Multiband radio receiver with electronic preset tuning system

• US 4,232,395 A
• Filed: 06/20/1978
• Issued: 11/04/1980
• Est. Priority Date: 06/20/1977
• Status: Expired due to Term

• Current Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Original Assignee: Pioneer Electronics (USA) Incorporated (Pioneer Corporation)
• Inventors: Yokogawa, Tomohisa
• Primary Examiner(s): Ng, Jin F.
• Application Number:
  US05/917,227
• Time in Patent Office: 868 Days
• Field of Search: 325/420, 325/421, 325/457, 325/458, 325/464, 325/418, 325/459, 455/175, 455/176, 455/173, 455/180, 455/182, 455/186, 455/197
• US Class Current: 455/173.1
• CPC Class Codes: H03J 5/0263 the digital values being held in an auxiliary non erasable memory

Abstract

A multiband radio receiver having an electronic preset tuning system is provided with a switch which is ganged with a preset switch in the electronic preset tuning system, so that an automatic frequency control is interrupted from a local oscillator in preset operation. During preset operation, no automatic frequency control is provided, as a result of which fine-tuning can be accomplished to memorize a digital signal representative of a completely tuned frequency in a read-write memory.

Claims

1. In a multiband radio receiver having an automatic frequency control signal source, a local oscillator, a reference biasing signal source and a digitally controlled preset tuning system which stores digital values corresponding to preset frequencies in response to the operation of a preset switch, the improvement characterized by an AFC switch normally operating to supply the output of said automatic frequency control signal source to said local oscillator, said AFC switch ganged with said preset switch such that when said preset switch is operated, said AFC switch is switched to supply the output of the said reference biasing signal source to said local oscillator, whereby when said preset switch is operated, said local oscillator provides a signal to said radio receiver under the control of said reference bias potential and at all other times provides a signal to said radio receiver under the control of said automatic frequency control signal source.

2. A multiband radio receiver as defined in claim 1, wherein said preset tuning system comprises an up/down counter whose up/down count is controlled by manual operation;

a digital-to-analog convertor operating to convert the digital count output of said up/down counter into analog signal which is applied, as a tuning voltage, to variable capacitance diodes in a tuning section;

a read-write memory which is addressed by a band selecting switch and channel selecting switches to memorize the digital count output of said up/down counter and to deliver read-out information to said up/down counter; and

a control circuit having inputs connected to said preset switch, said band selecting switch and said channel selecting switches, respectively, a load output connected to said up/down counter and a write output connected to said read-write memory, said control circuit responsive to the information from said preset switch, said band selecting switch and any one of said channel selecting switches to supply a write signal to said read-write memory for memorizing the content of said up/down counter and responsive to the information from said band selecting switch and any one of said channel selecting switches to supply a load signal to said up/down counter for reading out the content of said read-write memory.