The Pacemaker model 5251 was manufactured for H. W. Clarke Ltd by Collier & Beale Ltd in 1951.

Other radios based on the same chassis:

5-valve dual-wave radio.  Bakelite cabinet, distinctive sweep in from each top corner. Broadcast band only model is the 5151

Badge engineered model - available in several different brands (Pacemaker, Cromwell etc) depending on the sticker on the front.

Technical Information

Valves (5): ECH42, 6BA6, 6AT6 / 6AV6, 6AQ5, 6X4

Intermediate Frequency: 455kc/s

Frequency Bands: 2

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

Gulbransen 5251 Dual Wave Schematic

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 (3 in total)

1951 Gulbransen model 5251 'Dandy Dual'
1951 Cromwell model 5251