The Columbus model 84 was manufactured for Columbus Radio Centre Ltd by Radio Corporation of New Zealand Ltd in 1938.

5-valve broadcast-band only - at least two different cabinet designs as seen below, one using an atypical (for RCNZ) woven metal grill.  Note, the advert below refers to the Skipper as a dual-wave, however the dual wave version of the model 84 is the model 85, and has 4 knobs so this is a misprint.

1938 Columbus model 84

Valves (5 + eye): 6A8, 6K7, 6B7, 42, 80 (and 6E5 magic eye on some models)

Intermediate Frequency: 456kc/s

Frequency Bands: 1

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

5-valve chassis, a similar (reasonably basic) design to the model 24. A magic eye is included in the schematic, however it is not always fitted

General Construction Notes for Radio Corporation of New Zealand Ltd: The first digit of the serial number typically indicates the year of manufacture of RCNZ chassis' (although not the decade - that requires a little knowledge of the valves, construction, etc). Sets from around 1934 onwards were often (but not always) constructed in a distinctive pressed 'baking pan' style chassis, seemingly unique to RCNZ.

All documented models using this chassis (2 in total)

1938Columbus model 84 - this set
1938Courtenay model 84