Wheatstone Bridge Type S Test Set No. 5300

Wheatsone bridge with ability to perform Varley and Murray loop tests. Designed for finding fault locations on telecommunication lines.

Portable device in a wooden case. Device utilizes precision wire wound resistors via rotary switches and a galvanometer. Has own batteries (3 x "D" cells) or can be connected to an external supply.

The device can be configured to be a highly accurate resistance.

Functionality is adaptable via knife swtiches. 

An external galvanomter can also be connected.

Instructions for usage and circuit diagram are glued to the inside of the lid.

This bridge was first manufactured in 1915 and continued for several decades.  Early versions used knife switches for the INT/EXT battery, VR/M, R/MV options, and a leather strap handle.  Later versions used a rotating push button, spring loaded INT/EXT battery switch.  The newest versions also used toggle switches for VR/M and R/VM and a hard plastic handle.

See model 5305 for schematic.

Here you find 15 models, 14 with images and 3 with schematics for wireless sets etc. In French: TSF for Télégraphie sans fil.
All listed radios etc. from Leeds & Northrup; Philadelphia