We found this circuit in a 1982 documentation. It uses a CA3140 or equivalent operational amplifier and does not require a symmetrical source. The output is 1 Vpp wide.
The scratching noise is quite unpleasant for those who pass the sound of vinyl records to other...
This circuit for common analog telephones was found in March 1982 Radio Electronics magazine. It...
In the figure we have an RF amplifier for tunnel diode. The frequency range will depend on the...