The Sontaran Field Major Styre used a transmitter base on Earth to communicate with his Marshal. (TV: The Sontaran Experiment)
The Nestene Consciousness used the London Eye as a transmitter to control plastic. (TV: Rose [+]Russell T Davies, Doctor Who series 1 (BBC One, 2005)., PROSE: Twenty-First-Century London [+]Steve Cole, Doctor Who Atlas (Puffin Books and BBC Children's Books, 2021). Page 28.)
A transmitter on Mondas sent out software updates to CyberMondans, though it possessed a limited range that cyber-units had to be within. (AUDIO: Way of the Burryman [+]Roy Gill, Old Friends (The Ninth Doctor Adventures: Series 1, Big Finish Productions, 2022).)
In Pete's World, Cybus EarPods were controlled by a transmitter from John Lumic's Zeppelin. (TV: The Age of Steel [+]Tom MacRae, adapted from Spare Parts (Marc Platt), Doctor Who series 2 (BBC One, 2006).)
During the Planetary Relocation Incident, the stolen planets acted as a transmitter for the reality bomb's energies, allowing the blast wave to extend into the multiverse. (TV: Journey's End [+]Russell T Davies, Doctor Who series 4 (BBC One, 2008).)