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Author Topic: CRIMP CONNECTOR  (Read 430 times)

WF3W

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CRIMP CONNECTOR
« on: June 20, 2022, 02:00:39 PM »

Gday all Hams,

Breathes there one of you who admits having problems with crimp PL-259s?

I do so, ashamedly and ask for Elmering. I have coax prep-tool [DXEngineering] and I get perfect stripping and cutting. My hand crimper was also purchased from DX [it has zero, identifying marks]

I have silver/teflon PL-259s. The ONLY thought I have — about crimp conn — is Im not soldering the center conductor properly or enough.

ALL cables homebrewed pass conductivity/continuity tests and they also look patent on my nanovna and AA-35 Zoom. The latest failure worked great, for one transmission, i.e., SWR 1.06 but the next transmission was a disaster at SWR 2.09 and only 8W on my LP-500.

I take full, and awesome, responsibility for my shack. I just want to fathom what Im doing wrong, why and how to correct it.

Ive never seen coax tossed across the room, pile-up so fast...

73
Phil, WF3W
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KB1NO

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Re: CRIMP CONNECTOR
« Reply #1 on: June 20, 2022, 06:28:51 PM »

My problem with Crimp/Solder PL-259's is related, but different.   I often get solder on the silver plating on the outside of the center pin. This could possibly damage the mating SO-239.  So I either wick it off or worse, file it off.   If I use less solder to try to avoid this,  I'm concerned that it will be an intermittent connection, as you have seen.       
So I tried using Crimp / Crimp PL-259's but soldering the center pin instead of crimping.  Some of the commercial manufacturers do this.
Since it's necked down there is less chance that slopped solder will affect the contact area with the mating SO-239.   But...
The actual contact area of the center pin is reduced by almost half.  Probably fine for 100W or QRP but may be a problem getting a good contact for high power.     
I'm interested in what others have done to solve the "center pin" challenge.   
73,
John, KB1NO
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WB6BYU

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    • Practical Antennas
Re: CRIMP CONNECTOR
« Reply #2 on: June 20, 2022, 09:34:44 PM »

Quote from: WF3W

I have silver/teflon PL-259s....




Let’s stop right there and make sure you are using the
right connectors.

A “silver / Teflon PL-259” is, at least in my experience,
a solder-type connector.  It doesn’t work with a crimper.

Crimped connectors come in two types:  one where you
crimp the center pin, and one where you solder it.
But you need the type specifically designed for crimping.
They also have to be designed for the cable type you
are using:  crimped connectors aren’t as generic as the
old original MIL-SPEC PL-259.


Now, I might not be up to date, and you may indeed
have the proper connectors for your cables.  But that is
the first thing to verify when you are having problems.
A crimp connector for RG-59, for example, won’t fit
RG-8X, even though the cables are the same diameter
(because the center conductors are different sizes).

Then the next step is to identify the failure mode:
Are the conductors shorted, or is the center or the
shield open circuit?  A DC test with an ohmmeter is
usually adequate.  Once you know that, you have a
better idea where to look for the problem.

G4AON

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Re: CRIMP CONNECTOR
« Reply #3 on: June 21, 2022, 01:00:34 AM »

Crimped coax plugs and sockets are fine if you use connectors from a manufacturers distributor and their recommended crimp tool… otherwise forget the idea.

Connectors and crimp tools from eBay, Amazon, flea markets, etc. are just too much of an unknown and you can end up with a poor crimp.

I personally prefer compression fitting plugs, especially those by the Italian company Messi and Paoloni when used with their coax.

73 Dave
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VK6HP

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  • Posts: 1222
Re: CRIMP CONNECTOR
« Reply #4 on: June 22, 2022, 02:27:39 AM »

I use the DXE crimp/solder PL259 connectors quite a bit, with the prep tools and crimper apparently the same as Phil (the OP).  I find it a very good combination for making reliable connections, with the soldered centre pin and the crimped outer.  To make reliable centre connections I always tin the coax conductor generously and the inside of the pin itself rather sparingly.  Hold the assembly firm on a gentle slope and, using a hot iron and very little additional solder, observe the solder melting and flowing slightly in the pin.  Stop at that point: if you keep going you'll end up with the situation described by KB1NO, where far too much solder causes a blob on the outside of the pin. As long as there's a good, shiny, well-flowed joint you don't need to go further.  It's much like all good soldering in that the mechanical disposition and stability of the pieces to be soldered is an essential part of making a good joint.

As Dale mentioned, doing some forensics on the failed cables is very important to see where the problem is.  One thing to watch is that the stranded centre conductor should be intact and not stressed/kinked within the connector assembly.  From the brief description Phil gave I wonder if there were only 1 or 2 conductor strands doing the initial job, but failing on subsequent flexing.

73, Peter.
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W9GB

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    • HomeURL
Re: CRIMP CONNECTOR
« Reply #5 on: July 02, 2022, 04:07:40 PM »

Phil -

Your issue is either
INCORRECT Crimp Connector for your specific Coaxial Cable
AVOID Unknown Brands that are Dirt Cheap (Knock Offs)
==OR==
HAND/EYE Coordination issues with your Tools.
This is Common with Radio Amateurs that only Install a Connector, a few times a year.  Some professional techs install hundreds each week or month.
==
Quote from: WF3W
My hand crimper was also purchased from DX [it has zero, identifying marks]
That is likely YOUR ISSUE. 
the HEX Crimp DIE CAVITY MUST be Correct for Coax Cable and Connector.

* DXE-UT-CRMP2 Ultra-Grip 2 Crimp Connector Hand Tool
* DXE-UT-DIE-8U Crimp Die works on connectors for RG-8U/213/LMR-400 size cable
* DXE-UT-DIE-8X Crimp Die works on connectors for RG-8X/LMR-240 AND RG-58/LMR-195 size cable

DXE CRIMP TOOL KIT INSTRUCTIONS
https://static.dxengineering.com/global/images/instructions/dxe-ut-kit-crmp2_zf.pdf
DXE DIE SET INSTRUCTIONS with HEX Cavity Sizing
https://static.dxengineering.com/global/images/instructions/dxe-ut-crmp2_fr.pdf

RF Industries Crimp Kits : Tools & Dies (Hex Cavity sizes)
https://rfi-instructions.s3-us-west-1.amazonaws.com/tools/rfa-4005-draw2.pdf
==
Suggest you Search on YouTube for
GOOD Technicians SHOWING YOU HOW.

W2AEW : Installing BNC Crimp on RG-58/U
https://youtu.be/ktQVwfo-s9w
« Last Edit: July 02, 2022, 04:20:43 PM by W9GB »
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