Motorola Corporation

David J Priniski

Rembert R Stokes

Jerry David Meyerhoff

A signal wrap for transducer fault isolation for use in a telephone system providing remote isolation and identification of malfunctions in end-user telephone equipment such as a handset microphone and handset receiver (earpiece speaker) with an associated sound source and sound receiver.

Signal wrap for transducer fault isolation

A pushbutton tunable radio having an integral audio graphic equalizer is disclosed. During a tuning mode of operation for the radio actuation of any of five presettable pushbuttons results in the selection of a predetermined radio channel frequency within the AM or FM band, and a five digit display is provided indicating the selected channel frequency. During an equalizer mode of operation caused by actuation an equalizer mode selecting pushbutton, the radio remains tuned to the previously selected radio channel, but the frequency indicating display is now replaced by an electronic display indicating the relative emphasis of a plurality of subbands for the corresponding audio signals produced in response to the received radio channel. In the equalizer mode, actuation of any of the presettable radio pushbuttons results in selecting a corresponding one of the audio subbands for adjustment of its relative emphasis. The radio includes up and down manual pushbutton switches which provide for tuning the radio in discrete tuning increments in either upward or downward directions during the tuning mode of the radio. During the equalizer mode, after one of the subbands has been selected by actuation of one of the presettable pushbuttons, actuation of the up or down tuning pushbuttons will cause a corresponding upward or downward discrete increment adjustment of the relative emphasis of the selected one of the audio subbands.

Radio with audio graphic equalizer

The antenna of a transceiver couples through a low pass filter to the input port of a high pass filter network. The high pass network is designed to reflect a very high impedance to its input port when its output port is at ground potential. The transmitter portion of the transceiver couples to the input port of the network with the receiver coupling to the network output port. A semiconductor diode couples from the output port to ground potential. In the receive mode the combination low pass and high pass filters couple received signals in the desired frequency band to the input of the receiver. Upon activation to the transmit mode the diode is forward biased whereby the network output port is taken to ground potential. In this mode the filter network effectively isolates the receiver from the transmitter.

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Lake-in-the-Hills, IL, United States of America

David J Priniski