The 'cheap' 3-valve (4-valve equivalent, taking into account the rectifier) Colt
Bell Colts ran from 1951 through until 1980 - the longest running model of NZ built domestic radio. It saw many different engineering changes over the years, and the last few models dropped valves in favour of new transistor technology. There is considerable information on the main Colt page about this Kiwi icon.
The radios in this series are:
Frequency Bands: 1
Chassis Notes(most schematics can be clicked to download a full size version)
This Colt uses standard tuning... the other three-valve set (the 'Cadet') uses permeability tuning (no tuning gang, moving slugs inside coils).