Cecil Moore wrote:

During AZ desert
windstorms, this new G5RV of mine arced at the coax
connector due to precipitation static, sometimes several
times per second.

Hi Cecil -
Just a small bit of elaboration on your point - the arc is the result
of the accumulation of a sufficient amount of charge to facilitate an
electrical discharge in air. Static is heard in the receiver as the
charge is being acquired, but an AGC limited pop would be heard when
an arc occurs. (And sometimes nothing at all after the latter :-)

Putting up a 40m folded dipole caused
the arcing to cease.

That's right. The accumulated electrostatic charge would be
distributed uniformly along the length of such an antenna. Both ends
of the antenna would therefore be at the same potential, so there is
no propensity to arc across them. If at least one of the antenna
terminals on the rig is grounded, the likelihood that the antenna will
accumulate a significant amount of charge is greatly reduced. The
antenna is still just as likely to produce precipitation static noise
however. If the receiver input was strictly differential, then it
would indeed be completely insensitive to common mode signals and noise.

73, ac6xg