G.P.O. No83 GALVANOMETER IN LEATHER CASE, 1930's

GPO engineers Tangent Galvanometer in leather case Type No 83 maker unknown.

A1527

SILVERTOWN TELEGRAPH WORKS GALVANOMETER, 1930's

Used to detect current in either direction in Telegraph circuits on receiving or sending stations. Also used as test equipment and known as a differential type. Made at the Telegraph Works Silvertown.

A1469

GPO 970 DIFFERENTIAL GALVANOMETER, 1930's

Used to detect current in either direction in telegraph circuits on receiving or sending stations. In Differential mode two coils deflect the needle left or right; if the current through both coils is equal then the needle will remain central.
Also used as a piece of test equipment.

A0239

POST OFFICE GALVANOMETER GPO 41, 1930's

Used for indication of signal direction ( Current ) in telegraphy systems also as a test instrument.

A0241

EDISWAN GALVANOMETER, 1930's

Used to detect current in either direction in telegraphy systems.
Also as test equipment.

A0240

SILVERTOWN GALVANOMETER, 1916

Used as either a piece of test equipment or to send or receive Morse.
The needle could deflect either left or right dependent on the direction of the current,or could measure the strength of the current by the deflection measured in degrees.

A0328