The Courier model BDC was manufactured by Radio (1936) Ltd in 1937, it was in production for 1 year.

Other radios based on the same chassis:

6-valve dual-wave valve radio.

This is most likely the correct radio for this model - confirmation required - same as BDU, BDR, etc

1937 Courier BDU 'Oxford'

Technical Information

Valves (6): 6K7, 6A8, 6K7, 6Q7, 6F6, 80

Intermediate Frequency: 250 Kc/s

Frequency Bands: 2

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

Some versions appear to have been fitted with a 6U5 magic eye.

1937 Ultimate BDU Schematic

General Construction Notes for Radio (1936) Ltd:

Early Radio Ltd. schematics did not show the models, just the year, valves and bands, so some sleuthing is required to find the right one.

Early 30's Ultimate models with three digit model numbers indicated both the number of valves in the set, and the price it retailed for - for example, the model 856 was an 8-valve radio which retailed for $56 pounds. The equivalent Courier models were reversed, so an Ultimate 856 was a Courier 568 (theoretically, at least). This was the Auckland price though, and often the sets would retail for 1 or 2 pounds more in other centres, presumably to cover the freight cost of moving them around the country from the Auckland factory.

Note the use of old resistance terminology on older schematics: ω means ohms and Ω means megohms.

Some 1936-onward 3-letter chassis codes vary the last letter between brands, for example:
BBU - Ultimate model BB
BBR - Rolls (and Golden Knight) model BB
BBC - Courier model BB
All use the same chassis.

Golden Knight, Courier and Rolls appear to use the same copper-painted chassis while Ultimate chassis' are painted silver

After the war a new model code system was introduced, whereby radio models all began with R - the first model being the RA, a dual-wave 5-valve set commonly released in a pressed tin cabinet.

Other documented models using this chassis (3 in total)

1937 Ultimate model BDU
1937 Skyscraper model BDR