The State RBK was manufactured for Wright, Stevenson & Co. Ltd by Collier & Beale Ltd in 1956.

Other radios based on the same chassis:

5-valve broadcast band tablegram.  Late model RBK from Radio Ltd

Technical Information

Valves (5):
Early: 6BE6, 6AR7, 6AV6, 6AQ5, 6X4
Late: 6BE6, EF41, 6AV6, EL41, 6X4

Intermediate Frequency: 460kc/s

Frequency Bands: 1

Chassis Notes(most schematics can be clicked to download a full size version)

Early Model Schematic1951 Ultimate RBK

1951 Ultimate RBK

1951 Ultimate RBK


Late Model Schematic:

1951 Ultimate RBK


Late model chassis - including gram switch and input1956 Ultimate RBK Late Model Chassis inc gram input

1956 Ultimate RBK Late Model Chassis inc gram input

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.

Other documented models using this chassis (5 in total)

1951 Ultimate model RBK 'Tawa'
1951 Ultimate model RBK 'Musgrave'
1951 Ultimate model RBK 'Miro'
1956 Ultimate model RBK 'Sherwood'