This traditional signal injector configuration was obtained in a 1977 amateur radio manual. The frequency is given by the capacitors and the supply can be made with 1.5 or 3 V.
I found this circuit in a 1992 Electronics Experimenter Handbook. The circuit can be easily...
This automatic switch for multiple loads was shown in the May 1983 issue of Radio Electronics...
The Variable Frequency Oscillator (VFO) shown in the figure can generate signals in a frequency...