Is it safe (for the tubes, that is) to apply hi-voltage to a tube without filament voltage? If it matters, they are 3CX800s. Mike N2MG -- FAQ on WWW: http://www.contesting.com/ampsfaq.html Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: owner-amps@contesting.com Search: http://www.contesting.com/km9p/search.htm