Toa EXES-6000, Operating And Troubleshooting

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1-3. Handset to Handset Mode
Assume that in Fig. 23, both stations A and B are
in the handset mode and connected.
(1) A 40Hz handset mode signal and voice signal
are transmitted from the both stations to the
DL unit via the LM unit and HW-T.
(2) The 40Hz handset mode signal (A) proceeds
to 40Hz SIGNAL DETECTOR (A) and another
40Hz signal (B) to 40Hz SIGNAL DETECTOR
(B), resulting in a high level output at the both
detectors. Similarly, each of the both voice
signals is transmitted to VOICE SWITCH (A)
and (B), respectively via HPF. The status of
logic elements after this stage are shown in
Fig. 26.
Fig. 26 Status of Logic and Voice Signal Flow
in Handset to Handset Mode
Both VOICE SWITCHES (A) and (B) close, provid-
ing full duplex conversation. In this event, the side
tone circuit is activated, and the both stations (A)
and (B) enable its talker to hear his own voice
from its handset ear speaker.
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