A Frequency-Stable VHF Oscillator for Low-Voltage Operation
NAVAL RESEARCH LAB WASHINGTON DC
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In compliance with characteristics and specifications set forth by the Bureau of Aeronautics, a frequency-stable VHF oscillator for low-voltage operation has been developed at this Laboratory. As a guide to the final choice, several types of circuits were investigated primarily for their low-voltage operation, without considering too strongly their frequency stabilities. These included a modified-butterfly oscillator a two-wire open-line oscillator a cathode-coupled oscillator a prism cavity oscillator a cathode-coupled prism cavity oscillator a circular cavity oscillator and various models of the cathode-coupled cavity type oscillator. The final cavity type local oscillator is continuously tunable, covers the frequency range 440 to 545 Mc, operates on a nominal anode supply of 28 v, and has a second harmonic of less than 5 percent. The final oscillator, which weighs 2 12 lb, has an inside diameter of 14.6 cm, an inside depth of 4.4 cm, and a wall thickness of 0.63 cm. Temperature control and compensation were determined which should provide a frequency stability of - 0.02 percent with an ambient temperature change of 90 deg C.
- Electrical and Electronic Equipment