| 摘要 |
An improved VOX-activated transceiver has a signal generator provided in conjunction with the VOX circuitry 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 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.
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