An indicator with no suffix is an unmounted indicator. Suffix
letters A to L represent resistance, with letter M indicating that different
types of indicators are mixed on one mounting strip and letters N to Z representing
dimensions of the mounting strip.
National Telephones Company (NT) indicators are at the end of the list.
Indicator No. 1
Two
coil drop with circular shutter. Used for indicating short
circuits on repeaters.
Resistance - 50ohms.
Uses a
Label No. 14, Black.
Variants:-
No. 1A - 25ohms (both
50ohm coils in series). Telegraph use.
No. 1C -50+50ohms.
Armature and shutter locals.
No. 1D - 100ohms. Armature
locals.
No. 1E - 100ohms. Superseded No. 1D.
No. 1G -
500+500ohms. Armature and shutter locals.
No. 1J - 1000ohms.
Armature and shutter locals.
No. 1J 1/1 - An Indicator No. 1J on
a wooden base. Superseded by the Indicator No. 101AP.
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Indicator No. 2A
A
polarised, two coil drop with circular shutter. 1000ohm
resistance. Used on the Permanent Current system.
Includes:-
1 x Label No. 15.
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Indicator No. 4
A
tubular drop, self restoring, that mounts at 1.25" centres.
This indicator consists of two ironclad electromagnets, with the
back coil actuating the indicator and the front coil for restoring
it to normal.
Indicator No. 4D is shown pictured to the
right.
Variants:-
No. 4A - 50+50ohms with three tags + 450ohms.
No.
4B - 50+50ohms with four tags + 50ohms.
No. 4D - 1000+450ohms.
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Indicator No. 5
A
drum-shaped armature with shutter.
Variants:-
No. 5A -
500+500ohms. Unsheathed for line circuits.
No. 5C -
500+500ohms. Iron and copper sheathed, for cord circuits.
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Indicator No. 6A
A
button that protrudes when operated.
Drawing -
63340.
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Indicator No. 22
A
tubular drop, self restoring indicator.
Variants:-
No. 22A
- Coil resistances of 600+45ohms.
No. 22B - Coil resistances of
1000+100ohms.
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Indicator No.
34
An "eyeball" type indicator of 1000ohms coil
resistance.
Used on Trunk circuits on an intermediate office.
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Indicator No. 100A
A tubular drop with two coils of 500ohms each and a shutter.
Used where Magneto ringing is employed. The drop is restored
by hand.
Includes:-
1 x Label No. 59, White.
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Indicator No. 101
Indicator No. 101AP is pictured to the right.
Variants:-
AN - One No. 100A on a Mounting 96/1A.
Superseded by the Indicator No. 2201AN.
AO - One No. 100A on a
Mounting 96/1B.
AP - One No. 100A in a wooden case of dimensions
4.5" x 3" x 2". Drawing -
EX40286.
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Indicator No. 102
Indicator No. 101AN is pictured to the right.
Variants:-
AN - One No. 100A on a Mounting No. 96/2A.
Superseded by Indicator No. 2202AN.
AO - One No. 102AN in a
wooden case of dimensions 4.6" x 4.75" x 2".
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Indicator No. 103
Variants:-
AN - Three No. 100A on a Mounting No. 96/3A.
AO -
Three No. 100A on a Mounting No. 96/3B.
AP - Three No. 100A on a
Mounting No. 96/3C.
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Indicator No. 105
Variants:-
AN - Five No. 100A on a Mounting No. 96/5A.
Superseded by the Indicator No. 2205AN.
AO - Five No. 100A on a
Mounting No. 96/5B.
AQ - Five No. 100A on a Mounting No. 96/5D.
AR - Five No. 100A on a Mounting No. 96/5E.
AS - Five No. 100A on
a Mounting No. 96/5F.
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Indicator No. 110
Variants:-
AN - Ten No. 100A on a Mounting No. 96/10A.
AP -
Ten No. 100A on a Mounting No. 96/10C.
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Indicator No. 200A
A non-polarised drop, with circular shutter. Coil resistances
are 300+300ohms. Mounts at 1" centres.
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Indicator No. 300A
A non-polarised tubular drop. Coil resistances are
500+500ohms.
Superseded by Indicators No. 1800A or 2200A.
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Indicator No. 400A
An "eyeball" type indicator for line signalling.
Includes:-
1 x Label No. 77.
1 x Plate, Indicator, Front No....
Variants:-
No. 400A - Coil of 80ohms and fitted with a Plate,
Indicator, Front No. 2.
No. 400AA - Coil of 500ohms and fitted
with a Plate, Indicator, Front No. 3.
No. 400B - Coil of 500ohms
and fitted with a Plate, Indicator, Front No. 2.
No. 400B4 - Coil
of 500ohms and fitted with a Plate, Indicator, Front No. 4.
No.
400C - Coil of 1000ohms and fitted with a Plate, Indicator, Front
No. 1.
No. 400C5 - Coil of 1000ohms and fitted with a Plate,
Indicator, Front No. 5.
No. 400D - Coil of 8ohms and fitted with
a Plate, Indicator, Front No. 1. Used on FA systems.
No. 400E -
Coil of 500ohms and fitted with a Plate, Indicator, Front No. 1.
No. 400G - Coil of 300ohms and fitted with a Plate, Indicator, Front
No. 2.
No. 400H - Coil of 50ohms and fitted with a Plate,
Indicator, Front No. 2.
No. 400J - Coil of 900ohms and fitted
with a Plate, Indicator, Front No. 2.
No. 400K - Coil of 1000ohms
and fitted with a Plate, Indicator, Front No. 2.
No. 400L - Coil
of 3500ohms and fitted with a Plate, Indicator, Front No. 1.
Drawing - 8087.
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Indicator No. 401
Any "eyeball" indictor.
Indicator No. 401CN is pictured to the right.
Variants:-
CN - One No. 400C in a teak wooden case with dimensions 3"
x 1.8" x 5". Diagram CBS100. Drawing - 1392.
DN - One No. 400D in
a teak wooden case with dimensions 3" x 1,8" x 5". Used on FA
systems.
HN - One No. 400H in
a teak wooden case with dimensions 3" x 1.8" x 5". Drawing -
1392.
LN - One No. 400L in a teak wooden case
with dimensions 3" x 1.8" x 5". Diagram TG538.
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Indicator No. 500
An
"eyeball" type indicator, sheathed, for cord circuits.
Includes:-
1 x Label No. 77.
1 x Plate, Indicator, Front No....
Variants:-
No. 500A - Coils of 100+100ohms and fitted with a
Plate, Indicator, Front No. 1.
No. 500B - Coils of 1000+1000ohms
and fitted with a Plate, Indicator, Front No. 1.
No. 500B3 -
Coils of 1000+1000ohms and fitted with a Plate, Indicator, Front No.
3.
No. 500B5 - Coils of 1000+1000ohms and fitted with a Plate,
Indicator, Front No. 5.
No. 500B6 - Coils of 1000+1000ohms and
fitted with a Plate, Indicator, Front No. 6.
No. 500C - Coil of
50ohms and fitted with a Plate, Indicator, Front No. 1.
No. 500D
- Coils of 200+200ohms and fitted with a Plate, Indicator, Front No.
1.
Drawing - 8087.
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Indicator No. 600
Circular disc indicator, which was horizontally mounted on
C.B. switchboard keyboards. Nicknamed a sixpenny indicator due to
it's designation in the Western Electric Catalogue as the "Signal
6D".
Includes:-
1 x Glass
No. 10 or 21 (Mark 238).
Variants:-
No. 600A - Coil of
50ohms with a 100ohm non-inductive shunt.
No. 600C - Coil of
33ohms, un-shunted.
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Indicator No. 900A
Indicator with a revolving drum ("eyeball" type) armature and a coil resistance of
1000ohms. Used as a signal for transfer or on line circuits.
This indicator is similar to the Indicator No. 400 but is much
smaller in size.
Drawing - 1979.
Specification - D220.
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Indicator No. 1000
Indicator with a revolving drum armature, used on Bellsets.
Variants:-
No. 1000A - Coil resistance of 75ohms. Used on
the Bellset No. 4.
No. 1000B - Coil resistance of 4000ohms.
Used on the Bellset No. 7.
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Indicator No. 1100
A flag type indicator which has an attached slotted shutter.
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Indicator No. 1200A
Indicator with a revolving drum armature and copper sheathed.
Double coil, each with a resistance of 1000ohms.
Superseded
by the No. 1300A.
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Indicator No. 1300A
Indicator with a revolving drum armature and copper sheathed.
Double coil, each with a resistance of 1000ohms.
Supersedes the No. 1200A.
Drawing - 7471.
Specification - D406.
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Indicator No. 1400A
A two coil drop indicator of 100ohm resistance. Requires a Label No.
100.
This indicator is extensively used on Magneto
switchboards. The drop can operate a bell when released but
has to be restored by hand.
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Indicator No. 1500A
An Ericsson, single coil, drop with a circular shutter.
Coil resistance of 100ohms. Used extensively on ring-off and
clearing circuits. Mounts at 1" centres.
This indicator
has an armature that extends to full length of the coil and is
pivoted at the back end. When the coil is energised the
armature releases the drop flap, which has to be restored by hand.
This indicator has a coil that is fixed to one end of a soft
iron case, thus forming an ironclad electromagnet.
Requires a Label No. 102.
Superseded by the No. 2000B.
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Indicator No. 1600A
An Ericsson, single coil, tubular drop with a circular shutter.
Coil resistance of 1000ohms. Used for Ring-off signals.
Requires a Label No. 102.
Supersedes the No. 300A.
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Indicator No. 1800A
An Ericsson, single coil, tubular drop with a circular shutter.
Coil resistance of 1000ohms. Mounts at 1" centres.
Requires a Label No. 59, White.
Superseded by the No. 2000A.
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Indicator No. 1900A
An Ericsson, double coil, double wound, tubular drop with a
circular shutter. Coil resistances of 500+500ohms.
Mounts at 1" centres.
Requires a Label No. 102.
Supersedes the N.T. No. 1002.
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Indicator No. 2000
An Ericsson, double coil, tubular drop with a circular shutter and
local contacts within the shell.
Requires a Label No. 102.
Variants:-
No. 2000A - Coil resistance of 1000ohms.
Supersedes the No. 1600A.
No. 2000B - Coil resistance of 100ohms.
Supersedes the No. 1500A.
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Indicator No. 2100
A rotary disc indicator. Probably produced by British
Ericsson.
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Indicator No. 2200A
A double coil tubular drop with coils of resistance 500+500ohms,
that can be in series or parallel. Used on CBS and Magneto
P.M.B.X. switchboards.
Includes:-
1 x Label No. 59, White.
Supersedes the No. 1800A.
Drawing - 7791 (Mark 2).
Specification - D476.
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| Indicator No. 2201AP A
Mahogany wooden box, for wall fixing, containing an Indicator No.
2200A
Superseded by the No. 2201AQ
Drawing - 62327.
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Indicator No. 2201AQ
Used with locally powered DC bells
Click here for more information
Supersedes the
Indicator No. 101AN.
Drawing - 71022.
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Indicator No. 2300A
A tubular drop indicator of 1000ohms resistance. Used on
Switchboards, magneto, Cordless, 10 Line (Mark 235).
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Indicator No. 2700A
A 33ohm, flush fitting, disc signalling indicator, used on keyboards.
Includes:-
1 x Glass No. 21.
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Indicator No. 2800A
A 1000+1000ohm, non-inductive, disc signalling indicator with local contact.
Used on test panels. Five terminals.
Includes:-
1 x
Glass No. 21.
Drawing - 9609.
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Indicator No. 2900
A disc signalling indicator with local contact, used on
keyboards or jack panels. Four terminal.
Includes:-
1 x Glass No. 21.
Variants:-
No. 2900A - 1000ohms.
No.
2900B - 2500ohms.
Drawing - 9609.
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Indicator No. 3000A
A 1000ohms, disc signalling indicator, with local contact, used
on jack panels. Three terminal.
Includes:-
1 x Glass
No. 21.
Drawing - 9609.
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Indicator No. 3100A
An "eyeball" indicator, with coil resistances of 1000+1000ohms,
for line use.
Includes:-
1 x Label No. 77.
1 x Plate,
Indicator, Front No. 2.
Drawing -
8087.
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Indicator No. 3300
A disc signalling indicator with an insulated local contact.
For keyboards and jack panels. Four terminal.
Includes:-
1 x Glass No. 21.
Variants:-
No. 3000A -
2500ohms.
No. 3000B - 33ohms.
Drawings -
9609 and 91978.
Specification - D2311.
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Indicator No. 3501AN
Used with locally powered DC bells
Click here for more information
Diagram - N1283.
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| Indicator No. 3700A An
indicator with a drum armature and drop shutter for use at AT and CB
P.B.X. switchboards.
Drawing - 9781.
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Indicator No. 3701AN
Used with locally powered DC bells.
Click here for more information
Drawings - 9813 and 9814.
Diagram - N1283.
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| Indicator No. 3800A An
relay type indicator with a flag operated by the armature with a local contact.
Used on the Indicator and Key No. 12 (Bellset No. 20) and Relay and
Key No. 2. Coil resistance is 50ohms and the local contact is
a changeover type.
Requires:-
1 x Glass No. 23.
Drawing - 62830.
Specification - D1261.
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| Indicator No. 3900A This
is a relay with an armature operated flag, used on the Bellset No.
39.
The flag is marked "Engaged".
Drawing - 62875.
Specification - D1328.
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| Indicator No. 4000A An
indicator with a drum armature and drop shutter for use at AT and CB
P.B.X. switchboards. (Does not respond to dialling pulses).
Coil resistances are 500+500ohms.
Includes:-
1 x Label No. 59, White.
1 x Shutter,
Indicator No. 4000.
Drawing - 62324.
Specification - D1399.
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Indicator No. 4001AN
Used with locally powered DC bells
Click here for more information
Supersedes the No. 3701AN.
Drawing - 71023.
Diagram -
N609.
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| Indicator No. 4013A This
is a relay with an armature operated flag, used on the Bellset No.
44.
The flag is marked "Engaged".
Drawing - 62875.
Specification - D1328.
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Indicator No. 6000A
An indicator that displays digits 0-9 and used on London test
desks associated with Subscribers Apparatus and line tester.
Fixing centres 3.25".
Includes:-
10 x Lamps No. 40A.
Drawings - CD1555 (No. 6000A)
and CD2715 (No. 6000B).
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| Indicator No. 6100A A
display with digits 0-9. Fixing centres 4". Used on
provincial test desks associated with Subscriber Apparatus and line
tester.
Includes:-
10 x Lamps No. 40A.
Drawing - CD1556.
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Indicator NT4 A 500+500ohms two coil drop . Fitted
with two Coils, Indicator, N.T. No. 2.
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Indicator NT8 An indicator.
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Indicator NT10 A tubular drop of 1000ohms coil
resistance. Fitted with a Coils, Indicator, N.T. No. 4.
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Indicator NT11 A 1000ohm tubular drop with three tags.
Fitted with one Coil, Indicator, N.T. No. 5 of 500+500ohms
resistance.
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Indicator NT12 A 100ohm tubular indicator with three
tags.
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Indicator NT1001 A 1000ohm tubular drop with side local
contact spring.
Used on switchboards W.P. D.C. N.T. No's 13-15. and F.P. D.C.
N.T. No's 10,11,20,21 and 22 of WE make.
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Indicator NT1002 A 500+500ohm tubular drop made by
Ericsson. Double wound with a circular shutter.
Requires a Label No. 102.
Superseded by the Indicator No. 1900A.
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