This circuit has its application suggested in an alarm system. The circuit is from an old RCA manual. R1 has 5.6 ohm, R2 22k, R3 2k2. The capacitor is 8 uF.
September 2017 - Microchip's MCP6411 operational amplifiers for frequencies up to 1 MHz are in...
We found this circuit in a 70s publication. Transistors are general-purpose types of the time. The...
This receiver circuit was found in a Hands On Electronics from the 90s. The circuit uses a PLL...