[ Tuesday, January 11, 2000 ] Andy Poling wrote:
> On Tue, 11 Jan 2000, Gregory Leblanc wrote:
> > If you cut the cable
> > lengthwise (no, don't cut the wires) between wires (don't break the
> > insulation on the wires themselves, just the connecting plastic) you can
> > get your cables to be 1/4 the normal width (up until you get to the
> > connector).
>
> I don't know about IDE, but I'm pretty sure that's a big no-no for SCSI
> cables. The alternating conductors in the ribbon cable are sig, gnd, sig,
> gnd, sig, etc. And it's electrically important (for proper impedance and
> noise and cross-talk rejection) that they stay that way.
>
> I think the same is probably true for the schmancy UDMA66 cables too...
So just check with a cable spec and make sure you're not separating a
data signal from its ground return path. Throw some mag rings around
the thing if you want, but since we're (hopefully) terminated properly
(no reflection) the crosstalk issues aren't huge... they suffer more
through the LC matrix of connector adaptors than this split would cause :)
James
--
Miscellaneous Engineer --- IBM Netfinity Performance Development
