This amplifier was found in a tube equipment manual from 1947. The high-fidelity circuit has pentode tubes at the output and a source with transformer.
We found in this American documentation this circuit for activating common cathode displays. In it we...
An application for the previous circuit (CB109) is shown here. The central frequency is determined by C and...
Indicated by a Popular Electronics of the 90s originally to measure the light determining the exposure...