Although I think just about everything has been covered here, one fairly
important point remains.  "Not all fence chargers are created equal."  We
discovered this a number of years ago.  Some models give you a strong
initial output, but handle little resistance (i.e. a 200 lb bear on dry
ground felt nothing after the first "twing" if he continued to challenge).
New Zealand and Austalian companies gained a lot of ground here in the late
seventies, because their fencers were designed to handle a mob of sheep all
contacting the wire at once.  What a difference.   PEL, Gallagher, &
Speedrite are all excellent imports.  "Some" North American Companies have
risen to the challenge now.  The ones I know to be good are Parmak &
Striker.  "Clean," unimpeded readings tell you nothing, what will it do
under load.
 
Solar Panels give peice of mind (Avoids "I forgot the replacement battery"or
"Is this battery getting old? It was good for four weeks last time.").
 
We no longer use sardine cans unless we have a location we are fencing after
an attack.  We felt they were attracting critters that may not have
otherwise come to the yard (ex. Skunks always seemed worse in those
locations with cans on the fence).
 
Finally, I am told there is a new product on the market called a "Critter
Skidder"(or something close).  It is battery operated and emmits a high
pitched scream when it's motion detector is activated.  It is supposed to
have a range of 20-25 feet. I should be getting more info soon and will post
it then.
 
David Tharle
Ardmore, AB