AUTOMATIC ELECTRIC
Technical Bulletin 701-89T
GENERAL TELEPHONE & ELECTRONICS
Issue 1, September 1959

LOUD-SPEAKING TELEPHONE CONVERSION SET TYPE 88AT (TRANSISTORIZED)
File sent:
AECo Bulletin 701-89T Type 88...
 
1. APPLICATION
This conversion set gives loud-speaking service to a subscriber who has
an Automatic Electric Company Standard Type 80 Telephone, Key Feature
Telephone Type 85A, 85B, or 85C, Key-Telephone System Type 86 — 10A or
10A1, or a Western Electric Company Telephone set of the "400" series or
"500" series used in a Western Electric Company No. 1A or No. 1A1
Key-Telephone System.

2. DESCRIPTION
The conversion set  comprises a loudspeaker, 3-conductor cord,
6-conductor cord, and an adapter-unit (consisting of a turn key,
microphone, flashing indicator lamp, and a volume control.)
The purpose of the flashing lamp is to indicate to the subscriber that
he has seized the line.