This QST circuit generates 4 frequency signals according to the crystals used. Transistors admit equivalents although the indicated types can still be found with some ease.
Like the previous circuit, this is used in the analog part of the telephone lines. The same...
This analog TV circuit generates bars in the NTSC standard. We found it in the July 1991 issue of...
This transmitter kicks in when the microphone picks up sound. This sound then modulates the signal...