My favorite receiver used for 40 m AM broadcasts has a cracked valve, but the valve type normally printed on the glass has rubbed away. Can anyone tell me what the numbers for this valve are ?
The radio is mid - late 40's, made in Australia and has no brand or model on it.
The valve is the one audio output valve in the radio. The valve has "Philips Miniwatt Australia" printed on the black base. You can just see the crack in the 3rd picture at the lower left of the valve glass.
Clues are that it has 7 pins and they all seem connected when you look inside so 2 for the heater and 5 left over probably makes it a Pentode. CORRECTON, -> there are 7 pins but only 6 pins are connected, so i'm not sure if it is a pentode now. - It's a Tetrode.
The heater voltage is : 6 VAC. The cathode resistor is : 240 ohms. The G1 resistor is : 543 k ohms
That should narrow it down a bit.
See the pictures of the radio, chassis and valve.
You can see how clean the glass on the front dial is, that took a while to get it like that, i hardly ever clean the valves like that any more.