BELLSET No. 7
Wall mounted switch unit for extension plans 5 & 7 on CBS No. 1 systems and fitted close to the main telephone.

For 1 exchange line and 1 extension with intercommunication (only during an exchange line transfer), with or without secrecy.

Wooden construction with ringing generator, four position switch, indicator and magneto bell.

Introduced in 1923.

Diagram - N507.

Bellset includes (1928):-
Refer to table below.

  Mark 234 Mark 235 Mark 236
Diagram - C.B.S. 189 257 500
Bell No 1A, unmounted (with Bell-gongs No. 17) 1 1 1
Condenser, M.C., No. 1 - - 1
Generator No. 4C 1 1 1
Indicator and Key No. 3 1 - -
Indicator and Key No. 5 - 1 -
Indicator and Key No. 9 - - 1

Adjustment of Magneto bells
 




 

Bell set No. 7 interior

 
 
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Last revised: November 09, 2020

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