BELLSET No. 4

This Bellset was originally called the "Intermediate C.B. Switching Set".  It was a wooden Bellset with a four position switch and indicator, for use on C.B. lines.

Introduced in 1909 this Bellset was used on circuits with one exchange line and one extension giving intercommunication with or without secrecy.  It was associated with the main telephone.

On early models there was an Indicator on/off switch on the side of the cabinet.

Two dry battery cells would have been provided to provide speaking current for internal conversations intermediate and main telephones.

Superseded by Bellset No. 20.

Bellset includes (1928):-
1 x Bell No. 1A unmounted (with Bell-gongs No. 17).
1 x Bell-gong No. 2, Oxidized.
1 x Bell-gong No. 2A, Oxidized.
2 x Washers, Locking, 1-2BA.
1 x Condenser, M.C. No. 14 1uf.
1 x Generator No. 4C.
1 x Indicator and key No.1 (for Mark 234) or No. 4 (for Mark 235).
10 x Plates, Connexion, No. 3.
2 x Plates, Connexion, No. 7.
2 x Bell-gong No. 17.

Circuit diagram - N504.
Circuit diagram - C.B. 607 and 608 - Mark 234.
Circuit diagram - C.B. 877 and 608 - Mark 235.

Mark 235

Mark 234