Hi Jim,

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The 36 percent higher current is certainly a head-scratcher,

but there are tests for carbonized filament tubes. Some I know:

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Filament resistance cold -vs- Filament resistance warm (Good DVM).

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High Voltage HIPOT, various pins to various pins.

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Emissions Test with a calibrated load and calibrated

Plate Current ~ Grid Current.

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Stack all this up against a known good tube with the same

sort of testing. If results are whacky (As in “Tabaccy,) use

a third known good bottle.

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Somehow, somewhere a performance statistic will result.

A known dud is a possibility, even.

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Maybe the tube in question suffered a minor Funderberg

occurrence, like a fission reactor, it might have had a

small “excursion.” And now the Piper is calling. Looking

for that gold sputtering deposition on the filament strands,

perhaps.

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Give her a whack straight down on a hard surface, once, and

see if the DC resistance changes ever so slightly.

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Your view?....

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Hal

W4HBM