The Columbus model 44 was manufactured for Columbus Radio Centre Ltd by Radio Corporation of New Zealand Ltd in 1948.

A fine performing 6-valve (plus magic eye) all-wave radio.

This set surprisingly used a 10½" elliptical permanent magnet speaker developed out of step with the circular electromagnetic speakers that RCNZ were using in most sets at this time.

Big brother of the model 34 Oxford.  There was also a model 61 dual-wave set in this series.

In 2002, Bill Collerton of the NZVRS wrote about this model, noting that the design engineer at the time was given permission to design a small range of models using a 'modern' permanent magnet speaker (as are still used today) rather than Radio Corp's 'old faithful' electro-magnetic speaker design that had served them so well for so many years (indeed those EM speakers still sound fantastic today).  This models design introduced several other new features for Radio Corp including a tuned choke power supply (allowing the use of smaller filter capacitors) and the 6V6 output valve replacing the 6F6 that they had used for so long in so many models.

1948 Columbus model 44

Columbus model 44 'Cambridge' 1948 Columbus  model 44 'Cambridge'

Columbus model 44 'Cambridge'

Technical Information

Valves (6 + magic eye): 6K7, 6K8, 6B8, 6SJ7, 6V6, 5Y3 and Y63 Magic Eye

Intermediate Frequency: 455kc/s

Frequency Bands: 3

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

1948 Columbus model 44

1948 Columbus model 44

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.