[CW] electric fence qrm

[rb]

Probably a tough job to get rid of that noise.  If the "ticking" sound is
regular, it's a weed cutter function of the electric fence charger.  What
they do is keep a steady state charge on the wire, but also send a really hi
voltage pulse periodically to burn off wet weeds which fall on or get across
the fence and tend to short out the lower voltage steady state charge.  They
do it with an ingenious spring loaded flywheel which rotates to close a set
of points of a second coil, and when those points break, the flywheel
recoils and the spring that is tensioned then cause a repeat of the cycle.
It does this until someone turns the thing off.  Those weedcutters will
knock a big steer on his rump.  You really don't want to touch an electric
fence with a weedcutter charger on it.