An audio distortion elimination circuit is provided which eliminates the effects of periodic decreases in signal amplitude of an audio signal. A comb filter includes an undelayed signal path, a signal path including a delay line and a combining circuit coupled between a source of audio signals and an audio output circuit. The combining circuit combines the delayed and undelayed audio signals to provide a response for the comb filter which is a function of the delay of the delay line and exhibits...

An apparatus is provided to minimize harmonic distortion in a microwave circuit which is used with a velocity measuring system. The apparatus is particularly applicable where at least two Doppler signals are generated at substantially the same time from two different targets whose velocity is being measured. The apparatus includes a microwave circuit which transmits a microwave energy signal directed to each of the targets. The microwave circuit also receives the signals reflected by the targets...

An a-c linear amplifier with two push-pull-connected output transistors includes an ancillary transistor which, during saturation of one of the output transistors and the simultaneous cutoff of a controlled transistor driving these output transistors through a set of pilot transistors, conducts to maintain the base potential of this controlled transistor at its conduction threshold for preventing a distortion of the end of the flattened peak of the corresponding half-cycle of the output voltage....

A device for maintaining a constant distortion output from a musical instrument amplifier over a volume range of the musical system. The amplifier is set at a predesired volume setting and volume control is provided by a potentiometer control interposed between the output of the amplifier which may, for example, be a guitar amplifier, and the loudspeaker. The potentiometer is connected so that one end is in series with the speaker providing the primary means for controlling volume while the othe...

A test signal composed of two or more harmonically related spectral lines is generated, frequency swept or stepped in fixed phase relationship and transmitted into a device under test. At the output of this device under test, the received signal is suitably amplified, and changes of the signal shape in the time domain are observed. Such changes caused by amplitude or phase misalignments of the device under test are, in turn, evaluated to unveil said misalignments. Various levels of sophisticatio...

A synchronous switched vertical deflection (SSVD) circuit is coupled by a flyback transformer to a horizontal deflection circuit. The SSVD circuit loads the horizontal deflection circuit at a vertical parabolic rate providing East-West pincushion correction. Because of the inductance of the vertical deflection winding, the parabolic loading is asymmetrical, producing a keystone-like raster distortion. A correction circuit, such as a constant current source coupled to the vertical deflection wind...

A distortion circuit includes at least two distortion imparting circuits for respectively imparting different distortion characteristics to an input data, and an adder for adding output data from at least two distortion imparting circuits. When an input data having the required waveform is supplied to each of the distortion imparting circuits, the input data is respectively imparted with different distortion characteristics in each of the distortion imparting circuits. Then, the output signals f...

A distortion compensating device which can significantly remove residual distortion, in which a value of matching circuit 11 is set up so that the distortion generated at a gain controlling unit 9 offsets the distortion remaining in a power amplifier 12. That is, the value of the matching circuit 11 is set up so that the phase of the residual distortion included in the output of the matching circuit 11 is rendered opposite to the phase of the residual distortion included in the output of the pow...

An improved noise loading arrangement and method are disclosed capable of measuring low intensity intermodulaton distortion products, such as introduced in the operation of individual wideband transmission repeaters. The improved arrangement and method also have the further capability of resolving individual orders of distortion products. The arrangement utilizes a noise signal generator that produces a pseudorandom signal made of several spectral components providing high spectral density throu...

Apparatus for testing distortion of an AC power wave and providing an error signal if distortion of the type likely to cause DC output of a power supply receiving the AC power wave to fall below acceptable levels occurs.