Found in a 90s Popular Electronics, this transistorized circuit generates pulses from 2 Hz to 50 kHz in three selectable ranges. The circuit has both AC and DC outputs.
Today we have more compact solutions. This is from a Radio Electronics magazine from October 1990....
This filter was found in Texas Instruments documentation from the 1980s. The circuit uses a common...
16 commercial test circuit for tubes and transistors appeared in Radio Electronics magazine in...