Automatic switching system for a combination transceiver-auxilliary receiver radio

• US 4,216,432 A
• Filed: 09/08/1977
• Issued: 08/05/1980
• Est. Priority Date: 09/08/1977
• Status: Expired due to Term

• Current Assignee: General Research of Electronics, Inc.
• Original Assignee: General Research of Electronics, Inc.
• Inventors: Imazeki, Kazuyoshi, Kazami, Koichi
• Primary Examiner(s): Martin, John C.
• Assistant Examiner(s): Coles, Edward L.
• Application Number:
  US05/831,421
• Time in Patent Office: 1,062 Days
• Field of Search: 325/21, 325/22, 325/302, 325/303, 325/306, 325/473
• US Class Current: 455/79
• CPC Class Codes: H04B 1/44 Transmit/receive switching

Abstract

In a radio of the type having a selectively operable transmitter portion and an associated receiver portion for two-way communication, such as a CB radio, plus an auxilliary receiver for reproducing auxilliary audio signals, such as an AM/FM radio, a system is provided for automatically interrupting the audio signal output of the auxilliary receiver whenever the transmitter portion is operated. When the transmit/receive switch is in the transmit position, an auxilliary electronic switch interrupts the audio output of the auxilliary receiver by by-passing to ground the audio signal input to the audio amplifier section of the auxilliary receiver.

Claims

1. In a radio of the type having a selectively operable transmitter portion and an associated receiver portion for two-way communication, plus an auxiliary receiver for reproducing auxiliary audio signals, said auxiliary receiver including a tuning section and an audio amplifier section, said tuning section having its output coupled to the input of said audio amplifier section, a system for automatically interrupting the audio signal output of said auxiliary receiver whenever said transmitter portion is operated, said system comprising:

first switch means coupled to said transmitter portion and associated receiver portion for enabling selective activation of said transmitter portion and associated receiver portion;

auxiliary switch means comprising an electronic circuit coupled between said first switch means and said auxiliary receiver, said electronic circuit comprising a switching transistor having its emitter-collector junction coupled in parallel with the input of said audio amplifier section, said switching transistor having its base coupled to said first switch means and responsive to said first switch being operated to activated said transmitter portion for by-passing signals applied to the input of said audio amplifier section from said tuner section, whereby actuation of the switching transistor interrupts the audio reproduction by said auxiliary receiver to prevent the transmitted signal from including the auxiliary audio signal.

2. A system in accordance with claim 1, in which said electronic circuit further includes a driver transistor coupled between said first switch means and said switching transistor, with said driver transistor being biased on when said first switch means activates said associated receiver and being biased off when said first switch means activates said transmitter, and with the collector of said driver transistor being coupled to the base of said switching transistor.