GPO Pattern No.1 Resistance Bridge

 

GPO pattern Number 1 Resistance Bridge Resistance box 0 to 4400Ω. Resistors are manganin wire wound on ceramic formers. Ebonite front panel, steel ventilated enclosure with brackets for fixing to bench, two brass plugs missing. The right hand knob had been broken in the past and was absent when I received the instrument, the one now fitted came from a WW2 WS18. Working and accurate, UK manufacturer and date unknown, perhaps before 1915.

This is one of many instruments collected by Jack Davidson C Eng FIEE which I have been given by Dr Graham Winbolt