This timer, like the previous circuits, uses a currently uncommon integrated circuit. The time is given by capacitor C1 and R2 which has the range of values indicated in the diagram.
This high impedance and low capacitance buffer employs a junction FET that can be BF245 or...
This circuit was found in an American documentation from 1966. The transistors are from that time...
This circuit for the 85 to 95 MHz band has a gain of 15 dB. We find it in a 1980s documentation. The...