Hey-Hey!!!, The pentode can do quite a good job. Free from Miller capacitance issues. The g2 supply is critical, *VERY* critical I suspect. The load line must be done quite carefully so as not to run through the curves through below thte horizontal( or comparatively so )plate lines. With reasonable B+ this usually means a fairly low resistor values. 20k-40k depending on there you put the g2 voltage. regards, Douglas