This circuit for the 3 to 6 MHz band was found in a 90s Popular Electronics. The components of the network formed by C6 depend on the frequency range to be covered.
This circuit of a voice-controlled switch, Vox or sonic switch was obtained in a Popular...
This circuit appeared in the July 1969 issue of Radio Electronics magazine. The sensor is an LDR....
This circuit of two transistors was found in a Japanese magazine in 1967. The transistors are made...