Applications: Troubleshooting with oscillographs: Classic in concept, the light-beam recording oscillograph preserves multichannel data for detailed examination

What's the most often used, most cost-effective piece of electronic test gear? Ask any veteran of hardware design, and chances are the oscilloscope gets the cigar every time. The scope's reputation as a troubleshooting tool has evolved to where no self-respecting electronics engineer would be without one. Today's high digital data rates and analog working frequencies only enhance the oscilloscope's importance because it is the one device that allows waveshape observation in “real time.” But popularity aside, the standard oscilloscope does have some important, and often overlooked, limitations — limitations not shared by modern versions of the oscilloscope's predecessor, the light-beam recording oscillograph. Although they look (and operate) much like strip chart recorders, oscillographs have much wider bandwidths. Their low-mass galvanometers make real-time hard copy at 10 kHz practical, while strip charts commonly conk out below 100 Hz.