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.
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On Sat, 18 Jan 2014 20:22:18 -0800, the renowned Bob E.

If it's like this cr*p they sell at Home Despot, it's copper clad steel core with an _aluminum_ braid shield:-
http://www.cerrowire.com/files/file/49223_CERRO_CoaxialCable_6U_QUADLR.pdf
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
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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...
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On Sat, 18 Jan 2014 20:50:34 -0800, the renowned Bob E.

I guess there's always better stuff like this:-
http://nordencommunication.com/download?file 60-RG_6u.pdf
Best regards, Spehro Pefhany
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"Bob E." wrote:

You must do lousy crimping, if you lose a dB.
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Michael A. Terrell scribbled thus:

I agree ! A good crimp is at least as good as the best solder joint.
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Baron wrote:

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.
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On 01/18/2014 10:50 PM, Bob E. wrote:

I would have thought every soldered joint is one more reflection.
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I'm no RF expert, just my impression--possibly mistaken.
Thanks.
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"Bob E." wrote:

The loss should be under .1 dB for a good F connector, ant they are used into the GHz range.
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On 1/19/2014 2:30 AM, Michael A. Terrell wrote:

^^^^^^^^^^^^^^^^ Jumbo shrimp alert. ;)
Cheers
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Phil Hobbs wrote:

There are good ones, but you won't buy them at retail stores.
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On 01/19/2014 10:48 PM, Michael A. Terrell wrote:

Use Snap-N-Seal type F-connectors. They are moisture proof and positively crimp correctly.
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On 01/20/2014 08:46 AM, dave wrote:

I don't have TV at home, and there's no way I'd use F connectors for anything but entertainment.
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On Mon, 20 Jan 2014 11:10:46 -0500, Phil Hobbs

Ok, I'll bite. What's wrong with F-connectors? There are zillions installed on indoor and outdoor CATV installations with no failures or issues. Certainly there are connectors with better specifications, but for the intended purpose and cost ($0.30/ea), F-connectors are more than adequate. The only real problem I've found is the wide variety of cables claiming to be RG-6/u. Making a connector that will fit all these RG-6/u mutations is tricky, but T&B has done a decent job with their "red" SNS1P6U Snap-N-Seal connectors: <http://www.ebay.com/itm/221344116756
So, what's wrong with F-connectors and what would you recommend the CATV industry use instead?
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On 01/20/2014 12:49 PM, Jeff Liebermann wrote:

If the CATV industry likes them, well, I'm happy they're happy. Instrument use is quite a different regime. F connectors use the centre conductor of the coax as the contact, and are very susceptible to damage with repeated mating cycles. The ones I've seen are also fairly far from constant-impedance.
BNCs and SMAs for me.
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On Mon, 20 Jan 2014 16:13:00 -0500, Phil Hobbs

The CATV industry is never happy. If it were happy, innovation would cease and the status quo would become permanent.

I believe that I mumbled something about "for the intended purpose". I don't think anyone uses F-connectors for precision test equipment. They're not really good enough. Looking at the pile, most of my CATV specific test equipment uses BNC connectors. However, that's not because the F-connector is in some way electrically inferior. It's because the F-connector receptacles were not designed to survive repeated insertion/removal cycles. The few that have built in F-connectors allow for easy replacement, such as my Wavetek SAM-1000 which uses a panel mounted F barrel adapter.
The F-connector is certainly not constant impedance. On a TDR, the bump is rather obvious. Yet, some cable and connector combinations are rated and tested to 4.5GHz: <http://www.tselectronic.com/shop/product/1694A-Belden-4.5GHz-RG6-U-Precision-Video-Cable-for-Analog-and-Digital-Applications/1026 The recommended connectors are T&B SNS1P6 or FSNS6U compression F-connectors.
I partly agree with you about center conductor problems. I assume that you're referring to the copper plated steel center conductor, found in most cheap RG-6/u cables, which is not intended for repeated insertion/extraction cycles. Still, the rating is 500 insertion/extraction cycles minimum. The copper will eventually scrape off. However, solid copper center conductor RG-6/u (such as Belden 1694A) works quite nicely, without any damage. I couldn't find a spec for insertion/extraction cycles for 1694A.

Crimp or compression plugs, in quantities of 100 on eBay: F-connector $0.30/ea SMA male $0.70/ea BNC male $1.00/ea For test equipment, the price difference is not enough to justify using the cheapest. For CATV, which consumes connectors by the millions, every penny counts.
Thanks.

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On 1/20/2014 6:41 PM, Jeff Liebermann wrote:

Sure, horses for courses. I'm not telling them how to run their lives, because I couldn't care less about their lives. ;) (Well, as individuals, sure, but as for the industry, if CATV went away completely tomorrow, it would suit me fine--provided only that they took their tarts and talking heads with them.)
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On Mon, 20 Jan 2014 18:55:56 -0500, Phil Hobbs

I assure you that the selection of RF connector will have no effect on CATV content quality. I like the tarts, but can do without the talking heads.
For what little it's worth, I didn't own a TV for about 15 years. Except for being somewhat culturally deprived, I didn't miss TV in the slightest. However, I then picked up a contract to review some technical videos and needed a TV and VCR to play them. I soon found myself watching broadcast TV, buying DVD's, putting together a media center, subscribing to DirecTV, Netflix, etc. Today, I find that I can't sleep without the TV running. I'm now watching a 1931 Boris Karloff movie as I type. I'm addicted.
Hint: Don't judge connectors by the content they carry.
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On 1/20/2014 8:41 PM, Jeff Liebermann wrote:

Nah, sufficiently crappy connectors could improve the content a lot. ;)
Cheers
Phil Hobbs
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