Pc As Tone Generator

36 PC AS TONE GENERATOR J. Schafer DL7PE A GW-BASIC program and a few modifications to the loudspeaker circuit enable any PC, whether an XT, AT or compatible, to function as a precision tone generator with a frequency range of 20 Hz to 120 kHz, with a basic sweep function as a useful option. The nice thing about this generator is that it costs next to nothing, while doubling as a frequency meter. The present PC tone generator, which is really a BASIC program only, is ideal for aligning a wide range of AF circuits. The frequency of the generated tone can be set accurately, so that the low-cost tone gen- erator is suitable for applications that in- clude the tuning of musical instruments (electronic tuning fork), the aligning of RTTY, fax and SSTV filters, and the dimensioning and testing of many other types of tone decoder. In many cases, the BASIC program obviates the use of a func- tion generator and a frequency meter. This is of particular interest for applica- tions in the audi...