Found in documentation from the 1990s, it uses a sound effects integrated circuit, the SN7677 from Texas Instruments. Unusual component these days.
We found this circuit in the Radio Electronics magazine of May 1977. The circuit has the frequency...
This 200 kHz oscillator was found on a 90's EDN. It consumes only 2.8 mW and has CMOS compatible...
This tracker for audio and RF signals was found in old American documentation. Transistors and...