This small transmitter appeared in the March 1989 issue of Radio Electronics magazine. The two-transistor circuit used an electret microphone and had a range of a few dozen meters.
This circuit was obtained in an Electronic Design from the 80's. It has the adjustment of the gain...
This circuit was obtained in a 1977 magazine, but it can still be easily assembled, as the...
This circuit uses only passive components and must be tuned to the operating range. The circuit is...