Unknown EL84

[Bushbaby]

Hi All,
I purchased this EL84 in a box of mixed valves. Can anyone identify the make/manufacturer please? Its also very strange in the lack of silvering, its almost like it has none at all??

Many thanks

Rob

   

[radioman]

It looks Russian to me, not sure about the manufacturer - the first character looking a bit like a 'T' gives the game away.
I'm concerned about your description of the gettering, I've had valves like that that were going to air !
Check around the pins for any cracks in the glass...

Andy

[Bushbaby]

It was sold to me as working - I shall try on the valve tester. I always thought that they went 'milky' when there was a leak but I will bow to more expert knowledge.

Regards

Rob

[Nick]

The Russian EL84s were originally military grade valves called 6P14P (Latin alphabet) made by Reflektor in Saratov.

Current production, which should be to the same specs, is by Sovtek (now just a marketing name of New Sensor Corp - a USA business - but still in Saratov)  - there are different types/grades - the best is the 6P14P-EV which is good for 5000 hours; the "-V" is only good for 1000 hours and the plain 6P14P is rated for 3000 hours.

The main thing is that the "-V" and "-EV" are the military ones and can withstand 150 to 300 G of acceleration.

In Russian, the 6P14P series are actually called 6n14n, 6n14n-B and 6n14n-EB (Cyrillic alphabet)

[boater sam]

Used lots of Russian valves and found them to be good generally.
Gettering on some is patchy, often its at the bottom rather than the top.
I have some Russian ECH81s that seem to have practically none at all but they are fine.

If they are soft you can usually see the milkiness if you look at them with a light behind. The filament will usually burn out in a couple of minutes too.

[Bushbaby]

I have to say that its almost a tan colouring with little to no silvering. I cannot see any milkiness at all - it appears very strange!!

Regards

[Nick]

I have to say that its almost a tan colouring with little to no silvering. I cannot see any milkiness at all - it appears very strange!!

Just looks like its been running very very hot for a long time...

[Refugee]

I have an old output pentode that has gone totally clear as it slowly went to air.
The milky deposit does evaporate after time.