended razor
blades (the original Amphenol recommended tool!) for trimming and American
Beauty 120W irons for soldering, along with .062" diameter 60/40 rosin-core
"radio" solder, and Amphenol 83-1SP (silver plated) connectors.  Post
process testing included a 60-pound linear pull test (calibrated) followed
by an end-to-end cable assembly RF sweep to 300 MHz, and experienced about
99% manufacturing yields using a process that takes less than 60 seconds per
connector assembly, including cable trim time, per operator.  With three
operators, we could achieve 360 assemblies, and 720 connectors, per day in a
single shift, allowing 1 installation every two minutes total -- which
allowed cooloff time and tagging the cable with its S/N label.  (WB2WIK/6)


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