This 2mA source was found in a 1968’s Philips documentation. The transistor may be the BC549.
This two-transistor circuit was found in Radio Electronics magazine from February 1959. It is...
This 1967 commercial radio covers 6 wave bands selected by appropriate coils. The circuit...
In relation to the previous circuit (CB18493E) this spy has an extra transistor, which can be a...