Marconi valve unidentified

which type could it be?

E4 base

Filament 4 V / 0.16 A
Anode: 6 mA @ 100 V
        10 mA @ 150 V  (taken on Funke W 18)

but even at Filament 2 V / 0.085 A  it works:
Anode: 4 mA @ 100 V
        8 mA @ 150 V

any idea?

Thanks in advance,
KoBi

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Hello Konrad,

this valve is similar to the Tungsram Diode D418. As a major difference, the D418 has an anode top cap and only 3 base pins. I guess this valve was less then delighted to be operated at 150 V AC.

Best Regards, Jacob

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Thank you, Jacob.

But I forgot. it is a triode, behaving very similar to a PM1HL which is specified for 150 V max. at the anode. The question remains open...

Regards,
KoBi

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