I have a all copper J-pole antenna. What is the best method to mount
it?
Can
the bottom piece (below the connector) be connected to a tv mast with
clamps?

Yes... you can ground the antenna, in fact,
it is recommended.
__
Steve
KI5YG
.

Copper J-pole mast-mounted alongside chimney works extremely well for me on
vhf-marine. Mine is grounded with insulator-supported #4 solid copper wire,
not for antenna performance, but because it more than just resembles an
air-terminal / lightning rod! Because I use heavy feedline, there are no
decouping-loops just under the J-Pole as recommended by most designs. So if
my feedline is radiating, it doesn't seem to hurt the maximun distance I
obtain with that antenna. It works very efficiently far beyond the
theoretical radio horizon.

Jack
Oceana Radio