Radio transmitting and receiving apparatus

• US 4,549,309 A
• Filed: 10/18/1983
• Issued: 10/22/1985
• Est. Priority Date: 08/28/1980
• Status: Expired due to Term

• Current Assignee: Nigel M. Corrigan
• Original Assignee: Nigel M. Corrigan
• Inventors: Corrigan, Nigel M.
• Primary Examiner(s): Bookbinder, Marc E.
• Application Number:
  US06/545,611
• Time in Patent Office: 735 Days
• Field of Search: 455/58, 455/78, 455/79, 455/82, 455/83, 455/98, 370/31, 370/32
• US Class Current: 455/78
• CPC Class Codes: H04B 1/44 Transmit/receive switching

Abstract

A simplex radio transmitting and receiving apparatus, has a transmission blocking means which prevents selection of the transmitting mode of the apparatus if a signal of predetermined strength is being received by the apparatus at the time the press-to-talk key is operated. An over-ride circuit enables the blocking means to be disabled in an emergency or if another transmitter has been left operating in error. The over-ride circuit can be activated by, for example, repeated operation of the press-to-talk key, and ceases to operate when the key is released to return the apparatus to its receiving mode. Also disclosed is a transmission control means which can be used to modify existing transceivers to operate in accordance with the invention. In a further feature of the invention, means are provided to detect the higher power consumption of the transceiver in the transmit mode and thereby to give a warning of an unduly extended transmission, e.g. by faulty equipment.

Claims

1. In a simplex radio transmitting and receiving apparatus comprising a selector switch means, operation of which causes the apparatus to change from a receiving mode into a transmitting mode, transmission blocking means arranged to prevent selection of the transmitting mode if a signal of predetermined strength is being received by the apparatus at the time the selector switch means is operated, and an over-ride circuit whereby operation of the transmission blocking means may be selectively over-ridden to enable the transmitting mode to be selected, the improvement which comprises means within said over-ride circuit responsive to a control signal generated by said selector switch means to initiate operation of said over-ride circuit, and means within said over-ride circuit responsive to return of said selector switch means to select the receiving mode of the apparatus to terminate operation of said over-ride circuit.

2. Apparatus as claimed in claim 1, wherein said means within said over-ride circuit responsive to the control signal is adapted to respond to repeated operation of said selector switch means within a predetermined time interval.

3. Apparatus as claimed in claim 1, wherein said selector switch means comprises a plurality of selector switches electrically connected in parallel.

4. In a simplex radio transmitting and receiving apparatus, comprising a selector switch, operation of which causes the apparatus to change from a receiving mode into a transmitting mode, transmission blocking means arranged to prevent selection of the transmitting mode if a signal of predetermined strength is being received by the apparatus at the time the selector switch is operated, and an over-ride circuit to cause the operation of the transmission blocking means of preventing transmission mode selection to be selectively over-ridden to enable the transmitting mode to be selected, the improvement which comprises means for generating a control signal, means within said over-ride circuit responsive to said control signal to initiate operation of said over-ride circuit, and means within said over-ride circuit responsive to return of said selector switch to select the receiving mode of the apparatus to terminate operation of said over-ride circuit.

5. Apparatus as claimed in claim 4, wherein the means for generating a control signal comprises an over-ride switch adjacent to said selector switch.

6. Transmission control means for a radio transmitting and receiving apparatus having a transmitter circuit and a receiver circuit, the apparatus comprising:

a transmit press-switch coupled to a transmitter control circuit, operation of the press-switch causing the transmitter control circuit to operate to select operation of the transmitter circuit of the apparatus;

a switching means connected between the transmit press-switch and the transmitter control circuit;

a detector connected to the receiver circuit of said apparatus, the detector being operably connected to said switching means and arranged to detect receipt of a signal by the receiver circuit, whereby when a signal is detected the detector causes the switching means to open the circuit between the press-switch and the transmitter control circuit until said signal is no longer detected; and

an over-ride circuit which comprises control signal detecting means, an over-ride control circuit, and mode-detecting means, the over-ride control circuit being activated by the control signal detecting means upon receipt of a control signal to over-ride operation of the switching means by the detector to close again the circuit between the press-switch and the transmitter control circuit, the mode-detecting means detecting the mode in which the apparatus is operating, and serving to de-activate the over-ride control circuit when a return to the receiving mode is detected.