Connectors: Both contact surfaces must also be the same material?

[Paul Birkel]

-----Original Message-----
From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Jon Elson
Sent: Sunday, July 10, 2016 9:46 PM
To: General at classiccmp.org; Discussion at classiccmp.org:On-Topic and Off-Topic
Posts
Subject: Re: Connectors: Both contact surfaces must also be the same
material?

On 07/10/2016 01:58 PM, Al Kossow wrote:
>
> On 7/10/16 1:14 AM, Paul Birkel wrote:
>
>> Almost every DEC System Unit ("backplane") that I've ever seen uses 
>> tinned-contacts, yet the Modules all use gold-plated fingers.
>>
> I'm not near one right now, but there should be gold plating on the 
> finger in the DEC connector block at the point of contact with the pcb 
> edge connector. It's easier to see on the VAX era blocks.
>
>
Absolutely.  The WW pins were tinned, but there was selective gold plating
on the card edge contact fingers.
It would take a strong light and magnifier to see it down inside the
connector, but you can rest assured the contact was gold-gold.

Jon
-----

Evidently a strong light *and* a strong magnifier (at least for me!).   Off
to find one ... well, two.

paul
-----