Don, if you're facing the back of the rig its on the left side on the lwer edge
to the right of the reset. Its the only 1/8 inch jack back there so you
shouldn't have any trouble confusing it with anything else.
Tom
Tom Brennan KD5VIJ, CCC-A/SLP
web page http://titan.sfasu.edu/~g_brennantg/sonicpage.html