Thanks 'yall, for the ideas. The belt is not slipping and is quiet, the tensioner has not been replaced lately, however, the voltage output would simply fall off to somewhere near 12.7,at RPM's above 2500 and when the RPM's fell back below that number, the voltage would "hop" right back up to around 14."something". We just took it off and put it back in the box and are condemning the internal voltage regulator component of the alternator as faulty.
Thanks again....Peace