The very first portable transistor set by Columbus. 7 transistors, available in several colours.
This model was updated the following year and released as the 117PZ - both models look very similar, however the 897 has 'Columbus' either side of the dial hub and a white plastic 'button' shaped Columbus logo on the grill, while the later 117 model has 'Columbus Transistor' on the dial and a more elaborate gold-coloured Columbus logo on the grill.
This series contains all the known Columbus portable radios - including a few transistor portables from the final few years of the brand.
The radios in this series are:
Valves (7 transistors, 1 diode): 2N219, 2N218, 2N218, OA150 Diode, OC602, OC602, ( OC604 x 2 Matched Output Pair )
Intermediate Frequency: 455kc/s
Frequency Bands: 1
Chassis Notes(most schematics can be clicked to download a full size version)
As this was the first transistor set they had produced, Radio Corporation of NZ released a very comprehensive set of documentation to explain its operation was provided to Columbus Radio Centres.
Note the standard looking output transformer - the later 117 has an old-style oval can enveloping its output transformer. Also note this model has one control on the side, while the later 117 has two.
This was the only transistor set from Columbus which used European 'OC' coded transistors, the following models all used RCA '2N' coded types.
Columbus model 897P 7-Transistor Portable - Advance Technical Data here
Columbus model 897P 7-Transistor Portable - Service and Supplemental Data here
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.