公开(公告)号：CA1170347A

公开(公告)日：1984-07-03

申请号：CA410531

申请日：1982-08-31

Applicant: MOTOROLA INC

Inventor： LOVING ROBERT O JR ,  ZAKRZEWSKI THADDEUS J ,  STEDMAN ROBERT B ,  OSBERG DARYL F

IPC: H05K5/06 ,  H05K9/00

Abstract: A high frequency RF gasket is disclosed which provides an electromagnetic seal between a first and second piece of a shielding enclosure. The gasket comprises highly resilient finger projections which are attached to and project out along the perimeter of the first enclosure piece. The relative mating arrangement of the gasket, and first and second enclosure piece is such that a small force imposed on said first enclosure piece is resisted by a much larger resistance force along the longitudinal dimension of the highly resilient finger projections as the fingers engage the second enclosure piece. The larger resistance force causes sufficiently high pressure at the point of contact between the finger projections and the second enclosure piece so that the surface of the second enclosure piece yields to the finger projections. Thus reliable electrical contact between the first and second enclosure pieces is obtained by piercing the surface of the second enclosure piece with the finger projection's point of contact with the second enclosure piece.

公开(公告)号：CA2007012A1

公开(公告)日：1990-08-14

申请号：CA2007012

申请日：1990-01-03

Applicant: MOTOROLA INC

Inventor： ERICKSON PAUL M ,  MATZ JOHN E ,  GROCH TIM J ,  STEDMAN ROBERT B ,  SHAUGHNESSY MARK L ,  KANDAH TAISIR Y

IPC: H04H20/67

公开(公告)号：CA1076211A

公开(公告)日：1980-04-22

申请号：CA257587

申请日：1976-07-22

Applicant: MOTOROLA INC

Inventor： BESEKE KERMIT M ,  RAMSLAND DAVID G ,  STEDMAN ROBERT B

IPC: H04B3/04 ,  H04B1/10 ,  H04B3/06 ,  H04B7/02 ,  H04B7/08 ,  H04B17/00 ,  H04Q7/22 ,  H04Q7/28 ,  H04Q7/38

Abstract: CM-75583 AN IMPROVED RECEIVER VOTING SYSTEM An improved receiver voting system is disclosed in which the lowest noise audio signal produced by a number of different radio receivers is selected and coupled to a monitoring speaker. Each receiver receives signals from a transmitter and produces either corresponding audio signals or squelch indicating status tones which are then transmitted to a voting (selecting) control center by telephone communication lines. The voting control center then selects the unsquelched receiver audio signal having the lowest noise level and couples this signal to a monitoring speaker. The voting center indicates which receiver is supplying the selected signal and therefore identifies the most favorable receiver to transmitter signal path. Parallel squelch circuits in each receiver provide for the initial selection of the strongest received signal while preventing the existence of an irritating "squelch tail". Automatic gain control circuitry in the voting control center compensates for loss variations between the different transmission lines coupling signals to the voting control center, Status tone decoders in the voting control center prevent the selection of the squelch indicating status tone as the receiver signal having the lowest noise level. The voting control center has circuitry for switching in a status tone notch filter and changing the response time of the status tone decoder whenever a squelch indicating status tone is anticipated by the control center. Each receiver produces an audio pause which precedes the production of a squelch indicating status tone, and this enables the voting control center to anticipate the status tone and to rapidly respond to its occurrence.

公开(公告)号：CA2007012C

公开(公告)日：1993-06-01

申请号：CA2007012

申请日：1990-01-03

Applicant: MOTOROLA INC

Inventor： ERICKSON PAUL M ,  MATZ JOHN E ,  GROCH TIM J ,  STEDMAN ROBERT B ,  SHAUGHNESSY MARK L ,  KANDAH TAISIR Y

IPC: H04H20/67 ,  H04B1/04

Abstract: A simulcast broadcast uses digital signal processing techniques to scale pulse coded modulation samples of a signal for broadcast. Samples are adjusted to fully utilize all quantization levels representable by an 8-bit word. Time delay is adjustable using digital techniques by writing and reading data into and out of a RAM. Signal amplitude is adjustable by multiplying samples by a numeric factor. A computer can be used to adjust processing delay and amplification of the digital signal processor.

公开(公告)号：CA1051094A

公开(公告)日：1979-03-20

申请号：CA262345

申请日：1976-09-30

Applicant: MOTOROLA INC

Inventor： STEDMAN ROBERT B

IPC: H04B1/06 ,  H04B1/10 ,  H04B17/00 ,  H04B1/16

Abstract: SIGNAL QUALITY DETECTOR An FM radio receiver with a discriminator having the output connected to a first bandpass filter, tuned to a frequency above the audio but within the bandpass of the discriminator, and to a second bandpass filter tuned to a frequency above the audio, within the bandpass of the discriminator and adjacent the bandpass of the first filter, with the outputs of the two bandpass filters connected to a selector circuit for selecting, as an indication of the strength of signals being received by the radio receiver, the output having the lowest amplitude signal thereon.