Abstract: In a magnetron a spinner (22), rotatable on a longitudinal axis (x) has a number of evenly spaced markings formed circumferentially on an exterior surface. The markings are sensed, as the spinner rotates, by a photo sensitive transistor (PT) coupled to window (26) in the vacuum envelope of the magnetron by a fiber optic pipe (FP1). The periodicity of pulses, generated by the transistor in response to movement of markings past the window, is divided in a network (43) to generate a succession of further pulses. The further pulses are then counted in circuit (44) and the instantaneous count compared with reference frequency values stored in memory (46) to generate an output signal O/P(1) related to the instantaneous magnetron frequency.

Abstract: An oscillator and mixer circuit of an integrated UHF/VHF modulator circuit includes a single active oscillator circuit to be connected to frequency-determining passive circuits for UHF and multichannel VHF operation, a single mixer part mixing an oscillator signal from the active oscillator circuit with a useful signal, and a reaction-free coupling connected between the single active oscillator circuit and the single mixer part.

Abstract: A balanced LC oscillator for providing differential oscillator output signals includes a pair of transistors the emitters of which are connected to a voltage reference source that provides a fixed voltage thereto. The base electrodes of each transistor is cross coupled to the collector of the other transistor. The LC tank circuit is connected between the collectors of the two transistors and current supply is provided thereto. Although the potential at the bases of the two transistors vary with respect to the oscillator signal appearing thereat, the emitters are held at a fixed potential to eliminate any common mode signal that may otherwise be generated if the potential at the emitters was permitted to vary.

Abstract: Apparatus for receiving electromagnetic radiation at various angles of incidence including an optical element for guiding the radiation upon a radiation detector, and magnetic drive means for adjusting the position of the optical element, characterized by the provision of a shock-resistant suspension for the magnet in the form of a plurality of linear elements in the form of coplanar taut wires or resilient bands that extend radially outwardly from and coplanar with the magnet, together with a plurality of stationary coils arranged circumferentially about the magnet, whereby the magnet can be pivoted about pivot axes, respectively, contained in the plane, and also be displaced in a direction normal to the plane (i.e., in the Z-direction).

Abstract: A signal generator which can inject an optical signal into all the fibers of a cable, and so be left unmanned during jointing operations, uses a tungsten-halogen or other incandescent light source. This is collimated by conventional optical elements and pulsed by a mechanical chopper. All the fiber ends are aligned with and positioned within the chopped collimated beam.

Abstract: A laser recording apparatus for optically recording information on a medium. A laser radiates a beam through an off-center lens. The lens deflects and focusses the beam onto a recording medium at a slight angle. The reflected beam returns through the lens on the opposite side of the optic axis from the incident beam. A mirror in the optical path directs the beam to a photodetector. The apparatus has broadband capabilities and is particularly useful at eliminating unwanted optical feedback when recording onto media having a birefringent protecting layer. Recording errors due to dirt and scratches may be detected by a second embodiment that has two lasers emitting light of different frequencies which upon reflection are detected and compared.

Abstract: Modulation of a carrier signal using both amplitude and angle modulation increases the information capacity of transmission without increasing bandwidth. Complex zeros in an amplitude modulating signal are detected and a conjugation function dependent on the time of occurrence and imaginary root values of the zeros is generated. The conjugation function is inverted or not inverted in accordance with a binary data signal and used to control the frequency of an oscillator whose output is an angle modulated carrier signal which is then amplitude modulated. On reception the amplitude modulating signal is recovered by an envelope detector and the data signal by a phase locked loop.

Abstract: The invention relates to a quartz oscillator comprising two transistors to whose base terminals the collector voltage of each one of the other transistors is applied, a two-terminal network incorporating a quartz resonator being connected to the emitter of one of the transistors. The collector voltage is applied to the corresponding base via a semiconductor junction. The oscillator further includes respective emitter and collector impedances for the transistors in which the product of the emitter impedances is greater than the product of the collector impedances. When the supply voltage is sufficiently low so that the collector-base diodes of the transistors are always in the non-conducting state, the oscillator frequency is independent, to a very large degree, of saturation phenomena of the two transistors. When manufactured in integrated circuit form, only one additional exterior terminal is required for the connection of a quartz resonator.