Found in American documentation from the 1990s, this circuit generates a whistling sound when applied to an amplifier. The power supply must be symmetrical.
This rapid response amplifier uses an integrated one that is not common today but can be...
The sensor in this circuit is a BA315 diode. Other diodes can be experimented, but this is one...
This circuit can be used in PLL, frequency synthesizer in FM and VHF receivers, reducing a...