128 CV4060 / S11E12 STC UK Military CV4060 / S11E12 STC UK Military octal 85000 A$27.50 120 gram http://www.retrovox.com.au/Images/s11e12stc150.jpg CV4060 / S11E12 Special Quality Beam Tetrode STC/ITT CV4060 / S11E12 Designed late 1950s for use in series or shunt control circuits. The S11E12 has an international octal base and the important parameters are as follows: Heater Voltage Vh 6.3 volts Heater Current Ih 1.6 amps Anode Voltage Va (max) 800 volts Screen Voltage Vg2 (max) 300 volts Mutual Conductance gm 13.5 mA/V Anode Dissipation Pa (max) 28 watts Cathode Current Ik (max) 300 mA Specially designed to resist shock and is quality tested at all stages of manufacture to ensure maximum life expectancy. Full data for S11E12 available in 350K pdf document thanks to Frank Philipse. Go to Frank"s S data page Pinout differs only in one respect to KT88 / 6550 types: Pin 6 is connected to the beam plates. For use in existing KT88 / 6550 applications connect pin 6 to pin 8 at the socket and do not use pin 6 as a tie point. Retrovox stocks STC 1970s/80s CV4060 / S11E12. For further info see http://tdsl.duncanamps.com/show.php?des=S11E12