For sale OPT030 board for Agilent / HP 53131 / 53132 (probably some others) frequency counters. I purchased this board three years ago when I was doing my B.sc. in EE. I was creating FPGA based frequency counter as my final project. I had intentions to use MP510 IC from this circuit along with other parts, but I ended up creating a little bit simplier prescaler board for my counter from different parts so this board was never touched, used. It's new. Only upacked to take photo. 

Included is board and RF cable.

Will be carefully packaged and shipped to the buyer within 3 days after purchase. Tracked.