Unsolderable wire?

I am trying to solder some RG-6 shield to a pcb. The braid won't tin. It's
almost like it's dissipating the heat faster than I can apply it. With both a
temp-controlled iron (set as high as 700F) and a mondo 100W stick I finally
tried. The solder will barely melt when touched to the braid opposite the
iron.
I've applied some Kester rosin paste flux as well using my trusty Kester
60/40 lead-based rosin core solder. No joy. I'm not holding the braid against
the PCB now, I'm just trying to tin the braid and then deal with melting the
2 solders (on the PCB and the braid) together later.
My first attempt--before I realized that I was overheating it--I melted the
dielectric insulation.
The mesh is made from some silver-colored braid which I thought is tinned
copper but now I'm of the opinion that it's steel; it's certainly not
aluminum. There is also foil which is probably aluminum but I've trimmed that
back and it's not part of this frustrating process right now.
What's the trick to getting this braid to take solder? I've never seen this
before.
Thanks.
Reply to
Bob E.
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If it's like this cr*p they sell at Home Despot, it's copper clad steel core with an _aluminum_ braid shield:-
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That would explain the copper-like heat conduction that you're observing.
I suppose you could try an aluminum flux, but can't you just unravel and gather enough of the shield to crimp into a ring terminal or something?
Best regards, Spehro Pefhany
Reply to
Spehro Pefhany
It's not made to be soldered. It's CATV cable that's made for crimp on 'F' fittings.
Reply to
Michael A. Terrell
"Bob E."
** A magnet will pick up steel wire - but no Aluminium.
** Unplated steel or Aluminium wires are not solderable by ordinary means.
.... Phil
Reply to
Phil Allison
Twist the braid into a wire and butt splice on a copper wire. Heat shrink over it.
Reply to
Tom Biasi
Yes it's that crap.
Yeah, that's my next move. I just couldn't believe that something couldn't be soldered. I guess REALLY agressive flux is required, as you say.
When it comes to broadcast TV I try to solder every connection possible. Every crimp is one more dB lost.
Thanks.
Crimps in hand...
Reply to
Bob E.
I guess there's always better stuff like this:-
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Best regards, Spehro Pefhany
Reply to
Spehro Pefhany
You must do lousy crimping, if you lose a dB.
Reply to
Michael A. Terrell
I would have thought every soldered joint is one more reflection.
Reply to
cjt
I'm no RF expert, just my impression--possibly mistaken.
Thanks.
Reply to
Bob E.
The loss should be under .1 dB for a good F connector, ant they are used into the GHz range.
Reply to
Michael A. Terrell
yeah stainless steel braid, aluminium shield and a copper-plated steel core. most of the RG6 I've used is like that.
a solderable F connector socket is probably the best way to terminate it.
Give up! If you can't give up spot weld it to some tinned copper.
Reply to
Jasen Betts
If it's for personal use, tightly wrap a dozen turns of tinned copper wire (or silver plated) around the braid, twist the end together and solder to these.
Cheers
Reply to
Syd Rumpo
Aluminum is a poor choice for a crimped connection. Remember the problems with household aluminum wiring -- even when it was screwed down?
Reply to
William Sommerwerck
Electroplated wire, most likely nickel. Jamie
Reply to
Maynard A. Philbrook Jr.
Well, what does it feel like?
Steel wire feels very stiff. Grab a leaded component out of the box and ponder the leads; they're probably tin plated steel (check with a magnet). Most resistors, capacitors and diodes are. Some smaller ceramic caps have thicker, softer copper leads; find some if you can.
Aluminum wire is very soft, floppy stuff. It is much softer than copper, than copper is of steel. If that's what it is... oh well.
As for soldering practice... the old saw about "apply solder to the opposite side of the joint" is complete BS. Forget about it. Don't try soldering as you were told, make the solder happy and good joints will follow. First goal, get the part hot: hold the iron on the part, and apply solder right beside the iron, or to it, so the iron heats and wets what it's touching. On a braid, solder will spread and soon the joint will accept solder from all sides.
Tim
Reply to
Tim Williams
A solder pot is preferred. Otherwise burn all the non-metallic weirdness away with your trusty Zippo.
Reply to
dave
Michael A. Terrell scribbled thus:
I agree ! A good crimp is at least as good as the best solder joint.
Reply to
Baron
The entire CATV industry is built on crimped connections. It's amazing, the amount of misinformation in this thread. The braid is nothing more than drain wires, in continuous contact with the foil shield. It doesn't have to carry any power, so the random contact points all add up to a low resistance connection. As long as water doesn't get into the coax, it will likely outlast the installer. The .750", .500" and other sizes of hardline used is aluminum for both conductors. The .750" can carry 30A @ 60 VAC without problems.
Reply to
Michael A. Terrell

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