Showing papers on "Crystal oven published in 1972"

Adjustable frequency pulse generator

Abstract: In a pulse generator such as may be used in crystal controlled electronic time pieces, comprising an oscillator circuit coupled to a chain of successive frequency divider stages, to obtain output pulses substantially lower in frequency than the oscillator frequency, means are provided to periodically and temporarily bypass one of the frequency divider stages. The frequency correction made by such bypass arrangement may serve to correct for the error in oscillation frequency of a crystal controlling the oscillator circuit when such crystal is purposely ground to oscillate at slightly below a desired precise rate.

Some Experimental Results with an Atomic Hydrogen Storage Beam Frequency Standard

Abstract: A frequency standard is described in which a quartz crystal oscillator is locked to the hydrogen hyperfine transition using the dispersion of this resonance. The hydrogen storage beam apparatus closely resembles a hydrogen maser with a low-Q cavity below oscillation threshold. Cavity pulling can be reduced to a point where environmental temperature fluctuations limit the stability mainly via the second-order Doppler effect. Locking to the dispersion feature of the resonance eliminates the need for frequency modulation in order to find line-center. The stability of the frequency standard was measured against crystal oscillators and cesium beam frequency standards; stabilities of 4 × 10-13 were recorded for sampling times of 30 seconds and of 3 hours.

Active trimming of film deposited oscillators

Abstract: A system for calibrating oscillators by trimming film resistors includes a network for energizing a film oscillator under simulated operating conditions, with a digital counter measuring the frequency of the active oscillator by counting with a zero axis register the number of times the oscillator signal waveform crosses the zero axis of a zero axis detector and thereafter converting to frequency by dividing the resulting count by the count of a simultaneously triggered time register, comparing this measured frequency to a predetermined frequency to be achieved, and physically modifying the film resistor in response to the frequency comparison to correct the frequency of the film oscillator.

Tunable crystal oscillator

Abstract: A tunable crystal oscillator having a crystal operated in series resonance and having an oscillating frequency which is detunable in a given frequency range close to the natural frequency of the crystal by means of at least one variable impedance component. The crystal is connected in series with a first operational amplifier having a feedback branch, the output of the first amplifier being coupled to the input of a second operational amplifier. The output of the second amplifier is connected to that terminal of the crystal which is in opposed connection to the first operational amplifier. The crystal oscillator is arranged to satisfy a Laplace transformed differential equation derived from the network of the crystal oscillator, the two amplifiers and associated circuit components.

Method for obtaining a harmonic frequency using a potassium bromate nonlinear optical component

Abstract: A nonlinear optical component having a single crystal characterized by the single crystal being a trigonal crystal of potassium bromate. The single crystal is a piezo electric crystal with electro-optical properties which is useful in a system for either producing a harmonic frequency of electromagnetic radiation in the infrared, visible and ultraviolet spectral range or modulating a beam of electromagnetic radiation. The crystal is also useful as a piezoelectric device for generating acoustical vibrations, for use as a spark generator, for use as a frequency generator, for use as a frequency stabilizer, and for use as an electrical acoustical transformer and receiver.

Wide-range temperature compensation by addition of two crystal-resonator frequencies: application to quartz and LiTaO3

Abstract: A novel approach to the problem of temperature compensation for crystal oscillators is described with applications to medium- and low-frequency resonators.