Altec lansing 436a compressor amplifier schematic

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MiCiOPHONES-[OUDSFEAKEllsfl

Inc LANSING CURPURATIDN
YELEPHDNES CRestzw 551m BRADSHAW 77635.5

9356 SANTA MONICA BOULEVARD, BEVERLY HILLS, CALIFORNIA
AL-1277-1
TECHNICAL LETTER {fig /

b36A AMPLIFIER

The h36A Amplifier is described in the attached Operating Instructions. It is a
compressor of low cost and good quality. This amplifier is being used in a
number of unusual situations and some of these are outlined.

A local newspaper Want Ad Department receives want ads over the telephone from
varying local and suburban districts, and these are transcribed on a typewriter.
The volume has varied over a range of 20-30 db depending upon the loss of indi-
vidual circuits, and considerable parts of the message must be repeated because
of low intelligibility. When the h36A Compressor Amplifier was inserted in the
circuit, the volume from the distant originating area was raised so that it was
equal with the telephone call from a local area and satisfactory transcriptions
were made without repetition.

A local gas company recently instituted a program for teaching their employees

the proper conduct in discussing troubles with customers. An attempt was made

to tape record the telephone conversations and play them back to the employee,

but the volume varied over wide limits and unsatisfactory reproduction resulted.

The h36fi Compressor Amplifier was inserted between the telephone circuit and the .
tape recorder input and by means of the compressor action, the telephone conver- gfi
sation is of sufficient unifonnity in volume so that a good playback is obtained

for instructional purposes.

Recently one of the airlines in Los Angeles discovered that some of their
passenger agents were accepting gratuities so that a custmner could secure a
reservation on a plane and this had resulted in the plane being overbooked. A
supervisory circuit is being installed, using the h36A Compressor Amplifier, 50
that continuous monitoring of the incoming calls can be accomplished.

These examples indicate that there are many places in telephone company opera

tions with business concerns such as the airlines, Western Union, newspapers,
and department stores where this compressor anmlifier can be utilized to improve
services.

A freight trucking organization utilizes a telephone conference system to delay
discussing their many problems regarding re~routing of trucks and repairs on
equipment and other general business. These leased line facilities extend over
distances as great as 1,500 miles. There are several of their staff in each
city who participate in the discussion and a microphone and loudspeaker are
presently used on a press-to-talk basis. The h36A Compressor Amplifier enables
this conversation to be maintained at a uniform volume regardless of the cable'
losses.

AMPLIFIERS-TRANSFORMERS