Filter selection circuit with PIN diode (CB20933E)

Found in Popular Electronics from the 1980s, this circuit is intended for switching filters with PIN diodes.

| Clique na imagem para ampliar |

CMOS Oscillator up to 10 MHz (CB13817E)
This circuit uses NOR ports to generate signals up to 10 MHz, depending on the crystal. The supply...
Sound Reinforcer (CB12868E)
The original transistor for this circuit from a 1973 publication is germanium, but a silicon...
People detector (CB22134E)
With this name, the English publication where we found this circuit indicated a sensitive touch...