Other radios based on the same chassis:
5-valve model, dual-wave 5" speaker, magic eye on some
The models 24 and 25 from Radio Corporation of New Zealand were sold under at least 5 brands (Courtenay, Pacific, Stella, CQ and the newly minted RCNZ house-brand Columbus). The cabinet design was unusual and featured a symmetrical layout with the edge-lit dial on the left and an edge-lit glass plate showing Australian stations on the right. At least one Columbus model has been found in Australia so these were probably exported, and the dial would have been to give it some local flavour.
The chassis is not the usual baking pan style, but rather a more traditional welded construction, with the topside components spread to either side to make room for the centrally mounted 5" speaker. The speaker itself will likely be a Celestion (brown coloured) if it is original since Radio Corp only made 6, 8 and 10" versions at that time.
Four different cabinet variations were made, and while specific brands seem to most commonly be found in a particular variant, often they will be seen in other cabinets suggesting there was no specific cabinet for each brand - unlike the stepped cabinet designs of a few years earlier where each brand only used one of the four designs. In fact, Columbus sets have been seen for sale in all four cabinet variants in Columbus Radio Centre photos.
Intermediate Frequency: 456kc/s
Frequency Bands: 2
Chassis Notes(most schematics can be clicked to download a full size version)
Shallow / stretched chassis - not the typical baking pan style. Uses 5" RCNZ EM speaker. Some have a magic eye - known in service info as a 25E, however the chassis code appears to just be '25' on all models regardless of eye.
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). This suffix was used in the mid 50's when Radio Corp was changing over.
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. It can also indicate 'self-biased' in the transition period between back-biased and self biased sets where there were models with both methods employed (53S for example)
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).
Model nicknames are often sourced from either newspaper advertising, company literature or the NZ Radio Traders Federation official trade-in price books (Particularly Courtenay models from this publication)
In 1954, model numbering changed, to begin with the number of valves (ie: 501 - 5 valves, 1006 - 10 valves, etc) although the final 2 digits don't appear to have much significance. Middle digits of 5 (portable) or 6 (mantle, including clock radio) are used on the AWA-designed plastic-cased sets.
|1937||Courtenay model 25 'Nocturne'|
|1937||Columbus model 25 'Voyager'|
|1937||CQ model 25|
|1937||Pacific model 25|