[Amps] SB-221 Why is the the variable load capacitor only crimpedto the ...

[rlm]

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=20=

>> crimped, not soldered - maybe for different reasons from the Heath=20
>> amp, but I think many people are not aware of how good a properly=20
>> made crimp connection is.
>
> The UK mains wiring regulations are very strict about the quality of=20=

> connections in locations where routine inspection will never be=20
> possible after installation (eg buried in walls). Properly made crimp=20=

> connections are one of the few categories that they will accept. They=20=

> will not accept connections that rely only or mainly on solder, not=20
> anywhere in the system.

=F0  The main problem with ordinary solder is the lead.  Lead/tin solder=20=

is not strong and it can corrode.  However, silver/tin solder is strong=20=

as well as corrosion resistant.  Crimp connections are not without=20
problems - especially if dissimilar metals contact each other (which=20
creates electrolysis) -- such as copper-wire crimped against a=20
tin-plated crimp-connector.  This is a common problem in amateur=20
transceivers.  The fix is to either solder the crimps to the wires, or=20=

apply silver-conductive paint to the junction.
>
>> A big proviso - the wire and crimp tool have to be the right ones for=20=

>> the connector.
>>
> The simple pliers-type crimp tools obviously don't qualify - and=20
> neither do regular pliers, of course - but real ratchet crimp tools=20
> have recently become much cheaper. Prices in the UK have come down to=20=

> the equivalent of about $20-25 (www.cpc.co.uk) and presumably the same=20=

> 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=20=

> :-)
>
>
> --=20
> 73 from Ian G3SEK         'In Practice' columnist for RadCom (RSGB)
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>
Rich Measures, AG6K, 805.386.3734.  www.somis.org/