COLUMBUS MODEL 515 'CHALLENGER' (1957)

The Columbus model 515 was manufactured for Columbus Radio Centre Ltd by Radio Corporation of New Zealand Ltd in 1957.

5-valve broadcast mantle radio, available in 5 colours. Sighted ivory, grey, blue and burgundy. Fifth colour is?  Brown?

Two different dial glasses - both with red insulated wire strung across the face of the dial drum and soldered in place at each end as a pointer. 

Note: blue set photographed has been resto-mod'd and pointer is now yellow while cabinet is painted to deal with cracks - the chassis is restored to factory.

This set is similar to the Astor / Columbus 525 and the Astor FEU

Valves (5): 6BE6, 6BA6, 6AV6, 6AQ5, 6X4

Intermediate Frequency: 455kc/s

Frequency Bands: 1

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

NB: Some sets are IF-peaked at 465kc/s as per note below

1957 Columbus model 515 IF Peak Notes

1957 Columbus model 515 Schematic

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.

Model codes beginning with a 0, for example the model 051, are Osram valve versions of the model without the leading 0. Technically the 0 should be an O (for Osram), however the digit 0 was used throughout the site before this fact was discovered.

The E suffix indicates a magic eye option is fitted (in models which were available with or without, such as the model 25).

A and B suffixes appear to be simply updates to the current model, R also appears to be simply an updated model ('R'edesign, perhaps?)

P indicates either a permanent magnet speaker version of a model which also came with an electromagnet speaker (the model 26 for example), or a portable model (like the model 694P).

N and M indicated miniature valve versions of a model which started with all (or a mix, ie: model 5) of larger valves. One of these two codes may indicate a transitional mixture of octal and miniature - clarification is required.

S often indicates a stereo model.

Finally, other suffixes and prefixes make occasional appearances in the RCNZ lineup - like the 66W (a variant of the long-running model 66) and the 75XA (a 10-valve version of the model 75 with a separate amplifier chassis).