BELL SYSTEM PRACTICES
AT
&
TCo Standard
SECTION 5 12-730-450
Issue 5, September 1979
660A 1, 2660A 1, AND 2660A 1M TELEPHONE SETS
CONNECTIONS
SPEAKERPHONE SYSTEM-4A
1.
GENERAL
1.01
Refer to Section 512-700-100 for detailed
information on components of the 4A
speakerphone system.
1.02
This section is reissued to:
•
Add information to identify registered and
typical grandfathered arrangements
•
Add safety information for the 85B1 power
unit
•
Delete 4A speakerphone and key telephone
system wiring figures for 660A1, 2660A1,
and 2660A1M telephone sets
•
Delete key telephone system modifications
in Tables A through D.
1.03
This section provides information necessary
to
modify and connect the 660A1 (MD),
2660A1 (MD), and 2660A1M telephone set to provide
speakerphone service (Fig. 1 and 2).
1.04
Rotary dial telephone sets equipped with an
8RA dial must be equipped with an 8CA dial
when used with 4A speakerphone. The second set
of off-normal contacts on 8CA dial shall connect to
same set terminals as P3 and P4 leads from
speakerphone.
1.05
The D6AF or D4BT mounting cord furnished
with 660A1 or 2660A1 sets must be replaced
by a D10R mounting cord (ordered separately). In
addition the telephone set must be modified per
Tables A, B, or C.
1.06
The housing on earlier versions of the
2660A1M telephone set must be notched to
accommodate the M16C (MD) or M16H adapter cord.
Refer to Section 503-100-100 for notching information.
In addition the telephone set must be modified per
Table D.
2.
CONNECTIONS
A. 223-Type Adapter
2.01
Cords from the 108-type loudspeaker set,
680-type transmitter, and 85B1 power unit
are installed in proper receptacle of the 223A (MD)
or 223D adapter.
The cover must be fastened
securely to assure proper mating of connectors.
B.
108-Type Loudspeaker Set
2.02
Loudspeaker set and transmitter must be
placed a minimum of one foot apart.
C. 680-Type Transmitter
2.03
Transmitter must be at least two feet from
the transformer or any ac powered device.
D. 85B 1 Power Unit
2.04
Power shall be supplied by connecting power
unit as shown in Fig. 3 through 6.
2.05
Use an ac power outlet (not under control
of a switch) located as close as possible to
the system being installed. A retaining clamp will
be shipped with power unit and should be mounted
to the ac receptacle to hold power unit securely
to prevent accidental loss of power (Fig. 1 and 2).
Caution:
Never attempt to use the
same power supply for the card dialer
and the
4A
speakerphone system.
2.06
The power unit should be located less than
125 feet from 108-type loudspeaker set when
NOTICE
Not for use or disclosure outside the
Bell System except under written agreement
Printed in U.S.A.
BSP S12-730-450-i05_1979-09-0l.jpg Scanned by Frank Harrell, (Cowboy Frank) Castle Rock, Colorado Feb 23,2012 22:21:03
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