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)

Although Magpie himself was killed by The Wire, Magpie Electricals survived the loss of it's proprieter, and continued to exist well past the 1950s:

• It appears when the Doctor flicks through various websites on a mobile phone. (DW: The Runaway Bride)
• 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 was not known if this was a genuine Magpie device or a replica. (DW: Voyage of the Damned)
• Wilfred Mott had a Magpie branded television, which he had when he sold Newspapers on Christmas Eve 2008. (DW: Voyage of the Damned)
• The monitor and the typewriter in the reconstructed TARDIS' console room had Magpie's Electricals brand on them. (DW: The Eleventh Hour)
• A roadblock in Starship UK has a sign saying Magpie's Electricals above it. (DW: The Beast Below)

The use of the Magpie Electricals logo is something of an inside joke of Doctor Who's design team.