ULTIMATE MODEL RD (1945)

The Ultimate model RD was manufactured by Radio (1936) Ltd in 1945, it was in production for 2 years.

4-valve plus vibrator, broadcast band radio - 6-volt operation.

The was effectively the equivalent of the model RB but redesigned for 6-volt operation

Most sets found today probably have a mains power supply retrofitted, in a similar manner to the photographed model.

Technical Information

Valves (4 + vibrator power supply): 6K8G, 6S7G, 6T7G or 6Q7, 6G6G

Intermediate Frequency: 460kc/s

Frequency Bands: 1

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

1945 Ultimate RD

General Construction Notes for Radio (1936) Ltd:

Early Radio Ltd. schematics did not show the models, just the year, valves and bands, so some sleuthing is required to find the right one.

Early 30's Ultimate models with three digit model numbers indicated both the number of valves in the set, and the price it retailed for - for example, the model 856 was an 8-valve radio which retailed for $56 pounds. The equivalent Courier models were reversed, so an Ultimate 856 was a Courier 568 (theoretically, at least). This was the Auckland price though, and often the sets would retail for 1 or 2 pounds more in other centres, presumably to cover the freight cost of moving them around the country from the Auckland factory.

Note the use of old resistance terminology on older schematics: ω means ohms and Ω means megohms.

Some 1936-onward 3-letter chassis codes vary the last letter between brands, for example:
BBU - Ultimate model BB
BBR - Rolls (and Golden Knight) model BB
BBC - Courier model BB
All use the same chassis.

Golden Knight, Courier and Rolls appear to use the same copper-painted chassis while Ultimate chassis' are painted silver

After the war a new model code system was introduced, whereby radio models all began with R - the first model being the RA, a dual-wave 5-valve set commonly released in a pressed tin cabinet.