Columbus model 65 6-valve dual-wave radio.
All-world reception (dual wave), spin tuning dial, automatic 6-station push button station selector. Tuning tool to preset the pushbuttons fitted in rear (often missing).
Band selection switch has three positions, SW, BC, Pushbutton. In pushbutton mode, the tuning gang is disconnected internally. Each pushbutton is tuned with the corresponding top tuning shaft on the rear, then 'peaked' with the bottom one.
Intermediate Frequency: 464kc/s flat-top (see supplement)
Pushbutton circuitry not shown on schematic - see model 60 for details
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.