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SMA crimp plug

http://www.maplin.co.uk/p/maplin-sma-crimp-plug-rg58-mm55k

I have something like the above. Not pictured on the above link, is a sort of short length of metal tube that seems to slide over the knurled part, with a tad of clearance.

I stripped back my coax cable & was able to assemble everything okay; I fitted the short length of metal tube / "sleeve" supplied with the connector, over the cable first then slid it back so that it gripped the braid of the coax between itself and the knurled part of the connector.

I found the inner insulation of the coax fitted nicely inside the knurled part, so that it directed the central conductor straight into the pin without it shorting to the outer.

Now having never met this style of connector before.. I've done nothing more.

I have a standard electrician's crimp tool, and the maplin guy told me to use this to crimp it. He didn't say where to crimp it lol.

It seems to me that if I did hit it with the boggo sparkies crimper, it would make a royal mess? crumple everything? short the braid to the knurled part and then short the knurled part to the inner, before metal fatigue just destroyed the whole lot? Might as well ask a lion to bite it?

Do i need some kind of special tool here or should I attempt to solder it, or is it really ok to crimp it with a standard crimper a la 6242Y?
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
The short story is that you have to crimp it exactly the right amount.

Most of these plugs are paired with a very expensive crimp tool which does the *exact* job for (sometimes) exactly one type of connector.

You can try to crimp it with the tool you have, but you have to be careful to get it crimped evenly and not to crush the inner part of the connector.

Often the correct crimper will make a nice even hexagonal crimp, that may be hard to achieve, but you may be lucky enough to get something reasonably functional.

If the connectors are reasonably affordable, and you have the spare cable length, you might be best to be prepared to have a few tries...
 
No special tools needed, just a standard iron?

Sounds good, have to look for these. Let me know if you have a link as to where to order decent ones :)

I can see some on ebay if I search 'sma solder plug' etc, but they look just like the crimp type with a tiny hole drilled in the side of the outer 'clamper' tube.

I'm assuming the idea is to run solder onto the braid beneath the outer tube, by feeding fine flux cored solder wire into the hole whilst heating the outer tube with the iron?

They don't look much like the type posted above & I'm worried they would just melt the inner insulator, risking a short?
 
Last edited:

davenn

Moderator
no special tools and yup just a standard iron

ONLY the centre pin is soldered, the shield is clamped between other parts of the connector
any large electronics supplier should bve able to supply them

Dave
 
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