Well you must connect ground to the shielding, or you will get a ton of noise in the cable.Even with crt I am not quite sure it's good to connect shielding to pin 18 (ground) on the cable side
I have short experience with this cable that I'd like to share, not concerning OSSC, or your specific setup but in general... be careful on what is thrown through HD15... I have just removed it from my setup last week because it caused a problem with my 20F1E with some games on specific colors on specific screens (super mario bros blue sky, 3do usb menu... they were turning yellow).If you have a PVM you should also have BNC connectors.
With the HD15 adapter installed you can simply use a VGA to BNC cable like this...
You will leave the 5th BNC (Vsync if this was truly VGA) disconnected.
HAS outputs composite sync on pin#13 only (Hsync if this was VGA) the 4th BNC.
Don't mess around with SCART if its not directly used by your display.
Well you must connect ground to the shielding, or you will get a ton of noise in the cable.Also if you probe the OSSC with a multimeter in continuity mode you'll see internally all the grounds are connected/bridged anyway.Even with crt I am not quite sure it's good to connect shielding to pin 18 (ground) on the cable side