This amplifier was found in a 1969 Mullard documentation. The circuit uses transistors that have as modern equivalents the BC548 and BC549.
We can either supply this circuit with 12 V if we use a relay for this voltage as well as 6 V if...
Two NAND gates are used in the configuration shown here to perform as a monostable triggered by...
Frequency and active cycle of this circuit are fixed by the two crystals that may have different...