- Published in issue 9/1990 on page 20
LF/HF test probe
For most electronic test and measurement applications, a modern digital multimeter represents excellent value for money. However, in spite of the high input resistance, the accuracy of a DMM degrades rapidly when the frequency of the measured voltage rises above 400 Hz or so. This article describes the basics of designing a passive test probe to overcome this limitation and extend the usable frequency range of a DMM to about 100 MHz.