Found in an 1868 Mullard documentation this circuit has a dynamic range of 10 Hz to 25,000 Hz. Modern equivalent transistors can be used.
This is the receiver for the previous circuit transmitter. Similarly, no information about the...
This tuning-free circuit was found in an old operating amplifier manual. The setting can serve as...
This grounding test circuit was found in an American 80's documentation. The circuit is for the...