Time flow analog
A time flow analog was a device used by Gallifreyans as a jamming signal. One could be cobbled together using various household objects.
The Third Doctor claimed that he and his friends at school on Gallifrey used to make time flow analogues to "spoil each others' time experiments."
After the Master took control of TOMTIT, the Doctor fashioned a time flow analogue out of things such as silverware, wine bottle corks, a corkscrew, napkin rings, an upturned ashtray, key fobs, and a bodkin needle. This was used to temporarily impede his continued abuse of the machine.
The people watching the Doctor build the analogue thought it was a quirky creation. Jo Grant did not understand why the Doctor was having her fetch ordinary commodities, but trusted his judgement, and Ruth Ingram initially believed it was "just a ridiculous piece of modern art". Brigadier Lethbridge-Stewart in particular found his contraption nonsensical and apparently useless, as he quickly ridiculed the Doctor when his apparatus failed to work the first time he activated it, already annoyed at being called a "philistine" by the Doctor for questioning his unusual methods.
However, Stuart Hyde offered the Doctor a cup of tea to drown his sorrows, causing the Doctor to realise the analogue needed tea leaves to work. He drank the cup and placed the empty mug on top of his analog, and this time, it began to work flawlessly. The Brigadier resigned his opinion of the device, while in contrast, Sergeant Benton was delightfully fascinated to see it work, along with the others in the room. Unfortunately, the Master soon caught on that TOMTIT was being jammed and raised its power output, overloading the time flow analog. It fried the device with a pop of sparks and knocked the tea mug to the floor. (TV: The Time Monster)
