This active tone control circuit was found in American documentation from the 90's. The transistor can be general purpose or low noise with high gain.
This Wheatstone bridge has a thermistor or NTC sensor, allowing the measurement of temperatures by...
As we have explored on this site many times, a 2N3055 without the cover works like a low yield...
We found this simple continuity tester in a 1995 documentation. It uses two LEDs to indicate...