General Information

Serial #

N/A

Part Number

1

Total Parts

1

AKA

N/A

Patents

N/A

General Description

CARDBOARD WITH METAL GROMMETS

Dimensions

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

Length

21.4 cm

Width

7.7 cm

Height

N/A

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Mathematics

Category

Calculating devices

Sub-Category

N/A

Manufacturer

AKA

PERRYGRAF

Country

United States of America

State/Province

California

City

Los Angeles

Context

Country

Canada

State/Province

Ontario

Period

C. 1973 +/ DONOR USED THESE SLIDE RULES BETWEEN 1974 & 1985.

Canada

AMERICAN MADE SLIDE RULES USED BY CANADIAN PROFESSIONAL ENGINEER IN HIS WORK IN RADIO COMMUNICATIONS. MR. ROSPLESCH WAS REGISTEREDPROFESSIONAL ENGINEER IN ONTARIO & ELECTRICAL ENGINEER FOR GOVT OF CANADA IN WINNIPEG & OTTAWA WHERE HE USED THESE SLIDE RULES BETWEEN 1974-1985.

Function

DEVICE USED TO MANUALLY CONVERT VOLTS TO DECIBELS & DETERMINE RELATIONSHIPS BETWEEN DECIBELS, CURRENT & VOLTAGE RATIOS, POWER RATIOS.

Technical

EXAMPLE OF SPECIALIZED SLIDE RULE. DONOR DESCRIBES THESE AS TOOLS OF TRADE FOR ELECTRONICS ENGINEERS DESIGNING RADIO COMMUNICATIONS LINKS IN YEARS BEFORE SOPHISTICATED COMPUTER PROGRAMS BECAME AVAILABLE. THEY COULD EASILY BE TRANSPORTED FOR USE IN FIELD WHEN RADIO COMMUNICATIONS SYSTEMS WERE BEING INSTALLED OR MAINTAINED.

Area Notes

Unknown

Details

Markings

HANDWRITTEN "M. ROSPLESCH" ON FRONT; WHITE & BLACK LETTERING READS "The Ballantine Rule....Volts dB Power Level" & "BALLANTINE LABORATORIES, INC./ FOUR DECADES OF INNOVATION IN ELECTRONIC INSTRUMENTATION"/ BLACK LETTERING ON BACK READS "The Ballantine Rule....dB Ratio Conversion" & "(C) 1973, PERRYGRAF Div., Nashua Corp., L.A., Cal 90064 Pinted in U.S.A." & "P/N 90100301A"/ BLACK LETTERING, NUMBERS & SCALES ON FRONT & SLIDE, WHITE & BLACK LETTERING ON BACK

Missing

COMPLETE

Finish

MEDIUM & LIGHT BLUE EXTERIOR, WITH WHITE PARTS/ WHITE SLIDE WITH BLACK GRIPS

Decoration

B&W ILLUSTRATIONS OF BALLANTINE PRODUCTS ON BOTH SIDES