HP8116A Pulse/Function Generator

HP8116A Pulse/Function Generator
(click images to enlarge)

In 1983, HP introduced a new range of HPIB programmable pulse/function generators that had been developed by HP's German engineers in Böblingen. Model 8116A was the 50 MHz pulse/function generator.

In the 811x series, HP used custom-developed bipolar analog ICs for signal generation and shaping, which basically all happened in analog circuits controlled by a processor through a number of D/A converters. All parameters including rise and fall times are programmable via the HPIB, and some can also be controlled via a control voltage through a front panel input, e.g. 0–10 V → 0–100% pulse width. Because of the analog signal generation, however, timings are not as precise as one might expect (think R/C circuits, not crystals).

The manuals for the 8116A, like so many others, can be downloaded from Didier's Site (KO4BB) (Thanks!)  There is also a nice description of the unit (in German) at amplifier.cd which shows some of the waveforms that can be obtained.

The 8116A is a nice, compact unit, which means that since it is built with 1980s technology, the interior is rather packed. The base board contains signal generation and output stages, the middle board is essentially a multi-channel D/A, and the top board contains the CPU, display/keyboard control, and HPIB interface. The boards are interconnected through ribbon cables. For troubleshooting and calibration, the middle and top boards can be placed upright.

Boards in service position

Base board. The packages with cooling fins are the custom analog function chips.

Control board with D/A converters