Re: Looking for comments on the 15-pin ethernet connector


Dan V. Wilson (thumper!dvw@faline.bellcore.com)
17 Jun 88 17:41:56 GMT


In article <22108@amdcad.AMD.COM>, >, phil@amdcad.UUCP writes:

> Well, if you don't care why should they care? If you care, let them
> know. Make a case out of it with your salesman. Tell people like Sun
> that they should follow the ISO 802.3 international standard for
> transceiver cable connectors and mount them on the OUTSIDE of the
> panel. Like DEC does. Many people do not realize how important this
> is. Many people have not looked at the connection system carefully.
>
> --
>
> I speak for myself, not the company.
> Phil Ngai, {ucbvax,decwrl,allegra}!amdcad!phil or phil@amd.com

Phil is absolutely right. My experience with the DB-15 connectors and the
<insert expletives> slide locks is that they work fine IF the slide is
mounted directly on the connector body (are you listening, Sun?) AND the
connector is mounted on the outside of the panel AND the posts are the
proper height AND the slide hasn't been strained or bent AND the phase of
the moon and several other planets is correct.

My favorite fix is to make a short stub cable out of DB-15 crimp on
connectors and a few inches of 15 conductor flat cable, and to insert this
short cable between the tranceiver cable and the piece of equipment. I've
found that this has eliminated problems with the transceiver cable
connections on Sun 3/75's and 3/160's, which are notorious for having a
thick panel between the connector and slide lock on the Ethernet connection.
I know, I know, the stub cable probably radiates, but I don't care. I've
found that the friction grip from the crimp-on connectors is usually better
than that provided from the connector plus slide lock.

One should note that Sun may use lots of DB-series connectors, but they DO
NOT use slide locks to my knowledge other than on Ethernet connectors. They
always use another type of lock, either the 'wings' (can't think of a better
term), or screws.

I find myself wishing that I believed in Hell just so I could hope the
designer of the slide lock and the connector engineer at Sun could roast
there. Honorable mention should probably go to the writers of the two
original Ethernet specifications for not specifying the transceiver
connectors more fully.

                                        Dan Wilson
                                        dvw@bellcore.com
                                        bellcore!dvw



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