United States Patent
`
`[19]
`
`[11] Patent Number:
`
`5,008,954
`
`[45] Date of Patent:
`Oppendahl
`Apr. 16, 1991
`
`[54] VOICE-ACTIVATED RADIO TRANSCEIVER
`
`[76]
`
`Inventor:
`
`Carl Oppendahl, 27 w. 44th St., #28,
`New York, NY. 10035-6645
`
`,[21] Appl. No.: 587,602
`
`[22] Filed:
`
`Sep. 24, 1990
`
`Related US. Application Data
`
`[63]
`
`Continuation of Ser. No. 334,190, Apr. 6, 1989.
`
`Int. 0.5 ............................................... H04B 1/44
`[51]
`
`................ 455/79; 455/89
`[52]
`[58] Field of Search ....................... 455/78, 79, 82, 84;
`379/389, 390, 406, 407, 409
`
`[56]
`
`References Cited
`U.S. PATENT DOCUMENTS
`
`4,833,452
`
`5/1989 Currier .................................. 455/79
`
`Primary Examiner—Reinhard J. Eisenzopf
`Assistant Examiner—Edward Urban
`
`ABSTRACT
`[57]
`An improved VOX-activated transceiver has a signal
`
`generator provided in conjunction with the VOX cir-
`cuitry to provide audio tones through the earphone of
`the transceiver, to announce the transition to transmit
`mode, or the transition out of transmit mode, or both.
`By listening for the tones, the user can be continuously
`apprised of the status of the transceiver. An open mike
`condition (continuous transmission due to continuous
`microphone signal in excess of the VOX threshold) is
`noted, for example, because the user whose transceiver
`has the open mike will fail to hear the expected tone at
`the beginning or ending of the user’s spoken words.
`Loss of battery power is likewise noted because the user
`will fail to hear the expected tone at the beginning or
`ending of the user’s spoken words. Finally, in transceiv-
`ers having the feature that the VOX circuit is disabled
`for the duration of receipt of a signal above the squelch
`threshold, any resulting transmit starvation will be im-
`mediately apparent beCause the user will fail to hear the
`expected tone at the beginning or ending of the user’s
`spoken words.
`
`8 Claims, 1 Drawing Sheet
`
`ANTENNA
`
`
`
`Page 1 of 8
`
`GOOGLE EXHIBIT 1005
`
`Page 1 of 8
`
`GOOGLE EXHIBIT 1005
`
`

`

`US. Patent
`
`Apr. 16, 1991
`
`Sheet 1 of 1
`
`5,008,954
`
`ANTENNA
`
`
`
`
`VOX
`
`22
`
`vox SENSITIVITY
`
`‘7
`
`VOLUME
`
`FIG.1 (PRIOR ART)
`
`FIG 2
`
`ANTENNA
`
`22
`
`17
`
`
`
`
`31
`
`30
`
`Page 2 0f 8
`
`
`
`Page 2 of 8
`
`

`

`1
`
`5,008,954
`
`VOICE-ACTIVATED RADIO TRANSCEIVER
`
`This application is a continuation of application Ser.
`No. 334,190, filed on Apr. 6, I989.
`The present invention relates to an improved radio
`transceiver, and particularly to an improved voice-
`activated radio transceiver.
`
`5
`
`BACKGROUND OF THE INVENTION ,
`
`10
`
`An essential part of any radio transceiver is the ar-
`rangement for switching between transmit and receive
`modes. With many transceivers, including most ama-
`teur and citizens’ band radios, the switching into trans-
`mit mode is accomplished by the user pressing a “trans-
`mit” button. Such an arrangement, called “push-to-
`talk", gives the user an unequivocal
`indication of
`whether the transceiver is in transmit mode or receive
`
`mode If the button is pressed, the transceiver is in trans-
`mit mode, and upon the release of the button, the trans-
`ceiver goes into receive mode.
`Another technique for controlling the switching of a
`transceiver between receive and transmit modes,
`in-
`stead of using a push-to-talk button, is the use of voice
`actuation. This technique, called “VOX”, used circuitry
`to monitor the signal level from the microphone. When
`the signal level exceeds a predetermined threshold, the
`transceiver switches to transmit mode. Later, the signal
`level will be found to have dropped below a threshold
`(which may or may not be the same as the previously
`mentioned threshold), and when the below-threshold
`condition persists for longer than a predetermined inter-
`val, the transceiver switches back to receive mode. The
`usual (or at least the desired) result when VOX is em-
`ployed is that the transceiver switches to transmit mode
`when the user speaks, and returns to receive mode after
`the user has finished speaking.
`While VOX operation has the advantage that the use,
`can be handsfree, that is, that one need not have one’s
`hands free for pressing the PTT button, it can also have
`disadvantages.
`One disadvantage relates to the user’s potential inabil-
`ity to recognize an “open mike’ condition. For exam-
`ple, the transmit threshold appropriate for one situation,
`such as a quiet room, may be inappropriate for another,
`_ such as a noisy room. Where the ambient noise level1s
`high, the ambient noise by itself, reaching the micro-
`phone, may reach the transmit threshold and cause the
`transceiver to enter transmit mode. This will result in
`unwanted transmission of the modulated carrier, which
`at the very least has the drawback of needlessly con-
`suming power from the power supply, typically a bat-
`tery.’The unwanted transmission has the further draw-
`back of filling the channel and thus interfering with
`other transceivers that would transmit on the channel.
`Finally, there is the'problem that information not in-
`tended for transmission may be transmitted anyway.
`Where the communications channel
`is full duplex
`(e.g. one channel is used for transmit and another for
`receive) the abovementioned problems of unnecessary
`poWer consumption, domination of the transmission
`channel, and unwanted transmission of information may
`arise. With many transceivers, however, the communi-
`cations channel is not full duplex, that is, a single chan-
`nel is used both for transmission and reception. With
`such transceivers, each of the transceivers transmits on
`that channel and each of the transceivers (when not in
`transmit mode) monitors that channel for receiving
`
`15
`
`20
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`25
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`35
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`45
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`50
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`55
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`Page 3 0f 8
`
`2
`information. If and when a particular VOX-type trans-
`ceiver of this type gets “stuck” in transmit mode due to
`a continuing signal in excess of the transmit threshold,
`there is the further problem that for the duration of the
`“stuck” transmit interval, the user of that transceiver
`will be unable to hear anything from other transceivers
`because the transceiver hearing signals from other
`transceivers requires that the transceiver not be in trans-
`mit mode.
`Another drawback of VOX operation is that the user
`may not be aware of the battery having run down, other
`than by noting the‘prolonged absence of an audible
`signal in the earphone.
`Yet another drawback of VOX transmission switch-
`ing is evident, as discussed below, in the case of certain
`transceivers having a combined microphone and ear-
`phone. Such a transceiver picks up the user’s speech by
`conduction through the earphone, and offers the feature
`that thereIS no requirement of a microphone positioned
`at or near the mouth. Another feature of such a micro-
`phone arrangement is that it may be less susceptible to
`ambient noise than a microphone of the type that re-
`ceives air-transmitted sound energy from a position
`near the mouth. A VOX-equipped transceiver with
`combined microphone and earphone offers a hands-
`free, unobtrusive communications capability.
`But in a transceiver having combined microphone
`and earphone, design consideration must be given to the
`problems that might arise due to close proximity of the
`microphone and earphone. It would be undesirable, for
`example,
`if received signals provided to the user
`through the earphone were picked up by the micro-
`phone, thus'triggering a change to transmit mode. One
`way to avoid that difficulty is to provide a “squelch”
`circuit on the receiver, so that only received signals
`exceeding a set threshold are passed to the earphone.
`Signals
`that
`are
`fainter
`than the threshold are
`“squelched”, i.e. are not provided to the audio amplifier
`that drives the earphone. The transceiver thus has two
`modes, often termed “quiet mode” (during which the
`receiver is active but is not providing a signal to the
`earphone) and “receive mode” (during which the
`squelch threshold has been exceeded and a signal
`is
`being provided to the earphone). The transceiver is
`configured so that the VOX circuit (which monitors the
`signal level at the microphone) is only enabled in quiet
`mode. Stated in the converse, the VOX circuit is dis-
`abled whenever the received signal exceeds the squelch
`threshold.
`
`In a transceiver of the type just described, the reli-
`ance on VOX actuation thus has the severe drawback
`
`that there can be “transmit starvation”. During the
`entire time that a strong signal (in excess of the squelch
`threshold) is being received, the user will not be able to
`cause the transceiver to switch to transmit mode by
`talking. This occurs because the VOX circuit is disabled
`when a received signal exceeds the squelch threshold.
`The drawback of “transmit starvation” is exacerbated
`by the problem that the user may not be aware that
`talking is not accomplishing the switch to transmit
`mode. As mentioned above, when a PTT button is
`pushed,
`there is an unambiguous indication that the
`transceiver is in transmit mode. But in VOX mode,
`there will generally be no indication of a successful
`voice-activated switch to transmit mode, and thus no
`clue that an attempt to switch to transmit mode was
`unsuccessful.
`
`Page 3 of 8
`
`

`

`3
`The combined result of the abovedescribed draw-
`backs is that communication between two users can be
`frustrating if both are using VOX transceivers with
`combined microphone and earphone. One user may
`happen to cause an open mike condition, due to (say)
`allowing headgear to rub against the microphone/ear-
`phone and continuously exceeding the VOX threshold.
`The other user will be unable to transmit because the
`received signal, continuously exceeding the squelch
`threshold, will disable the VOX circuit for that user. In
`typical hands-free’applications, such as skiing, bicy-
`cling, and the like, the transceiver is in a pocket or pack,
`so that even if there are indicator lights showing the
`modes (receive, quiet, and transmit) the users will not be
`' able to see them. Thus the first user will be unaware that
`she is causing the open mike condition, and the second
`user will be unaware that her spoken words are not
`being received by the first user.
`It15 an object of the present invention to provide an
`improved transceiver in which users are unlikely to
`unknowingly cause “open mike” conditions. It is a fur-
`ther object of the invention to provide an irnproved
`transceiver in which a user will become immediately
`aware of the condition if unable to transmit. Itis yet
`another object of the1nvention to provide an improved
`transceiver in which the user will more promptly learn
`of loss of battery power.
`
`SUMMARY OF THE INVENTION
`
`In the improved transceiver of the invention, signal
`means are provided in conjunction with VOX circuitry
`to provide audio signals, typically tones, through the
`earphone of the transceiver to announce the transition
`to transmit mode, or the transition out of transmit mode,
`or both. By listening for the tones, the user can be con-
`tinuously apprised of the status of the transceiver. An
`open mike condition (continuous transmission due to
`continuous microphone signal in excess of the VOX
`threshold) is noted, for example, because the user whose
`transceiver has the open mike will fail to hear the ex~
`pected tone at the beginning or ending of the user’s
`spoken words. Loss of battery power is likewise noted
`because the user will fail to hear the expected tone at the
`beginning or ending of the user’s spoken words. Finally,
`in transceivers having the feature that the VOX circuit
`is disabled for the duration of receipt of a signal abOVe
`the squelch threshold, any resulting transmit starvation
`will be immediately apparent because the user will fail
`to hear the expected tone at the beginning or ending of
`the user’s spoken words.
`
`DESCRIPTION OF THE DRAWINGS
`
`The invention will be disclosed with reference to a
`drawing, in which
`FIG. 1 shows a functional block diagram of a VOX-
`operated transceiver according to the prior art;
`FIG. 2 shows a perspective external view of a typical
`VOX-operated transceiver with combined microphone
`and earphone;
`FIG. 3 shows a functional block diagram of an im-
`proved VOX-operated transceiver according to the
`invention, including a rising/falling edge detect circuit;
`and
`
`FIG. 4 shows the inputs and outputs of the rising/fall-
`ing edge detect circuit.
`
`Page 4 0f 8
`
`5,008,954
`
`4
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`
`5
`
`10-
`
`15
`
`20
`
`25
`
`30
`
`35
`
`45
`
`50
`
`55
`
`65
`
`'
`
`FIG. 1 shows a functional block diagram of a VOX-
`operated transceiver, of which a typical example is the
`Radio Shack cat. no. 21-404 transceiver. In such a trans-
`ceiver, received signals from the antenna go to the re-
`ceiver 12, and the signal level received at the receiver is
`provided to a squelch circuit 13. At such time as the
`signal level exceeds the squelch threshold, the squelch
`circuit 13 provides a gating signal to switch 14 and to
`VOX circuitry as discussed below. Presence of the
`gating signal turns on switch 14, providing the received
`audio signal to amplifier 15 and thus to the speaker 16.
`The volume level provided at the speaker 16 is adjust-
`able by the user through volume control 17.
`Speech or Other audio present at the microphone 18 is
`amplified by amplifier 19. The VOX circuit 20 monitors
`the output of amplifier 19 and (if not disabled by the
`squelch gating signal) will generate a transmit control
`signal at line 21 when the output of amplifier 19 exceeds
`the VOX threshold. The VOX threshold may be ad-
`justed by the user by VOX sensitivity control 22.
`The transmit control signal, when asserted, disables
`receiver 12 and enables transmitter 23. Though not
`shown explicitly in the figure, some circuitry, such as
`the RF oscillator, may be shared between the transmit-
`ter and receiver. The transmitter and receiver typically
`operate at 49 Mhz on one of the channels authorized by
`the Federal Communications Commission for unli-
`censed, low-power communications. The power supply
`and on/off switch are not shown, nor are optional push-
`to-talk arrangements. The circuit designs and physical
`layout of components required for such transmitters and
`receivers are well known. The amplifiers 19 and 15 are
`old, as are the VOX 20 and squelch 13 circuits.
`is
`A typical commercially available transceiver
`shown in an external view in FIG. 2. Microphone 18
`and speaker 16 are both contained within earpiece 24;
`the microphone 18 is preferably of the electret—con-
`denser type due to its small size and weight. A flexible
`cord 25 carries shielded signals to the microphone and
`speaker of earpiece 24. The shield of cord 25 acts as an
`antenna as well. Case 26 contains the balance of the
`transceiver, and permits user access to VOX sensitivity
`control 22 and volume control 17, as well as to on/off
`switch 27.
`
`In the improved transceiver of the invention, a rising-
`/falling edge detect circuit and audio oscillator are
`provided as shown in FIG. 3, providing the beneficial
`features of the invention.
`The function of the transceiver in receive mode is as
`described above in connection with the prior art trans-
`ceiver, with received signals from antenna 11 detected
`and amplified by receiver 12 and supplied to squelch
`circuit 13 and to switch 14, and thence to amplifier 15
`and speaker 16.
`to
`The function of the transceiver with respect
`speech or other audio inputs to microphone 18 is largely
`as described aboVe, insofar as the inputs are amplified
`by amplifier 19 and provided to transmitter 23 and an-
`tenna 11. However, the transmit control signal 21 is
`provided not only to transmitter 23 and receiver 12 but
`also to rising/falling edge detector 28. Upon detection
`of a rising or falling edge, the detector 28 sends an
`enabling pulse to audio oscillator 29. The output of
`audio oscillator 29 goes to amplifier 15 and thence to the
`
`Page 4 of 8
`
`

`

`5,008,954
`
`5
`speaker 16, thus alerting the user of a transition to trans-
`mit mode or out of transmit mode.
`FIG. 4 shows in greater detail the input and output
`signals of detector 28. Its input shown by line 30 is the
`transmit control signal 21. Its output shown by llne 31 5
`is the enabling signal to audio oscillator 29. Each transi-
`tion of line 30 gives rise within the detector 28 to a pulse
`of predetermined width as shown by line 31.
`The output of audio oscillator 29 is shown as con-
`nected directly to the input of amplifier 15, but depend- 10
`ing on the output characteristics of switch 14 and the
`input characteristics of amplifier 15 the connection may
`preferably be capacitively coupled or coupled through
`a switch that is controlled by theenabling output of
`detector 28.
`
`15
`
`6
`sound being less than the triggering time of the
`voice activation means,
`whereby the user is alerted that the transceiver has
`entered transmit mode, and whereby the user will
`be made aware of loss of power or of spurious
`continuous transmission.
`2. The transceiver of claim 1 wherein the transceiver
`
`has a microphone and the microphone is integrally
`mounted with the speaker means.
`3. In a transceiver of the type having a transmit mode,
`a receive mode, and a squelched mode, and wherein the
`transceiver enters receive mode upon receipt of a signal
`having a strength greater than a predetermined squelch
`threshold, and wherein the transceiver enters transmit
`mode by voice activation of a voice activation means
`having a triggering time, and wherein the audio signal
`received by the receiver portion of the transceiver is
`.conveyed to the user by speaker means, the improve-
`ment wherein is provided: sound pulse generation
`means responsive to the voice activation for generating
`a momentary alerting sound audible to the user and
`conveyed to the user by the speaker means, said sound
`pulse generation means generating the momentary
`alerting sound at about the time when the transceiver
`leaves transmit mode, the duration of said momentary
`alerting sound being less than the triggering time of the
`voice activation means,
`whereby the user is alerted that the transceiver has
`left transmit mode, and whereby the user will be
`made aware of loss of power or of spurious contin-
`uous transmission.
`4. The transceiver of claim 3 wherein the transceiver
`has a microphone and the microphone is integrally
`mounted with the speaker means.
`5. In a transceiver of the type having a transmit mode,
`a receive mode, and a squelched mode, and wherein the
`transceiver enters receive mode upon receipt of a signal
`having a strength greater than a predetermined squelch
`threshold, and wherein the transceivers enters transmit
`mode by voice activation of a voice activation means,
`and wherein the audio signal received by the receiver
`portion of the transceiver is conveyed to the user by
`speaker means, the improvement wherein is provided:
`sound pulse generation means responsive to the voice
`activation for generating a momentary alerting
`sound audible to the user and conveyed to the user
`by the speaker means, said sound pulse generation
`means generating the momentary alerting sound at
`about the time when the transceiver enters transmit
`mode, the sound pulse generation means further
`cdmprising means for disabling the voice activation
`means for the duration of said momentary alerting
`sound,
`whereby the user is alerted that the transceiver has
`entered transmit mode, and whereby the user will
`be made aware of loss of power or of spurious
`continuous transmission.
`6. The transceiver of claim 5 wherein the transceiver
`
`has a microphone and the microphone is integrally
`mounted with the speaker means.
`7. In a transceiver of the type having a transmit mode,
`a receive mode, and a squelched mode, and wherein the
`transceiver enters receive mode upon receipt of a signal
`having a strength greater than a predetermined squelch
`threshold, and wherein the transceiver enters transmit
`mode by voice activation of a voice activation means,
`and wherein the audio signal received by the receiver
`
`20
`
`25
`
`The audio tone provided at speaker 16 in response to
`the transition into or out of VOX mode is preferably
`quite brief in duration, on the order of a few milliSec-
`onds. Brevity of the tone minimizes its intrusiveness
`when generated as the user starts talking. Furthermore,
`if the microphone is integrally mounted with the ear-
`phone, care must be taken that the tone annunciating
`the transition out of transmit mode does not itself trig-
`ger the VOX circuit back into transmit mode. The typi-
`cal VOX circuit goes into transmit mode only after the
`abovethreshold input has remained above the thresh-
`old for some time, at least a few tens of milliseconds.
`Keeping the tone quite brief Will thus keep it from trig-
`gering a spurious transition into transmit mode.
`Another way to keep-the e'nd-of-transmit mode tone
`from retriggering the VOX circuit is to put a switch in
`the audio path between amplifier 19 and VOX circuit
`20, with the switch controlled by the output of detector
`28, so that the microphone'1s disabled during the brief 35
`time the tone is present
`Many users of VOX equipment develop the habit of
`prefacing each instance of speech with “ahhh” or some
`other sound to trigger the VOX prior to the time the
`words are actually spoken; this reduces the problem of 40
`the user‘s first syllable being cut off due to less-than
`instant VOX switching. Such users are unlikely to mind
`the start-of—transmission alerting tone. But for those
`who find the start-of-transmission alerting tone distract-
`ing or annoying, it may be preferable to configure de- 45
`tector 28 only to generating its enabling pulse at the end L
`of transmission. For other users, the end—of-transmission
`pulse may be the most distracting, and it may be prefera-
`ble to configure detector 28 only to generating its en-
`abling pulse at the beginning of transmission.
`I claim:
`
`30
`
`50
`'
`
`1. In a transceiver of the type having a transmit mode,
`a receive mode, and a squelched mode, and wherein the
`transceiver enters receive mode upon receipt of a signal
`having a strength greater than a predetermined squelch 55
`threshold, and wherein the transceiver enters transmit
`mode by voice activation of a voice activation means
`having a triggering time, and wherein the audio signal
`received by the receiver portion of the transceiver is
`conveyed to the user by speaker means, the improve— so
`ment wherein is provided:
`sound pulse generation means responsive to the voice
`activation for generating a momentary alerting
`sound audible to the user and conveyed to the user
`by the Speaker means, said sound pulse generation 65
`means generating the momentary alerting sound at
`about the time when the transceiver enters transmit
`mode,
`the duration of said momentary alerting
`
`Page 5 0f 8
`
`Page 5 of 8
`
`

`

`7
`portion of the transceiver is conveyed to the user by
`speaker means, the improvement wherein is provided:
`sound pulse generation means responsive to the voice
`activation for generating a momentary alerting
`sound audible to the user and conveyed to the user
`by the Speaker means, said sound pulse generation
`means generating the momentary alerting sound at
`about the time when the transceiver leaves transmit
`' mode, the sound pulse generation means further
`comprising means for disabling the voice activation 10
`
`5
`
`5,008,954
`
`8
`means for the duration of said momentary alerting
`sound,
`whereby the user is alerted that the transceiver has
`left transmit mode, and whereby the user will be
`made aware of loss of power or of spurious contin-
`uous transmission.
`8. The transceiver of claim 7 wherein the transceiver
`has a microphone and the microphone is integrally
`mounted with the speaker means.
`*
`*
`*
`*
`
`"
`
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`Page 6 of 8
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`

`

`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`CERTIFICATE OF CORRECTION
`
`PATENT ND.
`
`;
`
`5,008,954
`
`DATED
`
`; April 16, 1991
`
`lNVENTURfi): Oppedahl
`
`Page 1 0f 2
`
`It is certified that emit appears in the above-identified patent and that said Letters Patent is hereby
`corrected as shown below:
`
`Title page should be deleted to appear as per attached Title page.
`
`Signed and Sealed this
`
`Sixteenth Day of March, 1993
`
`Arrest:
`
`STEPHEN G. KUNIN
`
`Arresting Ofiicer
`
`
`Acting Commissioner (If Patents and Trademarks
`
`Page 7 0f 8
`
`Page 7 of 8
`
`

`

`United States Patent [19]
`Oppedahl
`
`Patent Number:
`[11]
`[45] Date of Patent:
`
`5,008,954
`Apr. 16, 1991
`
`Page 2 of 2
`
`\ [
`
`54] VOICE-ACTIVATED RADIO TRANSCEIVER
`[76]
`Inventor:
`
`Carl Oppedahl, 27 W. 44th St., #28,
`New York, N.Y. 10035-6645
`
`[21] App]. No.: 587,602
`
`[22] Filed:
`
`Sep. 24, 1990
`
`Related US. Application Data
`
`[63]
`
`Continuation of Ser, No, 334.190. Apr. 6. I989.
`
`Int. Cl.5 .............................................. H04B 1/44
`[51]
`
`[52] US. Cl.
`......... 455/79; 455/89
`Field of Search ...................... 455/78, 79, 82, 84;
`[58]
`379/389, 390, 406. 407, 409
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4.833.452
`
`5/l989 Currier
`
`................................. 455/79
`
`Primary Examiner—Reinhard J. Eisenzopf
`Assistant Examiner—Edward Urban
`
`[57]
`
`ABSTRACT
`
`generator provided in conjunction with the VOX circuit-
`ry to provide audio tones through the earphone of the
`transceiver to announce the transition to transmit mode,
`or the transition out of transmit mode, or both. By
`listening for the tones,
`theruser can be continuously
`apprised of the status of the transceiver. An open mike
`condition (continuous transmission due to continuous
`microphone signal in excess of the VOX threshold) is
`noted, for example, because the user whose transceiver
`has the open mike will fail to hear the expected tone at the
`beginning or ending of the user's spoken words. Loss of
`battery power is likewise noted because the user will fail
`to hear the expected tone at the beginning or ending of
`the user’s spoken words. Finally, in transceivers having
`the feature that the VOX circuit is disabled for the
`duration of receipt of a signal above the squelch thresh-
`old, any resulting transmit starvation will be immediately
`apparent because the user will fail or hear the expected
`tone at the beginning or ending of the user‘s spoken
`words,
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`An improved VOX-activated transceiver has a signal
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`8 Claims. 1 Drawing Sheet
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`Page 8 0f 8
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`Page 8 of 8
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