Thanks all. I will check out the NanoVNA. I have a lot of instruments, but no VNA, but I have a HP 1GHz RF signal generator, cannot remember the type offhand and also a HP8116A generator and an Agilent scope.
Thing is that I am trying to build a memory board for a HP1000 A400 and before that I built a 5-slot backplane for the A-series. Now why would anyone want to do that. Well, the 16-slot A400 backplane I have as a flaky PSU and there are no schematics. Further is it LARGE and LOUD, even if I have tuned down the the fans somewhat. The Idea was to build a "mini A400" that would fit in a standard small PC case.?
Core issue seems to be ringing on the lower 10 bits of the address bus. The backplane I built is a four-layer board. I am just curious...
Anders