Magpie Electricals

Magpie's Electricals sign, in the series 5 trailer

Magpie Electricals was a radio and television shop located on Mafeking Terrace, Muswell Hill, London. In 1953 an alien called The Wire contacted the owner, Mr Magpie, to help her get a physical body. (DW: The Idiot's Lantern)

Magpie Electricals continued to exist well past the 1950s:

• Martha Jones had a Magpie brand television in the early 21st century (DW: The Sound of Drums).
• Sarah Jane Smith's computer was a Magpie Electricals brand (SJA: The Mark of the Berserker)
• The alien cruise liner, Titanic had a Magpie-brand microphone, though it's not known if this was a genuine Magpie device or a replica. (DW: Voyage of the Damned)
• In the Series 5 trailer, there is a sign on a building saying Magpie's Electricals.