This circuit of the 70's uses transistors of the time. The circuit can amplify signals from 10 Hz to 100 kHz and modern equivalent components can be used. The circuit is from Ferranti.
This simple AM transmitter for very small ranges uses in the original version of the 1970s, a...
The HA2620 integrated circuit used in this comparator is from the 80's, but the setting can be...
Figure 1 shows a circuit than can be used as time stage in timers, and other applications....