Capacitor plague? Inside an HP 8620C sweep oscillator and HP 86245A RF plugin

A teardown of the HP 8620C and HP 86245A by Kerry Wong: I just picked up an HP 8620C sweep oscillator with an HP 86245A 5.9 GHz to 12.4 GHz RF plugin on eBay. This time around though, the unit does not work. While it was advertised as a working unit I could not get […]

DIY HP/Agilent 53131A 010 high stability timebase option

Gerry Sweeney wrote a post on his blog detailing his DIY HP/Agilent 53131A 010 high stability timebase option: I decided to make a clone 010 option board for my counter using a second-hand OCXO bought from e-bay. I designed a PCB to get a professional finish as well as a reliable upgrade for my counter. The main […]

HP 5328A universal frequency counter teardown

Kenneth scored two HP universal frequency counters and popped them open. One generates the timebase from an uncompensated oscillator in a TO-5 package, while the other uses a large temperature controlled oven oscillator: here is both of my counters measuring the same 1pps  taken from my AdaFruit GPS receiver.  The lower one with the  oven-compensated […]

Interfacing Arduino with an HP LED display from the ’70s

John demonstrates how to interface a vintage LED display with the Arduino. The display in question is a HP 5082-745 model, found in calculators, and other products from this manufacturer in the ’70s. Using the display is very easy – kudos to the engineers at HP for making a simple design that could be reusable […]