Squealing Altinator belt '89 200TQ

[Sonar465 at aol.com]

Hey guys, I have been having a heck of a time with the altinator belt on my 
'89 200TQ.  No matter what I do it persists to squeal.  I have replaced it a 
number of times but after 4-6 months it starts squealing again.  Do I need a new 
altinator? what is going on here. My idle is set at 600RPM which is a little 
low, it seems if I keep the RPM's at about 800-850 the altinator stays 
"on-line"  I lent my manual to a buddy and I am not sure how to bump up the idle 
speed.


Cheers,
Jim