This circuit is from an old English publication from 1968. We can implement it with TIP32 transistors in a more modern version. Power can be done with either large batteries or a power supply.
Suggested by an American technical documentation, this circuit is polarized in order to provide an...
This modulated siren was found in the December 1974 issue of Radio Electronics magazine. A higher...
This circuit with 5 times gain was found in European documentation from the 1980s. The input and...