US 4,063,179 AGranted

Channel selector for a scanning monitor receiver

AssigneeCraig Corporation

InventorMarshall M. Brown

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Abstract

A radio broadcast receiver is disclosed for sequentially scanning and monitoring a plurality of preselected broadcast channels to determine the presence of a radio signal in any one of the preselected broadcast channels. Selector means are provided for each preselected channel to enable the user to individually select the mode of operation for each preselected channel. Three modes of operation are provided for each channel as follows: (1) the scan mode; (2) the bypass mode; and (3) the select mode. Structurally, the receiver comprises a two pole, three-position switch associated with each channel. With the switches in their "scan" position, the receiver automatically scans each channel in sequence, stopping only on a channel which is broadcasting, and resumes scanning when such station terminates broadcasting. If any switch is moved to a second "bypass" position, the scanning proceeds as above but without stopping on the bypassed channel. The third position, called the "select" position, permits selection of a subgroup of one or more channels to be scanned. A principal advantage of this arrangement is that automatic scanning can be provided between any selected channels by a positive selection process. The user need not work backward to achieve the same result, that is, by bypassing all channels he wished not to scan. In addition, this radio receiver includes a scanning speed control circuit for adjusting the speed of the scanner according to the mode of operation of each channel. Thus, when a preselected channel is encountered with its selector switch positioned in an unused mode, that is either the bypass mode or the non-select mode when another switch is in the select mode, the speed of the scanning is increased to effectively eliminate the scanning period.

In a radio broadcast receiver for automatically monitoring a plurality of preselected broadcast channels, said receiver comprising a plurality of tuning means for enabling said receiver to receive a preselected plurality of broadcast channels, scanning means connected to said tuning means for sequentially scanning said plurality of tuning means to determine whether a ratio signal is present in any of said plurality of preselected channels, locking means connected to said scanning means for stopping the sequential scanning, said locking means being responsive to the presence of a radio signal in a particular preselected channel for locking said scanning means on said particular preselected channel for the length of transmission, said scanning means automatically recommencing sequential scanning upon termination of said transmission, the improvement comprising:

a plurality of select gate means connected between said scanning means and each of said plurality of tuning means for controlling the activation of each of said tuning means in response to the sequential scanning of said scanning means;
and
a plurality of three-position switches, one of which is connected to each of said select gate means in each of the preselected broadcast channels, whereby the operation of each of said select gate means is controlled by the position of the three-position switch connected thereto, said switches being positionable to select one of the following three modes of operation for said select gate means with respect to each of said preselected channels:
a. a select mode wherein a subgroup of one or more of the preselected channels is selected for scanning, said select mode being represented by a first contact position in each of said switches;
b. a normal scan mode wherein all the preselected channels are scanned, said scan mode being represented by a second contact position in each of said switches;
and
c. a bypass mode wherein a subgroup of one or more of the preselected channels may be bypassed during sequential scanning, said bypass mode being represented by a third contact position in each of said switches.

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Abstract

Claims10