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.

Push-pull 3-transistor amplifier (CB18305E)
This amplifier from 100 to 150mW was found in a Japanese documentation from 1967. The circuit uses...
FET RC Oscillator (CB19847E)
This circuit is from a manual of JFETs and can be implemented with the BF245 and for the bipolar...
Stabilized Power Supply (CB13988E)
This source of some amps for voltages up to 40 V was found in an Italian magazine Elettronica...