Preset Extension For Function Generator

The AF Function Generator de- scribed in Elektor Electronics, December 1984, has generated a lot of interest, which is mainly due to the instrument being versatile, relatively simple to construct, and sufficiently ac- curate for a great many appli- cations. The preset extension proposed here is a separately housed, 10-way programmable ancillary intended to drive the generator"s VCO input. Fre- quencies that are often used for test and measurement pur- poses can be called up at the flick of a switch, and there is also a facility to successively select all ten of them at variable speed, providing a 10-fre- quency sweep function. Fur- thermore, the extension pro- vides an output signal to trigger an oscilloscope with any one of the ten available frequencies. Ease of control is the key word in this design. Once you have set the ten generator output frequencies with the aid of multiturn presets, you can sel- ect manual operation on the ex- tension and press the SINGLE STEP key until th...