It's time to restore the 11/45.

Jacob Ritorto jacob.ritorto at gmail.com
Thu Feb 5 15:45:50 CST 2015


excellent information - thanks!

On Thu, Feb 5, 2015 at 4:38 PM, Tothwolf <tothwolf at concentric.net> wrote:

> On Wed, 4 Feb 2015, Jacob Ritorto wrote:
>
>> On Wed, Feb 4, 2015 at 10:00 PM, Jon Elson <elson at pico-systems.com>
>> wrote:
>>
>>>
>>> The 11/45 has a row of little step-down regulator modules, all plugged
>>> in with those horrible AMP Mate-n-Lock connectors.  We often had bad
>>> contacts on those and they would sometimes burn the connector housings or
>>> char the ends of the wires.  That was all about 1980, I can't imagine
>>> they've improved with age.  I think you may have more trouble with these
>>> than anything else in the machine.
>>>
>>
>> I wonder if spraying out with crc contact cleaner and a nice slathering
>> of dielectric grease would help.
>>
>
> Never use silicone (dielectric) grease anywhere near this sort of stuff.
> Western Electric / AT&T learned the hard way back in the day when the stuff
> damaged switch and relay contacts in their telephone switches. On the other
> hand, something like Sanchem A-Special would be fine, although a little
> messy. (And before someone asks, no, A-Special is not anything at all like
> that nasty "Noalox" zinc particle garbage from Ideal Industries...totally
> different product families and applications.)
>
> The main issue with AMP Mate-n-lock connectors (and similar pin and socket
> connectors from Molex) is the use of tin plated spring brass contacts
> instead of tin plated beryllium copper contacts. Spring brass contacts are
> not rated for very much current compared to beryllium copper contacts, but
> manufacturers tend to buy whatever is cheapest. I've successfully used both
> types of contacts for years without issues and haven't (yet) had the
> catastrophic failures some people have described. If I use these type of
> connectors for power though, I use beryllium copper contacts.
>


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