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    the safety precautions around high voltages.

What tube is this?

I cant seem to figure out what tube this is.
It has the philips etching code, but the top row (wich indicates tube type) is unreadable.

It looks like an EF80 but the inner cunstruction is twice the size.


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EF80 Country: Europe
Brand: Common type Europe tube
Tube type: Vacuum Pentode
Tube ID = 709

Identical to EF80 = 6BX6 = Z719 = Z152 = 8D6 = 64SPT = 6P6_Magnadyne
Similar Tubes Normally replaceable-slightly different: 6EL7
Heater different: 12BX6; UF80; XF80
First year 1951 Tube leaflet collection E.Erb Analysis by original leaflets
First Source (s) Jul.1950 : Radio-Mentor # 7
Predecessor Tubes EF42 EF50 EF14
Successor Tubes 1960 EF184


Base Noval, B9A
Was used by Radio/TV-reception etc.
Filament Vf 6.3 Volts / If: 0.3 Ampere / -: Indirect / -: Parallel / series AC/DC /
Dimensions (WHD)
incl. pins / tip 22 x 68 x mm / 0.87 x 2.68 x inch
Weight 20 g / 0.71 oz
Some German EBF89 look quite different, as they have a solid grey screen. I think of them as a Siemens type, but I may be wrong. The one you have looks like a modified Philips type. I am not sure where the silvering comes from, maybe cathode activation? I don't think it is gettering, as that is at the top as usual.