G'day Tony, I've "heard" 10% of frequency. However I've also met devices which could not cope with more than about 5% in one particular direction. I vaguely recall a specification ... but if it exists it also implies that there are implementations which do not comply. ;-} -- James Cameron mailto:quozl@us.netrek.org http://quozl.netrek.org/ -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.