This circuit was obtained from a 1947 amplifier manual. The circuit makes use of a transformer source, but it can also be battery powered.
This circuit is intended for calls to the deaf and is indicated in an old English documentation. LEDs can be...
Suggested by Mullard in a1969 documentation, this circuit generates the erasure signal for tape...
The main feature of this RF oscillator that operates in the range of 100 to 800 kHz is its low...