phone systems, old and less-old

[Jon Elson]

On 09/18/2019 09:23 PM, Fred Cisin via cctalk wrote:
>>> Please don't let anybody call the 25 pair 50-pin 
>>> miniature ribbon
>>> connector (RJ21),  "Centronics"!
>
> On Wed, 18 Sep 2019, Chuck Guzis via cctalk wrote:
>> We used to call them "blue ribbon" connectors.  I'm sure 
>> that that's
>> also a misnomer.
>
> I still believe that that is the correct name.
> I've always assumed that that was Amphenol's name for that 
> line of connector when they invented it.  I also assumed 
> that "blue ribbon" was a reference to the blue first-prize 
> ribbons at county fair type contests.
>
> Although a friend claimed that that name was 
> unintentional, since instead of pins, it uses "ribbon 
> contacts", hence also "micro ribbon connector". and many 
> of them had a BLUE plastic center section.
>
The original Amphenol connector was about 3 X the contact 
spacing of the micro-blue ribbon
connector, but basically the same design.  They used Diallyl 
pthalate insulators.  I don't know if these are just always 
dyed blue, or the chemical makeup makes them blue, but it is 
a deep blue color.  So, that's where the blue in the name 
comes from.  The contacts are punched out of a ribbon of 
gold-plated beryllium copper, so that's where the ribbon in 
the name comes from.

Jon