This circuit controls the channel separation as described in the March 1973 Radio Electronis magazine article. The circuit was proposed by Mullard (Philips) and consists of two channels as shown.
The transistors are 2N918, 2N3464 and other RF equivalents of the time for Q1. For Q2, 2N3399, 2N2894...
This LED signaling circuit uses a programmable unijunction transistor (PUT) as a relaxation...
This is a commercial circuit from a Japanese publication from 1972. The circuit uses a FET that...