RE: [SI-LIST] : HF SCSI connectors

Charles Hill (chuckh@csn.net)
Tue, 9 Dec 1997 04:34:30 -0700

Mickey,

I have noticed mini DB-50 connector SCSI cables for sale and my Adaptec =
2940UW board has a 68 pin connector on 0.050 spacing. These are much =
smaller than the larger DB25 connectors used in Apple equipment. Also, =
the DB25 must not have many ground lines.=20

Chuck
chuckh@altaeng.com

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From: mfreed@wlgore.com[SMTP:mfreed@wlgore.com]
Sent: Monday, December 08, 1997 9:57 AM
To: si-list@silab.Eng.Sun.COM
Subject: [SI-LIST] : HF SCSI connectors

Hi,
A brief statement of the obvious: Data rates seem to keep =
increasing.
That's all well and good, it keeps EMI folks employed. The problem I =
have
with it is that when it comes to connector design, connectors such as =
SCSI
an DB-9's aren't designed for Gigabit/sec and higher data rates but =
people
are using them anyway. This makes is a problem when designing a cable
since there is usually a connector at either end. Yes some vendors
incorperate little closely spaced dimples to provide better contact =
between
the header and connector but from some of the testing I've been doing =
I'm
finding that the weak link EMI-wise is header-connector interface as
opposed to the rest of the cable assembly. So the question is has =
anyone
found a vendor out there that's doing anything innovative in the way of
high frequency SCSI or DB-9 connectors.

Mickey Freed
mfreed@wlgore.com