SCR Steady Hand (CB22098E)

This “test your nerves” game was found in old documentation. The SCR can be of any sensitive type, for example series 106.

AC Millivoltmeter (CB4514E)
This alternating voltage voltmeter was found in a 1967 magazine. The magazine no longer exists, but...
Transistorized Voltmeter (CB18582E)
This transistor circuit was only found in documentation from the 1960s. The original transistor is made of...
10-minute timer 555 (CB9368E)
Found in a magazine 73 for radio amateurs, this circuit has two settings, one for the interval and the...