General Information

Serial #

N/A

Part Number

1

Total Parts

10

AKA

N/A

Patents

N/A

General Description

cardboard folder in which is mounted a synthetic sheet

Dimensions

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

Length

22.2 cm

Width

10.0 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

Granger

Country

United States of America

State/Province

California

City

Palo Alto

Context

Country

Canada

State/Province

Unknown

Period

1964 +

Canada

An American made manual calculating device used by a Canadian electronics engineer in the course of his work. The previous owner of this calculating device was Mr. Bob Bennett, who was born in 1920 in Fort William, Ontario. He attended McGill University, graduating in 1942 with a degree in electrical engineering. During WWII he was in the Signal Corps, stationed in Ottawa from 1942-1946, and was involved in radio design and development. In 1946 Mr. Bennett joined the Canadian Pacific Railway but rejoined the Army in 1947 and remained until 1960 working in radio telecommunication research and development. From 1960 to 1979 Mr. Bennett worked in the Public Service in electronics and telecommunication engineering, largely with D&D.

Function

A manual calculator used to calculate radio transmission angles between stations in order to select the appropriate antenna.

Technical

This selector enables the user to calculate the optimum take-off angles for skywave transmission between two stations and to identify the antenna from Granger Associates which radiates at these angles. This kit includes 9 plastic transparencies which are placed over a skywave transmission chart which was developed by Professor R.A. Helliwell, Radio Science Laboratory, Stanford University. Granger Associates was a manufacturer of HF radio communications and a provider of engineering services. Its products and services included HF antennas, including point to point and broadcast antennas for fixed and transportable applications; transmitter-to-antenna interfaces, including high power baluns and multicouplers; engineering services for analysing antenna requirements, siting antennas and installation; ionosphere sounders for determining optimum working frequencies in real time on operational HF circuits. Granger Associates also operated out of England, from Ruo House, Broom Way, Weybridge, Surry, England.

Area Notes

Unknown

Details

Markings

white lettering on front reads 'HF ANTENNA/ Granger/ Associates [logo]/ SELECTOR'/ blue lettering on back reads 'Granger/ Associates [logo]/ 1601 California Avenue. Palo Alto, California/ Telephone 321-4175/ TWX 415-492-9377/ Granger Associates Ltd., Ruo House, Broom Way, Weybridge, Surry, England'/ blue lettering inside reads 'ANTENNA RADIATION PATTERNS/ (complete technical data available on request)' and 'HOW TO USE THIS SELECTOR', with instructions and diagrams/ blue lettering on chart reads 'SKYWAVE TRANSMISSION CHART*' and '*developed by Prof. R.A. Helliwell, Radio Science Laboratory, Stanford Unbiversity' with scales

Missing

N/A

Finish

white folder with blue sections/ white synthetic chart

Decoration

N/A