BELL COLT 'MAIN INFORMATION PAGE' (1951)

The Bell Colt was manufactured by Bell Radio-Television Corporation Ltd in 1951, production ran for 30 years.

The Bell Colt was the biggest-selling, longest-running and arguably the best known model of valve radio ever designed and built in New Zealand. The ubiquitous Colt spanned almost 30 years and saw several different chassis versions with 3, 4 and 5 valves, and three different transistorised models (including a battery-portable Colt) for the last few years of production.

Cabinets
Along with different circuitry, there were many different dial layouts, at least 7 cabinet colours (with various tones of colours as well) and even some different cabinet styles including a light- and a dark-toned solid oak cabinet being offered.
Airzone Cub - The cabinet used for the Bell ColtThe plastic cabinet dies came from Australia where they were used for the Airzone Cub (as shown to the right), just as the previous Bell mantle, the 5E (and the Antone Cadet - or was this the same model with a name change when the company name changed?  Information would be appreciated), had used the ornate but fragile Airzone 458 cabinet.
You can see the mold marks for the Airzone logo mounting area on most Colt cabinets (behind the middle knob) although there are some cabinets where this is not visible at all suggesting that either new molds might have been made (they do wear out over time) or the original molds may have been modified to hide this.

original cabinet late modifications

The later model cabinets are modified from the early designs and this can be seen in the molding between the dial and the grill, where both sides of the horizontal fluting is edged and the braces in the grill are more substantial.  Inside the cabinet used on the very last model (Solid State COLT Mk III) there are screw holes to mount the PCB and Plessey speaker.  All of the mains-powered transistor sets also have both top corners drilled so the back panels can be mounted.

Knobs

short-shaft chassis long-shaft chassis

There are also two different lengths of control shafts - the short-shaft versions only extend to be just beyond flush with the cabinet and uses push-on plastic knobs.  The push-on knobs can be an absolute nightmare to remove as they seem to glue themselves to the shaft over time, and often must be broken off as there is no easy way to get in behind the sleeve section of the knob to try and help release it.  This style of knob was not common on other sets either, and as a consequence its quite common to see bell Colts for sale with one or more broken knobs.

The long-shaft version uses a traditional grub-screw mounted molded knob. It is common for these knobs to crack, most likely due to overtightening as they have no metallic sleeve inside and just rely on the strength of the plastic.

These are not the only two styles of knob fitted to Colts, with the ones on the left being another common example.  Many arguments arise as to what knobs a Colt SHOULD have, but so many of these sets were produced over the years (around 160,000 in the first ten years alone, that's nearly half a million knobs not counting the world-wave models which needed one extra!) that it seems reasonable that the factory would use whatever it had (or could get) if-and-when it ran out of one type.  Indeed anecdotal evidence from ex-Bell employees backs this up.

Variants
Over the years there were many different variants in the family of radios all now known as 'Colts' - Many were not referred to as a Colt at all, but all models in the well-known plastic cabinet and those in similar timber cabinets with the same chassis' have come to be included in the legendary 'Colt' lineup. These are the ones we know about from sales brochures, trade price lists, JWS' books and old copies of the Listener. Please feel free to help update this list if you know of others.
 

MODEL CODE YEAR RANGE SERIAL RANGE (approx) NOTES
Original Bell Colt 1951 0 - 1200 no model number on chassis, all rimlock valves.  Includes Rolax branded Colts
5B4 Colt 1954   5-valve, first to have a model code stamped on the chassis (only some?)
5B5 Colt 1955   5-valve, last to have a model code stamped on the chassis (only some?)
5B7 Colt 1957   5-valve
5B60 Colt 1960   5-valve
5B61 Colt 1961   5-valve, late models had bridge rectifier replacing rectifier valve
5B67 Colt 1967   4-valve + bridge rectifier - Last of the valve-based Colts? running until 1972?
5W7 Explorer 1957   World-wave (BC + SW)
5D5 Planet 1955?   Solid blonde or dark oak cabinet
5B7 Venus 1957?   Walnut Veneer
3B7 Champ 1957?   3-valve
3B8(?) Cadet 1958?   Permeability-tuned 3-valve
All-Transistor 1967   7-transistor battery portable Colt
Solid State Colt 1967-1971 appr.   Transistor mains Colt
Solid State Colt MKIII 1971-1980 appr.   Transistor mains Colt - last ever model produced

 


Other Brands
The Bell Colt was also produced as a Skymaster model for Bond and Bond, a Rolax for Sedley & Wells Music Centres in Christchurch and even a 'marine' version of the dual wave chassis (without tone control) was released by Fountain. In 1962 when Bell dropped the Colt in favour of its new 'General Radio' line, Tee Vee Radio Ltd took over production as the 'Tee-Rad Colt' for a couple of years, however they were not successful and production went back to Bell.  An advert publicising this manufacturing switch states that the Colt would appear identical and so its not known if there is any way to tell the Tee-Rad Colts from the Bell ones - any information on this subject would be gratefully received.

 

Valves (3, 4, or 5, or Transistorised):
Various (model dependent):
5B4: ECH41 or ECH42 or ECH81, EF41, EBC41, EL41, EZ40
5B60: ECH81, EF89, EBC81, EL84, EZ80
5B61: Same as 5B60, although later variants had a solid state rectifier
5B67: ECH81, EF89, EBC81, EL84, BY179 Silicon Rectifier

Intermediate Frequency:
Various (model dependent):
5B4: 462kc/s
5B60: 455kc/s
5B61: 455kc/s
5B67: 455kc/s

Frequency Bands: 1

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

Bell Colt chassis numbers hint at that particular variants year of introduction: 5B4=1954, 5B60=1960 etc - however chassis codes are generally not indicated anywhere on the radio except for some 5B4 and 5B5 models (details of the 5B5 are undocumented at this stage) where the code is stamped into the top left hand corner of the rear plate of the chassis as shown here.


Generally some detective work is required to figure out what model you're dealing with - check the number of valves, the types, the chassis layout (which is shown on some schematics) and other telltale signs.