Hello David, The C443 is a Philips directly heated (filament)power output pentode from the early thirties. It uses the old European numbering system, the C indicates a filament current of 0.2 - 0.4 Amp, the 4 indicates 4 volt filament and the 43 indicates power output pentode. It was a standard tube used in a lot of sets of the period. The specifications are: filament; 4 volt, 0.25 Amp; Plate voltage 300 volts; plate current 20 mA; grid bias -25 volts; screen grid 200 volts; screen grid current 4.5 mA; mutual conductance (gm) 1.7 mA/volt; plate resistance 37k ohms; load resistance 15 k ohms; power output 2.8 watts at 10% distortion; grid plate capacitance 1.3 pF. It uses a European 5 pin base, looking at the bottom of the base there are 4 pins arranged in a circle with a fifth pin in the center. One of the outer pins is spaced further apart from the rest. This is pin 1 and they are counted clockwise 2, 3, 4 around from this, pin 5 is the center pin. The connections are: 1 filament+; 2 plate; 3 grid 1; 4 grid 2 (screen grid); 5 filament-. Hope this is the information you need. I think you've made a mistake with C446 in your request, I don't know of such a tube though the numbers would indicate an RF pentode if it exists. If you do have a C446 let me know and I'll look further. Don Black. PS When this tube was new Philips spelt them Penthode, the "h" was dropped later.
: Hello!!!
: Please, I have old Philips tubes C446, there are
: penthode, in which radios are used and heiter
: voltage......
: Thank you!!
: David