The 8560A is a tetrode, not a triode like the 8873, and, like the 4CX250B, can be pretty "touchy" when used in grounded grid.
Glen, K9STH
Website: http://k9sth.com
--- On Thu, 11/19/09, Richard W. Solomon <w1ksz at earthlink.net> wrote:
Has anyone tried to retrofit one into an SB-230 ?