This is a commercial circuit from the year 1958. Transistors are germanium types and transformers and coils are hard to fild today. The circuit is destinated to the reception of medium wave stations.
This circuit is from a 1978 publication. It can be assembled with BC548 transistors for NPN and...
Wired to the output of any amplifier this circuit makes an incandescent lamp flash according the...
Other operational amplifiers in the series, such as the MC34072, MC34074, MC35071, MC35072,...