Electrode unit

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A Dalek accesses the Mechanoid City with an electrode unit. (TV: The Chase)

The electrode unit was a device which looked like a radar dish. It could operate electronic controls remotely. It was used in this manner by the Daleks, as an alternative manipulator arm to enter the Mechanoid City. (TV: The Chase)

Jo Grant, on behalf of the Third Doctor, requested an electrode unit from UNIT's scientific supplies section. (TV: Terror of the Autons)