Abstract: A pitot tube having a series of pressure sensing ports on the upstream side of the tube and a second series of pressure sensing openings on the downstream side of the tube. A longitudinal internal wall in the tube forms a pair of chambers, one of which communicates with the upstream ports and the second which communicates with the downstream ports. A plate attached to the end of the tube has diverging passages communicating with the two chambers, the plate forming a flange for connecting a manifold, a transmitter for indicating the flow pressures sensed by the ports, a gauge or the like.

Abstract: Speech synthesizing apparatus is provided in which different sounds are required for a plurality of channels. The channels are polled in turn on a cyclic scanning basis, the scan for each channel occupying a channel sampling period during which an instantaneous value is generated for the amplitude of a voiced sound component. Values representing instantaneous amplitudes of each of a plurality of unvoiced sounds are separately generated in turn during the period occupied by the scanning of all the channels and these values are stored. A selected one of the unvoiced sound values is extracted from the store as required for a particular channel during the sampling period for that channel, so that an updated value for the unvoiced sound is available on each occasion that that particular channel is sampled. The voiced and unvoiced sound values are then combined during the appropriate sampling periods. The required sound combinations are specified by parameters expressed in digital form for each channel separately.

Abstract: Speech synthesizing apparatus is provided using digital coded values specifying parameters of a sound to be reproduced. The apparatus has a voiced sound generator using digital values specified by input parameters to represent three formant waveforms respectively which are sampled at substantially constant intervals, the parameters each expressing in relation to the sampling interval the frequency of the formant concerned. At each sampling, the input parameters are arranged to derive for each formant waveform respectively a value representative of the instantaneous amplitude of that waveform in relation to the others, the three values obtained then being combined to produce a resultant value representing an instantaneous amplitude output of a voiced sound component waveform. This output waveform is subjected to modification by attenuation and the addition, if required, of an unvoiced sound component before being passed through an analogue converter to a sound reproducing transducer.

Abstract: An improved wideband phase modulator suitable as a simple modulation interface for existing phase modulated transmitters. The disclosed modulator arrangement utilizes a high stability reference oscillator and an associated phase locked loop for optimum long term stability. Means are included for extended phase range and high fidelity of modulation irrespective of loop bandwidth. Both tone and digital modulation is accommodated.