Way back in 2000 (this is being written in March 2008) I ran across a neat little continuity tester in issue #1 of the now defunct Homebrewer Magazine.
It was in the Test Topics column written by Joe Everhart, N2CX. Little did I know then that our paths would cross at OzarkCOn 2007.
But thats another story, and a good one too.
In his column Joe discussed a little piezo buzzer for continuity testing and then mentioned this circuit as a "tad more complex
but much more versatile. It's an audio oscillator, puts less than 1 ma through the circuit under test, has plenty of volume, can check not only continuity, but also diodes, electrolytic caps,
and will give some idea of resistance due to changes in the tone pitch.
Check out the enclosure and you'll see why I affectionately refer to this little tester as the Spaghetti Tester. It's beccome one
of the, most used items on the bench. No need to look at digits or needles, just concentrate on placing the probes, and listen for the tone.
The schmatic for this little jewel is here
