Club Project

Building a logic Probe

In this age of "black boxes" we feel that construction and experimentation are at the heart of amateur radio, and we encourage these whenever possible. This logic probe project is one that was carried out in 1999. This year (2000) we are putting together a morse oscillator and a decoder. One is being prepared by Jeremy Ei5GM and the other by John Ei9ESB.

Under the direction of the late Fred Owens Ei2EG, members of the Club constructed this logic probe. A kit of parts was made up for each member.

On the first night Fred began with the etching of the boards. We did not have too much trouble with this, next came the fitting of the resistors, then capacitors and diodes and LEDs. Finally there was the IC chip base and then the IC itself. The whole project took about three evenings and there was great excitement when the first probe was tried and it worked. With a little bit of persuasion, and checking of solder joints, the others too began to spring into life until in the end all began to work, and Fred pronounced them as passed. (see illustrations below)

Design/ layout was fairly simple: