ATM TELEPHONES T.3904

 
Mining Telephone
CERTIFIED SURFACE TYPE MAGNETO TELEPHONE
Mines Department Certificate No. T/Tel/8. Wall Pattern

This Telephone is certified by the Mines Department as being intrinsically safe for surface use only, and is suitable for inter-connection with any approved magneto telephone system, the generator being fitted with a non-inductive shunt and the ringer shunted by an approved condenser.  It is fitted with a hand microtelephone of the B.P.O. standard design, incorporating an approved design of transmitter.

T.3904 Wall Pattern Surface Type
The case of this telephone is designed to hold the two dry cells for speaking purposes, thus making a self-contained unit.

Height 11in; width 11in; depth 6.5in;
Weight 12.5lbs
Price : £6.1.0

Two-cell Battery Box for T.3903 Telephone (T.4651A)
Oak cover polished finish with hook and eye fastener.

Height 4.5in. width 3.75in. depth 2.5in.

Needs two T.2190 Dry Cells for T.3903 Telephone

 

Taken from the A.T.M. Mine Telephones and Signalling Equipment Book - April 1939

 
 
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Last revised: November 05, 2022

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