Bell 4A Manual

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BELL SYSTEM PRACTICES
AT&TCo Standard
SECTION 512-700- lOD
Issue 2, September 1974
4A SPEAKERPHONE SYSTEM
1. IDENTIFICA TiON
1.01
The 4A speakerphone system is a hands-free
voice switched system for use as a telephone
adjunct and is a replacement for the 3-type
speakerphone system.
1.02
This section is reissued to add information
on:
• lOSAR loudspeaker set
• 680AR and 680AR14 transmitters
• 82B connecting block
• Station busy lamp circuit
1.03
The 4A speakerphone system consists of a
transmitter, loudspeaker set, power unit,
and either a connecting block or adapter that when
connected to a suitable telephone set, provides:
o Hands-free telephone operation
• On-hook dialing (when dial is not obstructed)
• Automatic switching from speakerphone to
handset operation
•Transmitter muting for private conversation
• Visual indication when system is in use
• Cutoff common ringer or other signaling
devices when desired.
1.04
Components of the 4A speakerphone system
!ire shown in Fig. 2.
1.05
This system may be used with the lA, lAl,
and 1A2 key telephone s '.ems and all PBXs.
1.06
For additional schematic ant! circuit information
refer to SD- and CD-69909-01, respectively.
Ordering Guide
1.07
Components which make up the 4A speakerphone
systems are ordered separately as follows:
•Set, Loudspeaker, 108A-* (includes 7-foot ·
D20N mounting cord)"
••Set, Loudspeaker, 108AR-* (includes 7-foot
D20N mounting cord) for use when radio
frequency interference is a problem•
•Transmitter, 680A-* (includes 7-foot, DSS
mounting cord)
••Transmitter, 680Al4-* (includes 14-foot,
DSS mounting cord)
•Transmitter, 680AR-* (includes 7-foot, D8S
mounting cord) for use when radio frequency
interference is a problem
• Transmitter, 680AR14- * (includes 14-foot DSS
mounting cord) for use when radio frequency
interference is a problem•
• Unit, Power, 85Bl-49
• Only one required-either Block, Connecting,
82B-49 or Adapter, 223A-49 (includes 7-foot,
M16C and 25 foot M2FG cords).
Note: •The 82B (when it becomes available)
may be substituted for the 82A connecting
block.•
•Add color suffix.
1.08
Mounting cords are available only in satin
silver ( - 87). The M2FG cord or the 223A
adapter only comes in 25 foot length.
A 14-foot cord may be ordered for field replacement
for the loudspeaker set or 223A adapter. Example:
Cord, D20N-87, 14 feet
Cord, M16C-87, 14 feet
© American Telephone and Telegraph Company, 1974
Printed in U.S.A. Page l