This 1969 Mullar circuit appears elsewhere on this site. The circuit uses germanium diodes and the indicator is microammeter with zero in the center of the scale.
This oscillator circuit with the TLV2474 was obtained from a Texas Instruments Operational Amplifier...
Datasheet of This amplifier uses a pair of complementary transistors at the output and can provide 1 W of...
Used by the police this receiver tuned to the low VHF band. The circuit is from a documentation from the...