http://www.theworkcircuit.com/story/OEG20020828S0046
retired Italian military electronics guy (worked on
F104 and Navstar GPS)...
"Giordano explains the problem thus: Despite all
the shielding added to the signal path, the wiring
harness that links the parts combines with the
nature of the transducers on the electric guitar to
create a "marvelous antenna effect." The instrument
"can pick up any possible noise around you,"
Giordano said - from electric motors, neon signs,
transformers, electrical appliances, TVs, even
sunspots. "
"To dampen the incoming noise, tame the resulting
yawps and squeals and save time for recording engineers
who otherwise must spend hours cleaning up studio
recordings, Giordano invented an electric guitar
pickguard, composed of a full eight-layer electronic
board. A conventional pickguard is a thin plastic
covering mounted to the top of steel string guitars to
prevent scratches on the guitar body from the guitar
pick's slashing impact during normal playing. In many
electric guitars, including the venerated Fender
Stratocaster, the pickguard also serves as a removable
panel that allows access to the electronics of the
instrument. Giordano packed his pickguard with
electronics of its own. "