The Ekco model RDM was manufactured by Radio (1936) Ltd in 1959.

Other radios based on the same chassis:

The Ekco Transistor 8 'Stroller'.

Assuming its functional, wiring in a 9V battery or a 6 x AA (or C or D) battery holder to give 9V should get one of these up and running.

1959 Ekco RDM 'Stroller'

Technical Information

Valves (8 Transistor ,1 Diode): 2N544, 2N412, 2N412, 2N412, OA85, OC71, 2N406, OC72, OC72

Intermediate Frequency: 460kc/s

Frequency Bands: 1

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

Modifications Document RL-RDX-RDZ-REC-modifications.pdf

Chassis code RDM - this might not be visible on the chassis but is documented in the schematic.

1959 Ultimate RDM Parts List

1959 Ultimate RDM Schematic


These notes are for the Ekco version, note the inconsistent IF frequency of 470kc/s instead of 460 as shown on the schematic - it would pay to check the IF before re-tuning.  Also note the other mistakes as indicated.

1959 Ekco RDM 'Stroller'

1959 Ekco RDM 'Stroller'

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.

Other documented models using this chassis (2 in total)

1959 Ultimate model RDM 'Explorer'