Mini Megaphone (CB8952E)

Found in Popular Electronics' 90s, this small megaphone is based on LM386. The circuit uses a high impedance microphone.

Power Grid Interference Filter (CB11896E)
This filter is inserted between the interfering device and the interfering device. The coils are...
T521 High Voltage Polymer Capacitors
June 2017 - Kemet T521's new high voltage capacitors with capacitances up to 330 uF and voltages...
1 kHz Astable 4001 (CB24339E)
We found this circuit in the November 1974 Radio Electronics magazine. The frequency depends on C1...