Object
TARDIS Signal Decoder
A standalone external diagnostic device created by the TARDIS, used exclusively for decoding external control signals (e.g., Yeti Control Sphere). Unlike the TARDIS Console Fault Indicator, it is not integrated into the TARDIS console and does not diagnose TARDIS malfunctions.
3 appearances
Purpose
Detect and trace control signals from the Yeti control sphere
Significance
Equips the Doctor to probe the sphere's homing function during the violent confrontation, exposing coordinated Yeti control and prompting his sacrificial intervention; its deployment escalates the shift from investigation to tactical sabotage against the Intelligence's network.
Appearances in the Narrative
When this object appears and how it's used