Mounting Cord; Handset; Rotary Dial (Ne-500 Type); Digitone* Dial (Ne-2500 Type) - NORTHERN ELECTRIC NE-500 Identification, Installation, And Maintenance

2.02 The NE-1500 (MD) and NE-1554 (MD)
type telephone sets are identical to the
NE-500 and NE-554 type except they are equipped
with a 10-button NE-25 type DIGITONE dial.
2.03 The NE-2500 and NE-2554 type telephone
sets are similar to the NE-500 and NE-554
except they are equipped with an NE-35 type
DIGITONE dial.
COMPONENTS
2.04 All components (except the line switch
plungers on the desk type telephone sets)
are mounted on the base of the set. The line switch
plungers are part of the housing assembly.
A. Mounting Cord
2.05 NE-500, NE-1500 and NE-2500 desk type
telephone sets are provided with a 5-1 /2
foot mounting cord, which may be replaced with a
9- or 13-foot NE-D type 3-conductor cord, or a
13-foot NE-D type 4-, 6-, 10- or 16-conductor
cord. The mounting cord is connected to the
service leads through the appropriate connecting
block.
B.
Handset
2.06 All sets are shipped with an NE-G3AR
handset. The handset may be replaced with
a handset containing an amplifier, such as the
NE-G6AQ lA for customers with impaired hearing,
or an NE-G7 AQ lA for customers with impaired
speech. An NE-G8AQ1A handset may be used
in
noisy locations.
C. Rotary Dial (NE-500 Type Sets)
2.07 Most NE-500 type telephone sets are
equipped with QDB 1 type dials. The NE-7
(MD) type dial is superseded by the QDB 1 type
dial. The rotary dial is available with or without
the word "OPERATOR" printed on the number
plate and must be specified when ordering.
SECTION 502-5101-201
D. DIGITONE Dial (NE-2500 Type Sets)
2.08 NE-2500 type DIGITONE sets are equipped
with NE-35Q3A 1 12-button dials. The
NE-25 type 10-button dial and NE-35 type
12-button dial are MD and are superseded by the
NE-35Q type dial. The wiring connections for the
NE-35Q type dial differ from the NE-25 type and
NE-35 type dials and circuit modifications must be
performed as detailed in the appropriate section.
The two additional buttons on the NE-35Q type
dial are designated
*
and
t:t.
While operational,
their use is restricted to end-to-end signaling. The
DIGITONE dial is available with or without the
word "OPERATOR" printed on the "O" button,
and must be ordered accordingly.
2.09 The NE-35Q type dial assembly contains a
line-powered oscillator, which generates two
frequencies when a button is depressed. These
frequencies are transmitted to the CO, which must
be equipped with a converter. The converter
accepts the oscillator signals and translates them
into a 2-out-of-5 code for crossbar offices, or dial
pulses for step-by-step offices.
E. Line Switch
2.10 The card-operated line switch uses
bifurcated contact springs to improve
reliability. These are protected by a plastic cover.
The line switch is held in the off-hook position by
a coil spring. The weight of the NE-G 3AR handset
is sufficient to overcome the force of the coil
spring, allowing the card to return the line switch
contacts to the on-hook position.
F.
Ringer
2.11 Most telephone sets are equipped with
NE-C4A ringers. The ringer volume may be
adjusted for four levels using the four
corresponding positions of the volume control,
(Fig. 7 and 8). A fifth position is supplied for
manual ringer cutoff, an installation option.
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