I have an HP 546xx series oscilliscope, and I'd like to buy a used interface module for it. These are the modules that plug onto the back of the scope. I'd prefer one with a serial port, but the GPIB one would be OK. The models I could use are:
54651A serial 54658A serial
54652B serial/parallel 54659B serial/parallel
54650A GPIB 54657A GPIB
Google turns up a lot of test equipment resellers that want seemingly excessive prices for these things (in most cases, more than HP's new prices).
If anyone has an interface module for sale, or can offer me a lead, I'd greatly appreciate it.
Eric