Found in a 1924 documentation, this circuit is powered by 3 batteries, two of which are high voltage. The output is a high impedance headphone jack.
The figure shows how to generate a 60 Hz clock signal for TTL circuits. The circuit is from Radio...
This circuit for an isolated instrument or multimeter can increase the sensitivity of your...
Although it is a common configuration today, this circuit was taken from an old publication. The...