Also, the tube might be "taking off" and putting out spurious emissions. That would account for the higher grid current and the red plates. Glen, K9STH ===== Glen, K9STH Web sites http://home.comcast.net/~k9sth http://home.comcast.net/~zcomco __________________________________ Do you Yahoo!? Yahoo! Mail SpamGuard - Read only the mail you want. http://antispam.yahoo.com/tools