Infrared modulated transmitter (CB7247E)

This simple Philips circuit from the 1960s can use any general-purpose transistor. The signal is modulated at 2.7 kHz.

Delayed pulse generator (CB8523E)
Found in 90's Electronic Engineering, this circuit produces a pulse with a delay that depends on R3...
Voltage Controlled Amplifier (CB24873E)
This circuit was found in the December 1984 issue of Radio Electronics magazine. The circuit has a...
Video preamplifier (CB8741E)
Found in 90s Radio Electronics, this circuit is intended for amplifying analog video signals....