This circuit was found in a Ferranti documentation from 1969. The transistors are common types of the company at the time. Smaller equivalents may be used. The output power is of the order of 150 mW.
This circuit can generate signals from 80 to 800 Hz with an amplitude of 0.3 V. We find it in a...
We found this circuit in a Hands-On Electroncs from the 90s. The circuit uses an LED indicator. Diodes...
We found this configuration in a documentation for radio amateurs from 1974. The circuit can be...