General Information

Serial #

710

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

CAST ALUMINUM CASE; SYNTHETIC DIALS & CONNECTORS; METAL, GLASS & SYNTHETIC COMPONENT PARTS

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

14.0 cm

Width

13.9 cm

Height

15.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Communications

Category

Radio

Sub-Category

N/A

Manufacturer

AKA

GENERAL RADIO

Country

United States of America

State/Province

Massachusetts

City

Concord

Context

Country

North America

State/Province

Unknown

Period

THIS TYPE OF VOLTMETER USED C.1935-1940

Canada

Unknown

Function

TO MEASURE THE VOLTAGE OF AN UNKNOWN RADIO FREQUENCY SIGNAL BY COMPARING THE DETECTED CURRENT WITH A KNOWN 6D CYCLE POWER SOURCE. THE COMPARED VOLTAGE IS READ FROM THE CALIBRATED VOLTS DIAL.

Technical

EXAMPLE OF AN INSTRUMENT USED IN EARLY RADIO FREQUENCYCURRENT MEASUREMENT. THIS TYPE OF INSTRUMENT WAS NECESSARY BECAUSE TECHNOLOGY HAD NOT PROGRESSED TO THE POINT THAT RF CURRENT COULD BE MEASURED DIRECTLY.

Area Notes

Unknown

Details

Markings

TOP PANEL STAMPED: 'VOLTMETER INDICATOR/ TYPE NO./ 874-V1/ SERIAL NO./ 710/ [GR LOGO]/ GENERAL RADIO CO./ CONCORD [REGISTERED TRADEMARK SYMBOL] MASS., U.S.A.'/ 'CRYSTAL CURRENT', 'CAL/ POWER', 'INPUT', 'SENSITIVITY', & 'CAL VOLTS' CONTROLS LABELLED/ METER FACE BEARS SCALE O-200 & TEXT 'MICROAMPERES/ DIRECT CURRENT/ MARION ELEC. INST. CO. U.S.A.'/ OPERATING INSTRUCTIONS APPEARS IN FULL ON WHITE LAMINATED PANEL MOUNTED ON VOLTMETER BASE

Missing

NONE

Finish

BLACK WRINKLE-FINISH ENAMEL ON LOWER CASING; BLACK SIMULATED LEATHER FINISH ON TOP; BLACK & GREY CONTROL DIALS. INSTRUCTIONS PRINTED ON WHITE LAMINATED CARD MOUNTED ON UNDERSIDE OF VOLTMETER

Decoration

NIL