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.

9 V power supply (CB20222E)
This sophisticated power supply from the 80s uses components from the period, which makes it...
Short Wave Transmitter with Ceramic Filter (CB16788E)
We found this small shortwave transmitter circuit in a 1994 documentation. The frequency of the...
LC Oscillator Shield (CB18930E)
This circuit generates a signal up to a few megahertz depending only on the LC resonant circuit...