On 6/8/23 11:06, Jonathan Stone via cctalk wrote:
On Thursday, June 8, 2023 at 05:20:28 AM PDT, Santo Nucifora via
cctalk<cctalk@classiccmp.org> wrote:
I bought mine from this ebay auction:https://www.ebay.com/itm/171649843131
Specifically, the "D-SUB 3W3 Male" item.
[...]
Note these are 50 Ohm impedance. I always assumed the OEM originals were 75 Ohm.
I've not been able to find 75 Ohm equivalents in the past 3 years I've been
looking.
OTOH I'm not a hardware person, I have no idea if a ~1.5cm-long connector
matters, especially if it's connected to a non-coaxial VGA cable, then to the
VGA input of a multi-sync flat panel display. (I'm not sufficiently retro to
want to go back to carrying 19in sync-on-green CRTs)
A 1.5" long pigtail of the wrong impedance would have very
little effect if the pixel clock is under 100 MHz. A 2 M
long VGA cable with a bunch of wires in a shield DEFINITELY
causes visible artifacts on a mid-frequency VGA. A long
time ago I actually had to make my own VGA cables with HD15
connectors and RG-178 cable, because stock cables were total
crap!
Jon
