This two-tube circuit, one being a double, was found in Radio Electronics magazine from July 1958. The distance to the microphone depends on noise and losses. The cable must be shielded.
This circuit was found in Motorola's Linear Interface ICs of 1993. The integrated circuit used is not...
Using Linear Technology's LTC4252-1, this circuit was found in a 2005 manual. The circuit makes use of...
The frequency of this oscillator depends on R and C (see math section for electronics). The...