In an active equalizer for selectively boosting or attenuating predetermined frequencies of audio or other electrical signals, and which comprises an inverting amplifier having an inverting input which receives the input signal through an input resistance and an output connected with the inverting input through a feedback resistance and at which the equalized output is derived, and an active filter for determining the frequencies to be boosted or attenuated; there is further provided a change-ov...

An adaptive equalizer for a twisted pair telephone line comprises a differential input/output amplifier, with the line connected to its positive input via a resistor and DC blocking capacitors. The junction of these capacitors is grounded via an adjustable impedance. The amplifier has a feedback loop with another adjustable impedance also connected to the negative input of the amplifier. Line impedance variations vary the impedance of both of the adjustable impedances, which, include diodes to s...

An adaptive equalizer is disclosed comprising an amplitude equalizer circuit (12) having an adjustable Q, and a plurality of all-pass circuits (14,15) having adjustable delay bumps. A controller (18) adjusts the tuning, magnitude of the bumps, and the number of all-pass networks in the equalizer in response to variations in the power within a plurality of spectrum samples and the bit error rate of the equalizer output signal.

An equalizer amplifier in which non-linear distortion is substantially eliminated. An input signal is applied to the base of a first transistor the output of which is applied to the base of a second transistor of the opposite conductivity type to the first transistor. Currents are supplied to the first and second transistors in a constant ration. The output from the circuit is provided in response to current flowing in one of the first and second transistors. At least one of the amplifier gain d...

A data signal receiver (100) forms line samples of a received modulated data signal and applies them to a fractionally spaced equalizer (150). The equalizer outputs are demodulated and decisions are formed as to the values of the transmitted data symbols. The equalizer itself is comprised of a plurality of equalizer sections (220, 240, 260, 280) each of which multiplies ones of the line samples with respective ones of a queue of coefficients to form a partial sum. The partial sums are combined t...

Equalizer circuitry for a wideband signal recording/playback system, in particular a home video system, comprises a pre-emphasis and a de-emphasis circuit in the recording channel and the playback channel respectively. In an advantageous embodiment, the pre-emphasis and de-emphasis circuits are of the second-order type. In the preferred embodiment of the circuitry, in each of said channels there is provided a circuit for group-delay equalization, preferably an all-pass filter which comprises at ...

An amplitude equalizer, suitable for use on telephone lines, is disclosed. The circuit includes an adjustable-gain amplifier, and an adjustable-slope equalizer section. A mixer section serves to combine the input signal with a filtered version thereof, in a manner which enables the installer to bring the line of response to specification level at a first predetermined frequency, and then to bring the line to specification level at a second frequency, without disturbing the previously achieved ga...

A load equalizer for attachment to the gooseneck front end of a trailer connected by a fifth wheel hitch on the bed of a towing truck. The structure includes a rigid arm pivotally mounted relative to the trailer. It movably supports a post which engages a pad mounted to the truck bed. The arm and post transfer a portion of the weight of the towed trailer to the truck bed at a location forward of the fifth wheel hitch and truck rear axle so as to balance the respective load carried by the front a...

A line equalizer including a .sqroot.f equalizer for compensating a .sqroot.f-characteristic of a transmission line, a BT equalizer connected in series with the .sqroot.f equalizer for removing an echo component caused by a bridged tap (namely, BT) on the transmission line, and a circuit for controlling the .sqroot.f equalizer is disclosed. A signal applied to the .sqroot.f equalizer is subjected to over-equalization to make the time domain length of impulse response at the output of the .sqroot...

An automatically adjustable equalizer for modifying the spectral contour of digital, analog, and magnetically recorded signals. A temperature sensor-controlled switching circuit automatically adjusts the delay and forward gain parameters of the equalizer so as to optimize the equalization contour, in discrete ranges, over a wide range of temperatures, pressures or other physical processes or conditions.