Abstract: A single Colpitts-type oscillator has a plurality (here, three) of optional inputs, each having a separate oscillating circuit individually associated therewith. By suitably applying a potential to a selected one of the oscillating circuits, the oscillator may be made to produce one of a plurality of predetermined carrier wave frequencies. The inventive circuit configuration eliminates large volume components such as coupling capacitors and enables hybrid IC construction, which miniaturizes the circuit. The circuit is particularly useful in walkie-talkie FM transceivers.

Abstract: A control voltage for a crystal oscillation circuit is formed by adding two separately generated voltages. One of these voltages is proportionally variable with changes of temperature. The other voltage generally follows the temperature-frequency slope characteristic of the crystal unit. A use of such a control voltage eliminates the requirement for designing specific voltage generator circuits for each respective type of crystal oscillator, thereby enabling a substantial reduction in the cost of manufacture.