ROBERTSON MODEL 39BC (CIRCA 1939)

The Robertson model 39BC was manufactured for The Robertson Reversible Sewing Machine Co. Ltd by Collier & Beale Ltd in about 1939.

Unknown Roberston model, sold by Robertson Sewing Machines Ltd in Auckland

Seen in Golden Age of Radio, p.37

Technical Information

Valves (5):

Frequency Bands: 1

General Construction Notes for Collier & Beale Ltd:

Model numbering followed no real sensible scheme until around 1940 - and prior to 1934 apparently no model numbers were assigned at all.

From 1940 a 3- or 4-digit system was employed where the first digit indicates the number of valves, the second digit is the number of bands and the third is the year of manufacture.  From 1950 the last digit became two digits, eg: 5151 is a 5-valve broadcast-band only from 1951.

From 1957 model numbers were replaced with model names, ie the Pacemaker Buffalo - which makes the year of manufacture hard to determine unless service info is consulted (although C&B often released service info after the radio, and the date on the service info was for its release, not that of the model.