Dan,
Do the electronic components on your board make it incompatible to extend the 5000 series mainframe scopes? I see that pads 3 & 4 are ganged together. Does that also make it incompatible?
I've got a 5CT1N curve tracer that I need to work on with my 5440 and would love to use your extender as long as it does melt it. Pin 1A has 200v on the mainframe.
Thanks, Rick