LF: Local AM transmitter on PC output

["Andy Talbot" <andy.g4jnt@googlemail.com>]

While testing an IQ upconverter chip, I discovered I've got several
tens of millivolts of Virgin AM on 1215kHz coming out of my PC's audio
output.  There is enough signal to see it on a frequency counter and
view the AM on a scope.

There is presumably a transmitter nearby, and/or some curious
resonance in the house wiring that accentuates pick up of this signal.
Its not the LF antenna picking up the signal, so I'm wondering if the
ring-main is forming a resonant loop :-)

Does anyone know where the transmitter site for this station is located?

Andy  G4JNT
www.scrbg.org/g4jnt