Mistyped that: 4-125A/4-400A are tetrodes (hence the '4'). 73, ian K3IMW On Wed, Jan 27, 2010 at 9:42 AM, Ian Wilson <ianmwilson73 at gmail.com> wrote: > The 4-125A/4-400A are pentodes. I notice that the 5-125B is a pentode and > has g3 > voltages specified (a sign that it's a true suppressor grid). > > 73, ian K3IMW > > >