TELEPHONE No. 7

A wooden, wall mounted, C.B. telephone, with a press button switch which was used as an extension telephone in conjunction with a Telephone No. 5, giving intercommunication.

Previously known as the "Telephone, Wall, C.B. with rotary key" it was later renamed as the Telephone No. 7 circa 1911.

For "Secrecy" the links in the telephone should be connected between 1 and 2 and for "Non-Secrecy" between 1 and 3.

This telephone calls the Main Set by intermittently earthing the B line by means of the Rotary Key. This operates the Biased Bell at the main telephone without indicating a signal at the Exchange.

This was the wall equivalent of the table model, the Telephone No. 10.

Found in the 1906, 1909, 1910, 1911 and 1912 Rate Books.

The 1915 rate Book shows the telephone made obscelescent.

Telephone includes (1906, 1909 and 1910)
1 x Cord No. 222.
1 x Induction Coil.
1 x Condenser 4uf.
1 x Magneto Bell.
1 x Siemens Brothers Transmitter C.B.
1 x Bell, Receiver A (1906) or Bell, Receiver B, C or D (1909 and 1910).

Telephone includes (1911 and 1912):-
1 x Hook, Receiver F.
1 x Switch, Receiver No. 2.
1 x Coil, Induction.
1 x Bell No. 1A, Unmounted.
1 x Condenser, M.C., No. 18 or Condenser M.C. 4uf (1911 onwards).
1 x Transmitter No. 1.
2 x Cord, Flexible No. 116.
1 x Cord, Flexible No. 222.
1 x Receiver, Bell No. 1.

Circuit diagram - N107 (dated 1917).

Circuit Diagram - CB140A.

 
 
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Last revised: November 03, 2025

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