This circuit was found in documentation from the 1980s. Transistors are general-purpose types like the BC548 for NPN and the BC558 for PNP.
The S-meter is signal strength meter, coupled to telecommunications receivers to indicate the...
This power supply can be implemented with a TIP32 providing an adjustable output at the 2k2...
This circuit was obtained from a 1967 magazine. The magazine no longer exists, but the circuit can still...