|INTERMEDIATE-STATION TELEPHONE FOR METALLIC CIRCUITS No. 335.
This instrument is practically similar to No. 325, but constructed for metallic circuits.
The external arrangements are similar to No. 330, with five-magnet Generator No. 478, 1000 ohm bell in shunt on the line, hand micro-telephone No. 530 with cord No. 2061, and a battery box to accommodate two cells No. 586 or 971.
This instrument is constructed for three metallic circuits, and, by the addition of an extension bell No. 426 in shunt on the third line, it will be found very suitable in places where signals have to be given on the two Main lines 1. and 2., and where connection with a third line is also desired. When the switch lever is pointing to the left or to the right a signal from 1. and 2. will ring the bell of the instrument, and a signal from 3. the extension bell; with the switch lever in its vertical position through signals and conversations cannot be overheard. line 3. cannot ordinarily be connected to lines 1. and 2., but by using switch No. 465 line 3. may be brought into connection with lines 1. and 2., and vice versa. The instrument in this latter arrangement must be used on metallic circuits only.
Weight 21.20 lbs.
Price £5 1 0s.
Renumbered later as the AD 250.
Last revised: September 30, 2019