This amplifier with the EL84 tube is a European commercial type from Corpim mounted on a printed circuit board. The diagram appeared in a September 1958 Radio Electronics magazine.
This VCO makes use of an RC4558 which is an operational amplifier with characteristics close to...
In the figure we have a symmetrical power supply stabilized by a zener diode. Transformer and...
The crystal used in this oscillator can have frequencies up to 30 MHz or more, depending on the...