GB> Re: [Boatanchors] PL-259 Soldering

Jim Wiley jwiley at alaska.net
Thu Oct 11 23:27:18 EDT 2007


All -   this is a bit long winded, but it works.


For a "bulletproof" PL-259 connection, try this: 


Tools needed:    Propane torch, box knife, wire cutters, solder, 
soldering iron


Trim off about 2 or 3 inches of the outer plastic sheath, then tin the 
outer braid completely.  When it is cool (blow on it with an air gun or 
just wave it around for a while).  Cut the tinned braid to the length of 
the inside of the PL-259 barrel (hold it up next to the barrel for 
sizing).  I use a box-knife, but a tubing connector works just as well.  
When cutting the braid, I carefully continue the cut so as to cut the 
inner insulation almost all the way down to the center conductor, being 
sure not to nick the conductor - but if you do the next step will fix 
this problem.  You should have enough center conductor protruding to 
completely go through the center pin with a bit extra.  Tin the center 
conductor completely (flow solder along the entire length of the exposed 
wire.  The soldering process will effectively repair any nicks as long 
as the strands are not completely cut through - in fact, even if a 
strand or two is broken, as long as they are still in place, the solder 
will correct the problem.  When the solder has cooled, place the cable 
in the connector body, and trim the center conductor flush with the end 
of the center pin.  Solder the center conductor to the pin.   Again, 
when cool, put the cable assembly into a vise (or something else to hold 
it still) with the cable protruding out about 4" on the connector side.  
Place things so one of the holes in the connector body is "up".  
Soldering the center conductor helps keep everything in place while 
soldering the shield in the next step.


Now, comes the torch.  I use a standard "Bernz-o-matic" hardware store 
variety propane torch. The idea here is to get in with enough heat to do 
the job, and then get out before the rest of the parts get hot enough to 
damage something.  With solder in one hand, and the torch in the other, 
heat the connector body for 7 to 10 seconds.  Put the inner bright blue 
cone of flame directly on the connector body at transition between the 
"holes" and the front portion of the connector.  Next, place the solder 
into one of the holes and press gently.  As soon as it melts, remove the 
heat.   Keep the flame directly on connector until the solder flows 
easily.   Do not get the flame on the ends of the connector.  Once the 
solder starts to flow, remove the flame.  You might need to "kiss" the 
connector body with the torch flame a couple of times while adding 
solder.  Be sure to use ample solder.  I use enough so that the excess 
starts to flow out the "bottom" hole.  Then put the torch away, and turn 
it off!   It is easy to relight for the next connector, and you really 
don't want to take the chance of knocking a lit torch over onto your 
bench.  


The time it takes to turn off the torch and remove the cable from the 
vise is about the right amount of time to allow the solder to set up.  
Now you can cool the connector by rolling it around on a wet cloth.  
When it stops steaming, let it cool the rest of the way in air.  Use a 
compressed air blow gun if you have one, otherwise just wave it around 
or blow on it,  or use a hot-air gun  on "cool".   Just an afterthought 
- If you do this right, and trim the outer braid so just a bit of the 
plastic insulation is still inside the rear of the connector body when 
everything is pushed together, the heat will melt the bit of sheath and 
make an almost water tight seal.  I know, I know - the rest of  the 
connector is not water tight, but this cannot hurt, can it?    Now you 
have a connector and cable assembly that will never, ever, come apart. 
The 10 seconds or so of torch heat is much preferable to grinding on the 
connector for a minute or more with a low-powered pencil iron or a 
solder gun.


There is a slightly different procedure for using RG-58 reduction 
adapters that works just as well.  In that case, strip off about 2" of 
the outer sheath, and put inside the adapter until the plastic just 
comes to the "front" end of the adapter.  Separate the braid into 
individual strands, and fan it out at the edge of the adapter.  A "file 
carding tool" is excellent for this job.  Trim the braid wires until 
they are almost flush with the sides of the adapter - they will be about 
1/8" long at this point.  Now, using a conventional soldering iron, 
carefully solder the braid wires to the very end of the adapter that is 
closest to the front.  Do not solder any of the wires to the sides of 
the adapter. 


When the solder is cool, carefully trim the braid wires flush with the 
sides of the adapter.  You should have an assembly that has just a small 
ring of soldered braid wires at the very front.  Strip the center 
conductor, leaving about 1/8" of insulation, and tin the wires 
completely.  Make a test fit.  If the adapter will not screw into the 
PL-259 easily, you may have to file the soldered area slightly to allow 
the two parts to mate. Screw the adapter into the PL-259, and tighten 
with two pairs of "gas" pliers until they are very tight.  Do not solder 
the adapter to the PL-259!  It is not possible to get enough heat to 
make a good solder joint without melting the inner conductor!   Of 
course, solder the center conductor to the PL-259 center pin, , but in 
this case only after the parts are screwed together. 


Good luck!


- Jim, KL7CC



Scott Johnson wrote:
> I am somewhat confused.  I have soldered all manner of PL-259, both 
> silver and nickel plated, and although the nickel alloy is not the 
> easiest metal to tin, it tins at least as well as brass.  I have never 
> had a problem soldering the (pre-tinned) braid to the connector body.  
> What works best for me  is a 1/8' chisel tip on a Metcal, or the 
> chisel style tip on a Weller gun.  I use RA flux Kester .062" 63/37 
> solder.  My connectors always come out fine, and I do use a very we 
> sponge or rag to cool the connector, and I clean off the flux 
> carefully afterwards, as it is very hygroscopic and will hold 
> moisture.  BTW, you can still purchase the Ag plated connectors, they 
> are just pricier by a buck or so, but probably worth it.  I assume 
> someone already mentioned pre-tinning the braid, and trimming it to 
> length with a tubing cutter?
> regards,
> Scott W7SVJ
>
> john wrote:
>> I have been doing this for some time and it really works well. If you 
>> tin the newly exposed brass before beginning the process, it works 
>> even better. With a large iron (like American Beauty) with a lot of 
>> thermal mass, it makes soldering these things quite easy.
>>
>> I also would add dampening a sponge, so that when you're finished 
>> with the solder joint, you can cool the housing off by pressing it 
>> into the damp (not wet) sponge, minimizing the time the heat has to 
>> soak into the inner insulator, perhaps melting it.
>>
>> With a high thermal mass iron, it takes very little time for the 
>> housing to get to reflow temp (and thus less chance of melting the 
>> inner insulator sheath.
>>
>> Thanks Sandy!
>> John K5MO
>>
>>
>>
>>
>> At 08:55 PM 10/11/2007, Sandy wrote:
>>> Mike,
>>>    Many thanks for posting it someplace!  It's not really my idea, 
>>> someone else told me about the trick years ago.  Amphenol used to 
>>> plate the connectors with something that took solder ( silver, at 
>>> one time) but they plate them with something that is hard to "wet" 
>>> with solder now (with rosin core flux).
>>>    Hope this helps you guys like it's helped me over the years.
>>>
>>> 73,
>>>
>>> Sandy W5TVW
>>> ----- Original Message ----- From: "WE0H" <we0h at yahoo.com>
>>> To: "Sandy" <ebjr37 at charter.net>
>>> Cc: <boatanchors at mailman.qth.net>; "Glowbugs reflector" 
>>> <glowbugs at piobaire.mines.uidaho.edu>
>>> Sent: Thursday, October 11, 2007 3:57 PM
>>> Subject: Re: [Boatanchors] PL-259 modification...pic online now...
>>>
>>>
>>>> Here's the link to Sandy's picture.
>>>> http://www.we0h.us/tmp/PL-259-Modification.jpg
>>>>
>>>> Mike
>>>> WE0H
>>>>
>>>>
>>>> -- 
>>>> No virus found in this incoming message.
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>>>>
>>>
>>>
>>>
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