TV damper diodes are recommended in the original article, i.e., 6AU4, 6AX4 or 6X4's. The article appeared in CQ magazine, March of 1966 written by C.W.O. Joseph Dempsey- WA6JCM/4. Willy K3VW -- FAQ on WWW: http://www.contesting.com/FAQ/amps Submissions: amps@contesting.com Administrative requests: amps-REQUEST@contesting.com Problems: owner-amps@contesting.com