Based on an LM36000 OTA this circuit was found in the July 1988 issue of Radio Electronics magazine. It covers frequencies in the range of 45 Hz to 45 kHz.
The figure shows how to connect a relay to obtain the latch effect. The circuit is from an...
This oscillator with crystal for overtone operation was found in an old American documentation. The coil...
Obtained in a 90s Radio Electronics, this configuration appears with variations in other points of...