The Pacemaker model 515D was manufactured for H. W. Clarke Ltd by Collier & Beale Ltd in 1945.

Other radios based on the same chassis:

5-valve broadcast band mantle radio.

The first Pacemaker model released after the war, and second ever (The model 5MO was the first, back in 1940).  Released in two versions, this one and the 515.2

1945 Pacemaker 515.2

Visually almost identical to the model 515.2 although the dial is slightly different (note the 515 dial is marked up to 150 while the 515.2 is marked up to 160). 

The tuning gang in this model was mounted underneath the chassis while the 515.2 has it mounted more traditionally above.  A radio serviceman who was working when these were released recollects that these under-mounted tuning gangs were prone to be a little microphonic, so that if you tapped the radio it would become unstable - and the solution (which at first might seem counterintuitive) was to hard-mount the gang to the chassis, circumventing its rubber mounts

Technical Information

Valves (5): 6K8, 6U7G, 6Q7G, 6V6GT, 6X5GT

Intermediate Frequency: 455kc/s

Frequency Bands: 1

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

1945 Pacemaker 515.2 Schematic

Pacemaker 516A

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)

1946 Pacemaker model 516
1945 Pacemaker model 515.2
1946 Pacemaker model 516A
1945 Ensign model 515.2 'Pacemaker'