Talk:Neumann U 47

The VF14 was an RF pentode for various functions in military field radios?
Its 55V/50mA heater made VF14 unsuitable for mobile equipment; the Mullard–Philips "V" tubes were for low-budget, low-tube count ac/dc radios. 85.240.217.134 (talk) 02:24, 2 December 2017 (UTC)