Coils Induction No.
1 Two windings of 1 Ohm (silk covered copper wire of 25 mils) and
25 Ohms (11 mils). The cores are a 9/32 inch bundle, No. 24 S.W.G.
well annealed, charcoal iron, left black from the annealing process to
prevent eddy currents.
Used on local battery circuits.
The National Telephone Company also produced a similar Induction Coil
with the 1 ohm winding of 20.5 mils and the 25 ohm winding of 10.75
mils. The core was a bundle of 22 mil wire of 5/16" diameter each.
Superseded by Coil, Induction No. 12.
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Coils Induction No.
2 Two windings of 1 Ohm (silk covered copper wire of 25 mils) and
150 Ohms (7 mils). The cores are a 9/32 inch bundle, No. 24 S.W.G.
well annealed, charcoal iron, left black from the annealing process to
prevent eddy currents.
Used on switchboards on local battery circuits.
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Coils Induction No. 3 Two winding
coil with soldered tags.
Inner winding 26 Ohms (tags 3 and 4) and outer winding 17 Ohms (tags
1 and 2).
Superseded by Coil, Induction No. 14.
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Coils Induction No.
4 Two winding coil - self connecting type.
Inner winding 26 Ohms (tags 3 & 4) and outer winding 17 Ohms (tags 1
& 2).
Superseded by Coil, Induction No. 14.
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Coils Induction No.
5 Induction Coil used for vacuum protector testing.
Primary - 0.15 Ohms.
Secondary - 350 Ohms.
With trembler break and 0.02uf condenser.
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Coils Induction No. 6 Rectangular in construction and
consisting of two windings, this Induction Coil was used on Operators C.B. systems.
Coil
Primary - 11 ohms (tags 5 & 6).
1st Secondary - 58 ohms (tags 3 & 4).
2nd Secondary - 240 ohms (tags 5 & 6).
Dimensions of base are 7.1 in x 2 in.
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Coils Induction No.
7 Two windings of 17 Ohms and 26 Ohms.
Used on Supervisors Circuits.
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Coils Induction No.
8 Two windings on a brass frame with black rectangular metal cover.
8 tags.
1st coil - Primary 18 Ohms and secondary 130 Ohms.
2nd coil - Primary 18 Ohms and secondary 130 Ohms with a
non-induction in series of 360 ohms.
Operators circuit on CB No. 1 exchanges.
Supersedes Coil, Induction No.11.
Ericsson Part No. N3506.
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Coils Induction No.
9 Two winding coil with black cover.
Primary 17 Ohms (tags 1 & 2) and secondary 26 Ohms (tags 3 & 4).
Used on Supervisors Circuits on CB No. 1 exchanges.
Mounts on Drilling No. 92.
Ericsson Part No. N3505.
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Coils Induction No.
10 Two winding Induction Coil used on Telephone No. 44.
Primary 1.7 Ohms and secondary 75 Ohms.
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Coils Induction No.
11 Two windings on a brass frame with metal cover. 5
tags.
1st coil - Primary 18 Ohms and secondary 130 Ohms.
2nd coil - Primary 18 Ohms and secondary 130 Ohms with a
non-induction in series of 360 ohms.
Operators circuit on CB No. 1 exchanges.
Superseded by Coil, Induction No. 8.
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Coils Induction No. 12 Two windings
Induction Coil with soldered tags.
Primary 1 Ohm (tags 1 & 2) and secondary 25 Ohms (tags 3 & 4).
Standard for L.B. system telephone and switchboards.
Superseded Coils Induction No. 1 or NT No. 12.
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Coils Induction No. 13 |
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Coils Induction No. 14
Induction Coil with two windings of 26 Ohms (1400 turns) (tags 3 & 4) and 17 Ohms (1700
turns) (tags 1 & 2).
Superseded Coils Induction No's 3 and 4.
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Coils Induction No. 15
Induction Coil with three windings and six connection tags.
Primary 1 Ohm (tags 1 & 2), 1st secondary 19 Ohms (tags 3 & 4) and
second secondary of 38 Ohms (tags 5 & 6).
Used in the Bellset No. 21
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Coils Induction No. 16 Three winding
Induction Coil with 6 connector tags.
Primary 4 Ohm, 1st secondary 20 Ohms and second secondary of 440 Ohms.
Used on operators telephone circuits on C.B. switchboards.
Ericsson Part No. N3532.
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Coils Induction No. 18
Induction Coil with two windings of 17 Ohms (1700 turns) (tags 1 & 2) and 33 Ohms (1400
turns) (tags 3 & 4).
Used with Anti-sidetone Transformer No. 35A.
N.T. No. 4.
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Coils Induction No. 20
Three windings of 30 Ohms (1600 turns) (tags 4 & 5), 200 Ohms (1580 turns)
(tags 3 & 5) and 44 Ohms (2400 turns) (tags 1 & 2).
Also two non inductive resistances of 30 Ohms (tags 3 & 6) and 85
Ohms (tags 2 & 5). Siemens Brothers Induction Coil No. 21.
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Coils Induction No. 21
Used in Local Battery situations.
Three windings of 1 Ohm (400 turns) (tags 1 & 2), 17 Ohms (1000
turns) (tags 3 & 4) and 33 Ohms (1500 turns) (tags 5 & 6).
Used on Telephone No's 250 & 251 and Bellset No's 21, 31 and 37.
No. 21A was a No. 21 complete with two mounting brackets.
In Australia some 300 series magneto phones used the No. 21A as
follows (no winding details):-
1 Ohm between tags 1 & 2 .
17 Ohms between tags 3 & 4.
33 Ohms + 900 Ohms NI between tags 5 & 6
tags 3 & 5 linked.
Specification - D980
Drawing - 9875
Ericsson Part No. N3529 & N3529A.
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Coils Induction No. 22
Mark 1 Three windings of 50 Ohms (tags 3 & 4), 215 Ohms
(tags 3 & 6) and 17 Ohms
(tags 1 & 2).
Also has two non-inductive resistances of 150 Ohms (tags 3 & 7) and
400 Ohms (tags 3 & 5). Click here for more information
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Coils Induction No. 22
Mark 2 Three windings of 54 Ohms (1600 turns) (tags 3 & 4), 415 Ohms (2000 turns)
with 150 Ohm NI resistance in series (tags 3 & 5) and 17 Ohms (2000 turns)
(tags 1 & 2).
Also has three non-inductive resistances of 150 Ohms (tags 3 & 5 with
415 Ohm winding in series), 50 Ohms (tags 5 & 6) and 150 Ohms (tags 3 & 7).
Click here for more information
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Coils Induction No. 23
Three windings of 44 Ohms (tags 1 & 2), 30 Ohms (tags 4 & 5) and
200 Ohms (tags 3 & 5). A NI resistor of 85 Ohms is between tags 2
and 5.
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Coils Induction No. 24
Three windings of 83 Ohms (1600 turns) (tags 3 & 4), 550 Ohms
(2000 turns) (tags 3 & 5) and 21 Ohms (2000 turns) (tags 1
& 2).
Also has two non inductive resistances of 50 Ohms (tags 5 & 6)
and 150 Ohms (tags 3 and 7).
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Coils Induction No. 25
Two windings of 25 Ohms (tags 3 & 4) and 1 Ohm (tags 1 & 2).
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Coils Induction No. 27
An Induction Coil used on many GPO telephones.
Click here for further
information
ETL Part N3520.
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Coils Induction No. 29 Two windings of
36 Ohms (600 turns) (tags 2 & 3) and 135 Ohms (2700 turns) (tags 1 & 2).
Used on Telephone No. 280.
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Coils Induction No. 30
Three windings of 15 Ohms (1220 turns), 10.5 Ohms (666 turns) and 7.5
Ohms (420 turns). Used on the Telephone No. 700.
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Coils Induction No. 31
Three windings of 6 Ohms (315 turns) (tags 2 & 3), 8 Ohms (540
turns) (tags 1 & 2) and 22 Ohms (900 turns) (tags 4 & 5). Used
on Telephone No's 706, 710 and 711.
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Coil Induction No. 32
Three windings of 7 Ohms (235 turns) (tags 2 & 3), 11 Ohms (402
turns) (tags 1 & 2) and 23 Ohms (670 turns) (tags 4 & 5). Used
on Telephone No's 722, 740, 741 and 746. Drawing No.
92682.
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