Mark, its only a ground rod. Just spring for a new one and replace that wire
while you're at it along with the clamp. Its not going to cost much and what
you'd have to spend to insure that the old one was good would be prohibitive.
Tom
Tom Brennan KD5VIJ, CCC-A/SLP
web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html