Operation - Bell System Practices Plant Series Service

SECTION 512-620-100
feet of shielded cable from master 670A transmitter
to auxiliary 671A transmitters.
on speakerphone conference system for connections.
(8) Make connections as shown in appropriate
figures of this section or other sections in
Division 512 for specific telephone set connections.
3.03 The 55-type control unit can be used where
necessary to cut off common ringers or
signals to prevent pickup by speakerphone. This
feature can be provided through break contacts of
Kl relay in control unit. Refer to section in Division
512 for specific telephone set involved.
D-180196 Kit of Parts
3.04 The 667B transmitter, when installed in
certain CALL DIRECTOR telephone sets is
subject to pickup of mechanical spring vibrations
when a held line button is released and the
speakerphone system is on.
transmitted though the control unit and back over
the line. To eliminate this condition the 667B
transmitter should be replaced with one modified
by Western Electric service center, ordered as
follows: "Transmitter, 667B, Modified per D-180196."
3.05 Packed with the modified 667B transmitter
is a piece of split vinyl tubing to be
assembled to the key pivot bar spring of the
telephone set during installation of the transmitter.
Note: CALL DIRECTOR telephone sets may
be ordered with the modification installed by
specifying "Modified per D-180196."
4.

OPERATION

Note: 3-type speakerphone system permits
normal use of the telephone set for originating,
receiving, or transferring calls.
4.01 To originate a call using speakerphone:
(1) Depress transmitter ON button and release.
ON lamp will illuminate indicating speakerphone
is in the talking condition. Listen for dial tone
transmitted through loudspeaker. Telephone set
handset is not lifted (except where handset
covers dial).
(2) Operate dial of telephone set in normal
manner.
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Refer to section
This vibration is
(3) When complete number is dialed, ringing
tones, busy signals, and called party answer
will be heard from the loudspeaker.
(4) When called party answers, transmitter and
loudspeaker are used to carry on a hands-free
conversation. Adjust volume level as desired.
Note: Best operational results are obtained
at the lowest acceptable volume settings.
(5) When originating calls from telephone sets
which require off-hook dialing, the ON button
must be depressed and held upon completion of
dialing until the handset is restored.
4.02 To answer an incoming call using speakerphone:
(1) Telephone set ringer signals an incoming
call.
(2) Depress ON button on transmitter. Ringing
is tripped and system is automaticaly connected
to the line by the control unit.
4.03 To disable transmitter when it is desired
not to transmit conversation in the room to
a distant party:
(1) Depress ON button to full extent of its
travel and hold down during entire time
transmitter is to be disabled.
Note: With transmitter disabled conversation
will not be transmitted to the distant party,
however, distant party can still be heard over
the loudspeaker.
(2) After private conversation is completed and
it is desired to transmit to distant party
again, release ON button. System is now restored
to full hands-free capability.
4.04 To terminate a call on speakerphone: Depress
OFF button on transmitter. ON lamp will
extinguish and control unit will be restored to the
idle condition.
4.05 Transferring from handset to speakerphone
operation:
(1) After dialing or during a conversation depress
and hold ON button of transmitter.