GERMAN TELEPHONE EXCHANGE SIEMENS

Believed to have been made by Siemens in Germany during WW2 but there is no military markings on the unit. Switching is achieved by loose cords and plugs, with flaps on the front to indicate that a phone has been lifted, buttons on the front can select one circuit at a time presumably for the operators headset. Dated 1940

A1446

ADVANCE PRIVATE AUTOMATIC EXCHANGE (SWITCHBOARD) MASTER STATION, 1970's

Transistorised unit with speech amplifier for office communications.
The dial mounted on the front is for internal dialling.

A0047

PO WALL CLOCK, 1970's

Slave units used in Telephone Exchanges and also in Post Offices for many years, these were driven by a master long case clock situated in the Exchange.

See Item A0073

A0351

GPO EXCHANGE OR MASTERCLOCK, 1960's

Pendulum clock used in telephone exchanges, for timing functions.
Item A0357 is the relay unit for this.
Using the Hipp toggle principal which swings the pendulum by pulling it every so often by a magnet powered by electric pulses, supplied only when the momentum of the swing started to die.
This unit uses a modified version of this system.
Matthaeus Hipp in 1838 is reported to have invented the toggle in a dream, at a very early age. He got up and drew it immediately. This is almost certainly fiction.
This item is working in the museum and running six clocks.
See http://www.electric-clocks.nl/clocks/en/page04.htm for the history

• A0357 - EXCHANGE CLOCK CONTROL UNIT
  

A0073

EXCHANGE CLOCK CONTROL UNIT, 1940's

Used to control equipment connected to the exchange master clock
Item A0073.

• A0073 - GPO EXCHANGE OR MASTERCLOCK,
  

A0357

GPO ENGINEERS BUTT No 280, 1960's

Used by engineers in telephone exchanges, and on the road for testing telephone lines.

A0043

PAY PHONE DISK TEST COINS, 1970's

Used for checking operation of telephone coin boxes.
Sizes are early Metric type.

A0060

GPO ENGINEERS CLEANER BLOWER, 1950's

Used by cleaners and engineers to blow the dust from telephone equipment.

A0064

GPO TELEPHONE OPERATORS HEAD SET, 1950's

Headset used by manual switchboard operators.

A0062

GPO CHEST MICROPHONE, 1940's

Transmitter Breast Sound Powered No2-Mk3
Used by Telephone Switchboard Operators.

A0908

25 x 4 UNISELECTOR No 15A, 1950's

Uniselector for use in Private Automatic Exchanges (PAX).
Origin Unknown.

A0562

STROWGER MULTI-SELECTOR (UNIDENTIFIED), 1950's

Multi selector for use in large Private Automatic Exchanges (PAX)

A0564

STROWGER Type 2000 SELECTOR, 1970's

Type 2000 Strowger Selector for automatically connecting up to 100 telephone circuits to one.
The type 2000 Strowger selector is part of a 'Final' type selector, although many types of Selector are used together to establish a final connection, each one having a specific task. The way the call is finally connected is to complicated to explain here. This unit is used in the museum to demonstrate the Strowger principal. Almon Brown Strowger conceived his idea in 1888 and obtained a Patent in 1891. He was an Undertaker whose business was being deprived of customers due to a manual operator lessening in to his calls. She being the wife of a competitor whose husband was stealing his work, Strowger was so upset by this he decided to find a way of eliminating the position of manual switchboard operator.

This item can be demonstrated.

• Watch the multi-selector in operation on E2BN
  

A0559

PO PRE 2000 SELECTOR, 1950's

Exchange Strowger Selector. Used before the new 2000 series, which looks similar.
For automatically connecting up to 100 telephone circuits to one.
If more units are linked together complete telephone numbers can be selected.

The unit is shown on its side, for the correct orientation see Item A0559

• A0741 - 2000 STROWGER FINAL SELECTOR
  

A0951

STROWGER SELECTOR, 1970's

Strowger type multi selector in use up until the late 70's.
Up to 100 telephone lines can be selected with this unit.

The unit is shown on its side, for the correct orientation see Item A0559

A0741

GPO DYNAMOTOR No 50A, 1970's

Dynamotor for generating all the tones necessary in a telephone exchange including the voltage for the ring signal.
also the tones including, Park, Busy and Number unobtainable etc.

This item can be demonstrated.

A0558

SIEMENS EXCHANGE RING GENERATOR, 1950's

Used in small telephone systems for creating enough voltage to drive telephone bells.

A0083

ERICSSON PMX 5 x 40 SWITCHBOARD, 1940's

Made by L.M.Ericsson and imported.
Early style manual Switchboard.

• Watch the Exchange in Operation on E2BN
  

A0059

1 x 3 SMALL DOLLS EYE EXCHANGE (SWITCHBOARD), 1940's

Small manual telephone exchange for one exchange line and three extensions.

A0528

GPO 5 x 20 DOLLS EYE EXCHANGE (SWITCHBOARD), 1950's

Standard GPO design of manual type 'Dolls Eye' Switchboard.

• Watch the Exchange in Operation on E2BN
  

A0058

GPO 2 x 4 DOLLS EYE SWITCHBOARD, 1950's

Manual switchboard used in offices between the Wars and after.
Diagram for this unit is N935. (Called 'N' diagrams by the GPO) Possibly dated May 1959

A0046

RELIANCE PAX, 1940's

Donated by The Forest of Dean Railway Company where it was in use. Restored and repaired and now in fully working order. PAX stands for Private Automatic Exchange. Some parts are dated 1946.

This item can be demonstrated.

A0050

GPO MACADIE KEY SENDER, 1950's

These units were designed to help Telephone Operators with the fatigue caused by continuous dialling.Invented by Donald Macadie. Patent June 14, 1932

A0021

GPO TIMER 70A, 1950's

Timer unit driven by exchange clock and used for timing functions in the exchange.

A0079

GPO TIMER 62A, 1970's

Used for timing functions in exchanges and driven by the exchange clock.

A0080