This circuit was found in an English magazine from 1977. Signal inputs and outputs must be shielded, and the circuit can be powered by battery, since its consumption is low.
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...