Bil wrote:
After checking my zinc anode, I'm fairly certain I'm getting
accelerated erosion of my shaft zinc anode when transmitting Sailmail
e-mail via my HF radio and PacTOR modem.

Sailmail and the PacTOR modem drive the HF radio (an ICOM IC-M710)
fairly hard.

Does everyone transmitting with a PacTOR modem suffer accelerated
erosion of their zinc anodes? Or is this something specific to my
installation (and can be corrected)? If the latter, what should I look
for and correct?

Cheers

Bil

Look at

http://www.sailmail.com/grounds.htm

Probably the best article on grounding available
Gordon