Found in an April 1977 Radio Electronics issue, this circuit uses the well-known XR2206. The C1 values for the various frequency bands are given next to the diagram.
We found this circuit in the Linear Applications Handbook of the National Semiconductor of 1994....
This tone-modulated transmitter was found in recent English documentation. The circuit operates in the 27...
This very low current circuit was found in the April 1995 issue of Electronics Now magazine. The...