This 1950s audio amplifier uses output tubes of type 1625 in its output stage. The Class B circuit provides a few watts of power and uses transformers that are not readily available today.
This notch filter or reject filter rejects signals of a certain frequency with good selectivity. The...
The purpose of this circuit, which we find in a 1975 radio amateur publication, is to measure the...
The coils of this simple mid-wave radius are wound 28 or 26 on a 12 to 30 cm long ferrite rod and the...