This circuit was obtained from HAM Radio magazine in an 80's issue. The FETs are types of the time and the frequency is determined by the crystal. The circuit operates at voltages from 3 to 9 V.
Who is the fastest? This circuit with neon lamp is powered directly by the network (there is no...
I found this circuit on a December 1976 Radio Elettronica. The Italian magazine no longer exists, but...
Some old multimeters have a high resistance scale including an internal circuit powered by a 22.5...