From: N8UG
Full-Name: Press W Jones
To: dick.green@valley.net
Cc: cqwire@juno.com
Subject: Re: [TowerTalk] Soldering PL-259 Connectors
References: <199708082212.SAA29418@norwich.valley.net>
X-Status: Unsent
Dick, there are many good bits of advice in your PL259 installation
suggestions, but there are several points that I would constructively
criticize, and with your willingness to listen to such assumed, I will
insert comments in CAPS and insert them in your text where they are
relevant. I will also post it to the reflector, as I feel strongly about
the subject and they are a major part of our livelihood (we put them on
here by the hundreds)73,::Press Jones, N8UG::The Wireman, Inc.::Landrum,
SC 29356::use n8ug@juno.com or (864) 895-4195 for tech help::orders only
use 800-727-WIRE(9473) or cqwire@juno.com<snip>>>I've been soldering a
lot of connectors lately, so, for what it's >worth, here's my method. I
think I got most of it off the HamCall CD-ROM:> First, I prefer to use
the silver plated connectors. I've always >found it to be very difficult
to solder the chrome plated connectors, no matter >how hot the iron gets.
THE NICKEL-PLATED PL'S SHOULD BE JUST AS EASY TO SOLDER AS THE SILVER
PLATED TYPES ----- AFTER THEY ARE PREPARED. THERE IS OFTEN A TRACE OF
FABRICATION LUBRICANT REMAINING ON THEM THAT CAN CAUSE SOLDERING
DIFFICULTY, ESPECIALLY IF THE IRON IS NOT HOT ENOUGH OR HEAVY ENOUGH TO
RETAIN ITS HEAT IN THE PROCESS. A QUICK WIPE WITH ALCOHOL, OR A SPIN OF A
PENCIL ERASER WORKS WONDERS. THE PROPER IRON IS THE MOST IMPORTANT
FACTOR, HOWEVER, AND IF USED, SOLDERING IS THE SAME ON EITHER
STYLE.SILVER PLATED PL'S HAVE ONLY ONE SIGNIFICANT ADVANTAGE AT THE
FREQUENCIES FOR WHICH THEY ARE MOST USED --- THEY TRULY ARE A CINCH TO
SOLDER. BEYOND THAT, THEY HAVE LITTLE, IF ANY, ADVANTAGE, ASSUMING EQUAL
QUALITY; INDEED, RF-WISE, THE NICKEL IS BETTER THAN SOME OF THE CHEAP
JUNK SILVER IMPORTS. MUCH MORE IMPORTANT IS THE DIELECTRIC. THE QUALITY
SILVERS HAVE TRUE TEFLON, THE CHEAPIES HAVE WHITE PLASTIC THAT RESEMBLES
TEFLON BUT HAS NO WHERE NEAR THE 200 DEG CMELTING POINT OF TEFLON. THE
ADVANTAGE OF THE TEFLON IS THAT IT LESS LIKELY TO BECOME USELESS AFTER AN
INADVERTANT ARC -- OTHERWISE, THE GOOD OLD PHENOLIC YOU SEE IN THE
STANDARD AMPHENOLS IS EVERY BIT AS GOOD.However, the following method
should work for either type.Enlarge the four holes in the connector
shell. You can use a drill, but I prefer a reaming tool. Making the holes
a little larger makes it easier to get the tip of your iron into the
holes.STOP -- PLEASE DON'T DO THIS. THE HOLES ARE THE RIGHT SIZE IN THE
FIRST PLACE. ENLARGING THEM REMOVES THE PLATING, WEAKENS THE BODY, AND
GREATLY INCREASES THE RISK OF A POOR INSTALLATION. TINY FILINGS CAN BE
OVERLOOKED, BURRS CAN BE MISSED AND LATER KNOCKED OFF BY THE COAX WHEN
INSERTED, AND THE SOLDERING OPERATION BECOMES MUCH MORE LIKELY TO CAUSE
FAILURE. THE CORRECT IRON, WITH THE CORRECT HEAD HAS A DULL POINT WITH
ANGLES THAT ALLOW IT TO PENETRATE THE HOLE ONLY FAR ENOUGH TO REACH
THROUGH THE HOLE, NOT BEYOND. THE FLOW OF SOLDER CARRIES PLENTY OF HEAT
TO HEAT THE BRAID AND COMPLETE THE BOND. IF THE POINT GOES IN TOO FAR IT
TOUCHES THE BRAID AND ONLY EXPERT TECHNIQUE KEEPS IT FROM ALLOWING MOLTEN
SOLDER TO PROCEED THROUGH THE DIELECTRIC TOWARD THE CENTER CONDUCTOR LIKE
WATER. THIS IS 7-800 DEGREE SOLDER ON PLASTIC THAT MELTS AT LESS THAN 180
DEGREES. IT MIGHT NEVER CAUSE A SHORT, BUT IT CAN CAUSE A MAJOR PROBLEM
AT FULL RF POWER IF IT EVEN GETS HALF WAY. THE MAJOR CAUSE OF FAILURES
THAT WE ARE CALLED UPON TO REPAIR ARE IN THIS CATEGORY. A COLD SOLDER JOB
IS EASY TO SPOT - THE KIND THAT LOOKS GOOD BUT WAS OVERHEATED HAS TO BE
OPENED TO SEE WHAT WAS WRONG. Don't enlarge them(the holes) too much or
theconnector will deform when you screw it on the cable.NOT AT ALL IS
JUST RIGHT.>Strip off enough of the outer jacket so that when the
connector is >screwed on, about 1/4" of the center conductor will stick
out the end of the >center pin.IF YOU DO A LOT OF THEM, MARK THE CORRECT
LENGTHS ON THE BENCH, OR EVEN ON ONE OF THE TOOLS - I THINK MY #1
TECHNICIAN HAS A MICROMETER IN HIS EYEBALL!>Lightly tin the shield braid
from where it exits the end of the jacket to about 1/2 inch or so. Avoid
thick lumps of solder on the braid and use >care not to melt the
dielectric.CONSIDER THIS OPTIONAL AND NOT PREFERRED. MANY COAXES HAVE
TINNED BRAID, MAKING IT UNNECESSARY, AND GOOD, CLEAN NEW COAX WITH BARE
COPPER BRAID ACCEPTS THE RIGHT SOLDER QUICKLY, PRECLUDING THE NEED FOR
PRE-TINNING. THIS PROCEDURE, IF FOLLOWED, REQUIRES GREAT CARE, FOR THE
SAME MELTING POINT REASONS MENTIONED EARLIER. FOAM DIELECTRIC IS EVEN
MORE DELICATE, AND SHOULD NOT BE TOUCHED BY MOLTEN SOLDER. PROFESSIONAL
INSTALLERS SELDOM, IF EVER, PRE-TIN BRAID. > Use a tubing cutter to cut
the soldered shield braid 3/8 inch from >the jacket, then pull the
remaining shield braid off. If the tubing >cutter isn't real sharp, it
will compress the soldered shield braid, making >it hard to just pull off
the unused braid. In this case, just cut it down the >middle with some
snippers and peel it off.TUBING CUTTERS ARE MEANT TO CUT PIPE THAT HAS
HIGH OPPOSING STRENGTH, NOT TINNED BRAID. THEY ARE NOT SHARP ENOUGH EVEN
WHEN BRAND NEW, AND ARE DIFFICULT TO IMPROVE, AT BEST. THE COMPRESSION
REFERRED TO IS ALSO HAPPENING TO THE DIELECTRIC IN THE CASE OF THE
VARIOUS FOAM DIELECTRICS. THIS IS NOT GOOD, SINCE A SHOULDER OF
DIELECTRIC IS REQUIRED TO INTERFACE WITH THE INNER FACE OF THE DIELECTRIC
IN THE CONNECTOR OUTSIDE OF THE BASE OF THE CENTER PIN IN A CORRECT
INSTALLATION. THIS REQUIRES A CLEAN CUT WITH A SHARP TOOL SUCH AS AN
ELECTRICIAN'S KNIFE, OR QUALITY STRIPPING TOOL. WE STILL FAVOR A RAZOR
SHARP KNIFE (POCKET OR OTHER) AND TINY WIRE CUTTERS FOR BRAID(CUTICLE
SCISSORS ARE GREAT), HEAVIER CUTTERS AND COAX CUTTER. NEVER HAVE FOUND A
TOOL FOR RG8 THAT IS BETTER THAN OUR KNIFE! Strip the dielectric to bare
the center conductor, leaving about 1/8 >inch of it intact after the
shield braid (this buffer helps to keep the two>conductors from shorting,
which can happen if molten solder drips down >the center pin tube).
MOLTEN SOLDER SHOULD NEVER GO ALL THE WAY DOWN THE PIN TUBE. HALF WAY IS
PLENTY ON A TOUCH AND TOUCH BASIS TO BUILD A SOLID PLUG AT THE END.Tin
the exposed center conductor.ON STRANDED CENTER CONDUCTORS ONLY, AND, IT
HELPS IMMENSELY TO EXPOSE AND TIN AS MUCH AS AN EXTRA INCH ON THE
STRANDED 9913 TYPES, THE NEW 9913F, ETC. IT CAN THEN BE CUT TO THE RIGHT
LENGTH WITHOUT DISTORTING IT - THE TOLERANCE IS SMALL. THIS APPLIES
MOSTLY TO "N" CONNECTORS, BUT IS GOOD PRACTICE ON PL'S - THEY DON'T ALL
HAVE THE SAME ID PINS. THE CONDUCTOR TINNING MUST ALWAYS BE BY "WICKING"
- NOT "SLATHERING" >Slip the screw ring on the cable (actually, always
do this at the >beginning so you don't forget) FOR SURE, and screw the
connector onto the cable. On most cables, I prefer to do this by hand.
Often I have to wrap the connector with>some cloth to get a good tight
grip on it.EXCELLENT PRACTICE. A TOUCH OF SILICONE GREASE OR EVEN
VASELINE ASSURES GETTING IT ALL THE WAY ON AND DOES NO HARM. Sometimes
I've had to use pliers to grip the connector, but care must be used to
avoid crushing or deforming it.LOOSE JAW OLD FASHIONED PLIERS ARE BEST,
EMPLOYED AT THE KNURLING BETWEEN THE SOLDER HOLES AND PIN. Some people
use a second pair of pliers to hold the cable,FORGET IT - START OVER WITH
A TINY BIT MORE GREASE, AND A CLEAN DRY HAND GRIPPING THE COAX. but I've
always has trouble with damaging the cable this way.AND ONE ALWAYS WILL
The important thing is to avoid twisting the cable.RIGHT. BOTTOM IT VERY
SNUG IN THE PL, THEN BACK OFF A HAIR IF A TWIST IS APPARENT. This
sometimes happens when there's a tight fit between the shield braid and
the inside of the connector, so be sure to tin the braid lightly (that
also helps to avoid melting the dielectric.) BETTER TO NOT TIN>Some
people recommend greasing the cable jacket with a little soap to make >it
easier to screw the connector on. I think I tried it once and it
helped.OK BUT SOAP IS WATER BASED AND SHOULD BE AVOIDED - SEE
ABOVE>Solder the shield braid to the connector through the four holes. Be
sure to>sure to use an iron that's hot enough. I've always gotten the
best results>with a Weller temperature controlled iron with a fairly
large tip. SEE EARLIER COMMENTS. ABILITY TO HOLD TEMP IN FLOW RANGE IS
MORE IMPORTANT THAN TIGHT CONTROL, THEREFORE A HEAVIER HEAD AND HIGH
WATTAGE IS THE IMPORTANT FEATURE. AT LEAST 100 WATTS IS REQUIRED TO DO IT
RIGHT. >Keep the tip of the iron well tinned.CORRECT, AND IMPORTANT I
usually heat the edges of the hole first, to get the connector hot enough
to melt the solder, then push the iron through the hole to heat the
braid.APPLY THE HOT IRON AND THE SOLDER AT THE SAME TIME TO #1 HOLE AND
IT SHOULD FLOW FREELY IMMEDIATELY. LINGER ONLY 5 SECONDS AND MOVE TO #2
-- #1PROBABLY WON'T BE DONE, BUT THE CONNECTOR IS NOW PRE-HEATED AND #2
SHOULD COMPLETE IN A FEW SECONDS, AS SHOULD 3 AND 4. TOUCH UP #1, QUICKLY
INSPECT, AND QUIT. A DAMP RAG IN YOUR PALM TO WRAP IT FOR A FEW SECONDS
DRAWS THE HEAT OUT RATHER THAN LETTING IT MELT JACKET, ETC. IF THIS
SOLDERING PROCEDURE TAKES MORE THAN A MINUTE, IT WAS POORLY DONE. IT
HELPS A LOT TO HAVE A HELPER TO HOLD THE ROLL OF COAX AND ROTATE THE
MASS WHEN YOU COMMAND. WE USE A JIG, BUT THAT IS A PRODUCTION TOOL. When
both are hot enough, the solder will flow freely into the hole and sag
downward into concave shape. If it's balling up or is convex, the iron is
not hot enough or needs to be tinned. If you move quickly from hole to
hole, the connector will retain most of the heat and you won't have to
reheat it much to solder through the next hole. Thatavoids overheating
the dielectric.CORRECT, EXCEPT FOR THE PREHEAT -- THE SOLDER SHOULD HIT
THE HOLE WITHIN 1 SECOND OF THE IRON'S CONTACT.Solder the center
conductor to the center pin. Be careful not to drip >too much solder down
the center pin tube -- it can slip past the center>conductor and short
the shIeld braid.HALFWAY DOWN IS PLENTY -- TOUCH AND TOUCH>Use an
ohmmeter to check for proper continuity and shorts between the >shield
and center conductor. If you're making a cable with connectors at both
>ends, hook up a dummy load and make sure the SWR is flat.EXCELLENT.AGONY
CAN BE AVOIDED BY CHECKING W/METER ONE CONNECTOR AT A TIME, BEFORE AND
AFTER SOLDERING. MADDENING TO BE OVER-CONFIDENT, THEN FINDING A SHORT,
AND TRYING TO GUESS WHICH END IS THE CULPRIT!! Hope this is helpful. ME
TOO(N8UG)!>>73, Dick , WC1M>>-->FAQ on WWW:
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