Clocked Flip Flop 7400 (CB22413E)

This TTL circuit uses 5 NAND gates of 7400 integrated circuits. It must be powered with 5 V.

S meter (2) (CB1440E )
We find this circuit in a radio amateur publication of 1977. Its purpose is to measure the...
Audio Inverter Amplifier (CB12438E)
This inverter amplifier is from a 1992 publication. NPN transistors can be BC548 and PNP BC558....
Timed Courtesy Light (CB10288E)
I found this circuit in a 1986 English magazine. It can still be easily assembled, exchanging Q1...