On Mar 31, 2004, at 11:51 PM, Ian White, G3SEK wrote:
Steve Thompson wrote:
Possibly because regular soldering can melt under the heat of the
circulating tank circuit current. A mechanical connection is better
for this area, there
is nothing that can melt. I HAVE SEEN IT HAPPEN MORE THAN ONCE!
In all the high reliability areas I've worked connectors are always
crimped, not soldered - maybe for different reasons from the Heath
amp, but I think many people are not aware of how good a properly
made crimp connection is.
The UK mains wiring regulations are very strict about the quality of
connections in locations where routine inspection will never be
possible after installation (eg buried in walls). Properly made crimp
connections are one of the few categories that they will accept. They
will not accept connections that rely only or mainly on solder, not
anywhere in the system.
The main problem with ordinary solder is the lead. Lead/tin solder
is not strong and it can corrode. However, silver/tin solder is strong
as well as corrosion resistant. Crimp connections are not without
problems - especially if dissimilar metals contact each other (which
creates electrolysis) -- such as copper-wire crimped against a
tin-plated crimp-connector. This is a common problem in amateur
transceivers. The fix is to either solder the crimps to the wires, or
apply silver-conductive paint to the junction.
A big proviso - the wire and crimp tool have to be the right ones for
the connector.
The simple pliers-type crimp tools obviously don't qualify - and
neither do regular pliers, of course - but real ratchet crimp tools
have recently become much cheaper. Prices in the UK have come down to
the equivalent of about $20-25 (www.cpc.co.uk) and presumably the same
far eastern imports could be available in the USA.
That's real progress - so now I won't need to borrow Steve's any more
:-)
--
73 from Ian G3SEK 'In Practice' columnist for RadCom (RSGB)
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Rich Measures, AG6K, 805.386.3734. www.somis.org/
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