The K3560 audio output triode is unusual in that the heater runs at full mains voltage. The anode load should be 1,200 Ω and this valve can generate four Watts of output.
The K3560 was made in two versions, one for 200-220 Volts for Europe and a second type for use in America with 110 Volt mains. It is reported that 4 metres of 0.015 mm tungsten wire are used in the heater. The valves were designated for AC or DC mains.
Ostar Ganz, located in Vienna, made valves from 1932 until the late 1930's. The UK importer was Eugen Forbat.
The anode face view. It can be seen that there are two triode sections. At the base of the cathode tube the fine coiled tungsten heater wire can just be seen.
The lower end of the common anode. The start of the grid windings can beseen as can the clamp connection to the cathode tube. The fine heater wire is more easily seen in this image.
The etched information on the envelope. On the other side is Made in Austria. The voltage range is 200-220 Volts.
The classic envelope is 47 mm in diameter, and excluding the B4 base pins is 95 mm tall.
References: 1043 & 3002. Type K3560 was first introduced in 1933.