HMV SB200 6-valve bandspread radio, some model tags stamped S200.
This was HMV's first bandspread radio, designed and built for them by Collier and Beale in Wellington.
The model date was either 1940 or (most likely) 1941, confirmation required. Advertising appears to have started mid-1941. Some adverts show a slightly different cabinet and dial layout as per the two below - most likely these are the same electrically though.
Otago Daily Times, 22 May 1941
The Listener 18 July 1941
Valves (6 + magic eye):
Intermediate Frequency: 465kc/s
Frequency Bands: 5
Chassis Notes(most schematics can be clicked to download a full size version)
Service information (HMV_200SB_-_6V_Bandspread_AC_-_1940-41.pdf) here
Service information (HMV_200SB_-_technical_notes.pdf) here
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.