This circuit was found in Texas Instruments documentation from 1968. The transistors are from that time, admitting modern equivalents. The response ranges is from 20 to 20 000 Hz.
April 2017 - The kit for STMicroelectronics STM32F7 32-bit microcontrollers is available from...
This traditional unijunction transistor configuration was found in a 1980s documentation. The functions are...
This different configuration for a crystal galena radio or modernized since a diode is used, has a...