Looking for a VGA to Sync-on-Green converter

[MicroEngineer]

Anyone know if anything like this is available or am I just wishing. I got a free 21" HP workstation monitor with 3 BNC RGB connectors. Wondering if I can run this as a second monitor on my GF4 Ti4200,

Is it possible? Can it be done? What do I need to make it work?

Any help at all is appreciated

 

[MicroEngineer]

anybody got any ideas?

 

[kranky]

Is it a fixed frequency monitor? That will make things complicated. Read this.

But if it's not fixed frequency, This page indicates that any 3BNC, 4BNC, or 5BNC to VGA cable will work, you would just connect the R, G, B connectors and leave any extra ones unconnected.

This place sells a 5BNC version for $15.
One for $12.