JPH04278728A - Official approval of radio receiver and device therefor - Google Patents

Abstract

PURPOSE: To obtain a monitoring means which monitors a plurality of radio receivers equipped with squelch circuits used for important radio communication such as the aeronautical communication. CONSTITUTION: This device for testing radio receiver is constituted in such a way that pulse generators (clock-driven pulse generators) 2 and 3 which are controlled by a clock signal generator 1 momentarily inactivate squelch circuits at prescribed time intervals by supplying squelch pulses to the circuits. When the squelch circuits are set to inactivated states, a radio receiver is kept in an activated state and the operator is informed of that whether or not the output sound quantity is appropriate through noise burst. A pilot lamp is connected to this device for visually indicating the operating state of a radio receiver.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is applicable to radio receiver operation certification,
More particularly, a method and apparatus for determining the operability of a wireless handset, including using a wireless receiver activation signal squelch circuit to monitor one or more wireless receivers, and identifying which wireless receiver is being monitored. It is related to.

0002

[Technical background] In recent years, wireless receivers using critical radioactive energy communication links in aircraft, tanks, automobiles, etc. have been using so-called "squelch" technology, which silences the wireless receiver until the signal strength reaches a threshold that activates at full listening power. It uses a known circuit. Receivers with squelch have a knob that allows the operator to adjust the critical silence point or "threshold." In some receivers, the adjustment is preset and a pull knob completely deactivates the squelch circuit so that there is no background noise when the volume is turned up. Without the squelch circuit, there would be a continuous noise in the form of a loud screech or crackle, commonly known as background noise. This noise is distracting and unpleasant. For this purpose, a method using a squelch circuit is adopted.

[0003] For example, everything on an airplane, even a small airplane, is duplicated, and is usually equipped with two handsets, one of which is used for emergencies. Although failure is highly unlikely, the probability of causing a failure in the electronic components constituting each handset is approximately 1/1000. If so, there is nothing to indicate when the squelch silent handset becomes a dead handset. This is particularly important when listening in a variety of situations, such as when an aircraft is broadcasting to a facility in a cloud, or where a supervisor must maintain the safety of the aircraft and its passengers, or perform other extremely difficult radio operations. becomes important.

Some pilots and intercoms know which radios are alive by silencing or counter-deactivating the noise. Others leave the squelch control alone and leave it blindly to fate. In other cases, the radio may become out of step due to carelessness, causing communication failure or confusion.

[0005]An interesting reference regarding the general prior art of this technology is US Pat. A prior art example is disclosed in which a diagnostic signal is introduced into the signal incoming path each time it passes to a wireless receiver. This prior art category is distinct from the invention described herein in that it does not use a separate diagnostic signal and periodic deactivation of a squelch circuit as a method of determining the operational status of a radio. differ.

[0006]

In the following description, sub-threshold or approximating sub-threshold refers to a pulse duration that is long enough to be heard without worrying about intrusion.

The present invention solves the problem of determining the operating state of a squelch silent radio, and further reduces the receiver's overall sensitivity to burst noise to a small value below an approximate threshold when no voice signal is present. This adds selectivity to the effective silence performance of the radio and indicates that the radio is active and the volume is properly adjusted. Additionally, the device indicates which radio is properly active if more than one radio is used.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a means for monitoring radio receivers, particularly of the type used in aircraft communications and the like, which employ squelch circuit silencers.

Another object of the present invention is to provide a means for indicating which radios are active and live, even though the radio receivers are substantially silenced by the squelch circuit. .

Another object of the present invention is to provide a means for the radio operator to assure that the receiver is alive and not faulty, even though the squelch circuit essentially silences the speaker or headphones. It is about providing.

Yet another object of the present invention is to prevent accidental confusion of multiple communication radios or multiple communication devices installed on an aircraft.

Yet another object of the present invention is to provide a means for notifying a new pilot or radio operator to observe whether or not a particular radio will be tuned to live conditions. It is about providing.

The various objects mentioned above are achieved by the present invention, namely, by generating narrow repetitive pulses by a clock-driven pulse generator for each radio receiver to instantaneously disable the noise squelch circuit of each radio at predetermined time intervals. and generating an indication that the radio receiver is active and waiting for a radio frequency signal.

[0014] Still other objects will be understood from the accompanying drawings, the claims, and the following description.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the accompanying drawings showing examples.

In FIG. 1, a clock signal generator 1 generates a symmetrical rectangular wave with a transition time interval of about 2 seconds. Radio 1 pulse generator 2 is triggered to generate a 10 ms pulse during the high to low transition (FIG. 2(B)). This pulse is sent to the radio 1 squelch circuit to instantaneously deactivate the squelch circuit. The wireless 2-pulse generator 3 is then triggered by a clock pulse that transitions from low to high. This main pulse pair (FIG. 2(D)) is similarly connected to the squelch circuit of radio 2, momentarily deactivating the squelch circuit and allowing the noise burst to pass through. These pulses are grouped into radio 2 for double pulses and radio 1 for single pulses to identify which radio is being certified.

[0017] The above-described device is suitable for performing voice communication verification as claimed in the present invention since the pilot or operator can hear periodic noise bursts from the "de-squelch" pulse. ing. A radio squelch device causes the radio to remain silent when there is no signal.

The device is enhanced by the use of indicator lights as shown in FIG. Blocks 4, 5, 6, and 7 provide a visual indication of which radios are alive. Light emitting diodes (LEDs) are connected to each radio to indicate when a particular radio is turned on and audibly tuned.

Noise burst amplifier 4 listens to any sound on the headphone audio line. This line is squelched to silence with a zero voice signal when voice transmission reception ceases, even if it is not for a pulsed noise burst. Noise burst amplifier 4 amplifies these noise bursts when listened to at headphone level. This pulse, if present, is amplified in a noise amplifier 4, shaped into a waveform, and applied to a NAND gate 5. This gate sends the noise burst pulse to the Wireless 1 LED light pulse expander 6 if it matches the Radio 1 pulse. Similarly, if the headphone noise pulse wirelessly matches the gate pulse, that pulse is sent to the wireless 2-LED optical pulse expander 7.

If radio 1 and 2 pulses are listened to in a headphone manner coincident with their respective gate pulses, then
Both indicator lights come on. Radio 1 and 2 LED pulse stretchers 6 and 7, when triggered from the NAND gate, cause both LEDs to illuminate for up to 4 seconds between similar pulses. This provides a nearly continuous lighting display to indicate which radio is alive. The short period during which the indicator light flashes is a self-certification feature that indicates that the indicator light is dependent on the audio noise pulse and is therefore a valid indicator.

Reference numerals 5, 6, 8 and 9 turn off both indicator lights when a voice call is received. This is Figure 2
As shown in (J) and (K), the speech signal appears at the instant of sampling during noise pulse verification, so there is a risk of confusing this instruction. This circuit eliminates the problem of both lights lighting up randomly by preventing either indicator from lighting up when audio is present.

[0022] Logarithmic response allows for a wide range of sound level variations in the headphone line.

In the embodiment of FIG. 1 of the invention, the clock signal generator 1, the wireless 1 pulse generator 2, the wireless 2 pulse generator 3, the NAND gate 5 and the wireless 1 LED pulse enlarger 6 are standard 8-pin chips classified as "timer". It may be formed from an integrated circuit (IC) chip. Dual or multiple units may be used for compact packaging. Economical type 555 or 556 is used. The noise burst amplifier 4 uses a 741 operational amplifier integrated circuit IC, and the NAND gate uses a 7400 square NAND gate. The sensed audio signal amplification integrator 8 uses an operational amplifier integrated circuit such as type 741, and the monostable flip-flop 9 uses a timer IC (integrated circuit) such as type 555. These components are shown for illustrative purposes only and are not shown in any way in a limiting sense.

The foregoing describes only one embodiment of the present invention. However, it will be apparent to those skilled in the art that various modifications and changes may be made thereto without departing from the scope and spirit of the invention.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of a verification device of the present invention.

[Fig. 2] Each signal (A) generated using the present invention
(K) is a diagram showing the waveform and/or pulse timing of FIG.

[Explanation of symbols]

1 Clock signal generator 2 Wireless 1 pulse generator 3 Wireless 2-pulse generator 4 Noise burst amplifier 5 Nand Gate 6 Wireless 1 LED pulse enlarger 7 Wireless 2 LED pulse enlarger 8 Sensing audio signal amplification integrator 9 Monostable flip-flop

Claims (12)

[Claims] [Claim 1] When no wireless signal is received,
A radio receiver having an active radio noise squelch circuit that removes ambient noise such as ambient reception noise at a predetermined level, and a squelch control connection point to which a voltage of an appropriate magnitude is applied to deactivate the squelch circuit. by applying continuous short pulses to the squelch circuit and the squelch circuit to instantaneously deactivate the squelch circuit at predetermined time intervals, thereby repeatedly generating short noise pulses in the audio output of the radio receiver. 1. A wireless receiver verification device comprising a clock-driven pulse generator that indicates that the wireless receiver is active and waiting for a radio frequency signal. 2. The short noise pulse output of the wireless receiver is visually monitored, and when the short noise pulse output of the wireless receiver matches the short pulse, the circuit is turned on and a clock-driven pulse generator is connected to the wireless receiver. 2. The apparatus of claim 1, further comprising illumination indicating means added to the squelch control connection point of said radio receiver for indicating the operating state of said radio receiver. 3. The apparatus of claim 1, comprising a plurality of radio receivers and a clocked pulse generator for each radio receiver. 4. The apparatus of claim 3, wherein the clocked pulse generator provides predetermined time intervals and waveforms so that the audio outputs of each radio receiver are audibly distinguishable from each other. 5. The short noise pulse output of the wireless receiver is visually monitored, and when the short noise pulse output of the wireless receiver matches the short pulse, the circuit is turned on and the clock-driven pulse generator sends the signal to the wireless receiver. 5. The apparatus of claim 4, further comprising lighting indicating means applied to the squelch control connection point of said radio receiver as an indication of the operating state of said radio receiver. 6. The apparatus of claim 5, further comprising audio signal response means for switching off an illuminated display means on each radio receiver when said radio receiver receives an audio signal. 7. In verifying the operating state of at least one wireless receiver having a squelch circuit, the audio output of the wireless receiver is adjusted by repeatedly applying short pulses to the squelch control connection point of each of the wireless receivers. repeating short pulses at predetermined time intervals to deactivate the squelch circuit to indicate that the wireless receiver is active and waiting for a radio frequency signal; 1. A method for verifying a radio receiver, characterized in that short pulses are repeatedly applied to a point for a sufficiently short period of time to produce a minimal effect on the pilot or radio operator. 8. The method of claim 7, wherein the repeated short pulses are of sufficiently short duration and small amplitude to be sensed by a pilot or radio operator approximately below a threshold. 9. By repeatedly applying short pulses to the lighting instruction means, that is, by repeatedly applying short pulses to the squelch control connection point of the radio receiver, the radio receiver is activated and is waiting for a radio frequency signal. 8. The method according to item 7, wherein the method indicates that the state is such that 10. In verifying the operating state of at least a plurality of wireless receivers each having a squelch circuit, a short pulse is repeatedly applied from an individually coded pulse generator to the squelch control connection point of each of the wireless receivers. Deactivating the squelch circuit by applying repetitive, identifiable short pulses to the audio output of the radio receivers at predetermined time intervals, such that any radio receiver is active and waiting for a radio frequency signal. By repeatedly applying short pulses from each encoded pulse generator to each radio receiver at predetermined time intervals and waveforms, the audio outputs of the radio receivers can be vocally distinguished from each other. , a method for testing a radio receiver by applying repeated short pulses of sufficiently short duration to each squelch control connection point to have minimal effect on the pilot or radio operator when they occur. 11. Indicating that the radio receiver is active and waiting for a radio frequency signal by repeatedly applying short pulses to the lighting instruction means, wherein the lighting instruction means is normally switched off while the above 11. The method of claim 10, wherein the method is turned on in response to repeated short pulses. 12. The method according to claim 11, wherein when each wireless receiver receives the audio wireless signal, the audio signal response means turns off the lighting instruction means for each wireless receiver.