This 6W amplifier with 4 tubes was indicated in an American documentation from 1947 to operate with recorders. The circuit uses a source with a transformer.
This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit...
This shield was found in the June 1995 Electronics Now magazine. The circuit uses a low-power...
This circuit has a 200 kHz bandwidth and a low input current. The circuit is from the 80's, but...