That VAXStation4000vlc 3W3 video connector

Doug Jackson doug at
Tue May 4 00:50:29 CDT 2021

HI Paul,

"I don't know what "HD BNC" means.  There's only one BNC"

Years ago when working in a university with Photomultiplier tubes, we used
HV BNC connectors - these looked like standard BNC, but were rated at 10kv.

We also used to use 75 Ohm BNC connectors for video systems.

It is worth noting that there are multiple BNC connectors.

Kindest regards,

Doug Jackson

em: doug at
ph: 0414 986878

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On Tue, 4 May 2021 at 15:30, Paul Koning via cctalk <cctalk at>

> I don't know what "HD BNC" means.  There's only one BNC.  By 3W3 do you
> mean the D-sub shell with 3 coax inserts?  Those are standard items, you
> could just buy one.  The only problem you might encounter is that the cable
> connector kind is probably crimped, and the crimp tooling is likely
> expensive.  But a solder or PC mount connector could be used, with an
> impedance bump that can be ignored for video applications.
> Sync on green is the usual from DEC.
>         paul
> > On May 3, 2021, at 7:22 PM, Adam Thornton via cctech <
> cctech at> wrote:
> >
> > I assume it would be way too much to hope that HD BNC would fit it?  Does
> > anyone have a pointer to the actual physical dimensions of the itty-bitty
> > BNC-ish connector in the video port of the VAXStation4000vlc?  If I can
> get
> > red, green, and blue out (assuming since there are only 3 connectors it's
> > sync-on-green) I can put together a sync splitter and turn it into VGA.
> I
> > have at least one decent multisync VGA monitor still, although none with
> > the RGB BNC inputs.
> >
> > Adam

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