Quote:
Originally Posted by Tom9589
Not necessarily. It could be that the manufacturer just calibrated the meter accuracy under those exact conditions. 21" roundies certainly draw more current than 900 mA. Does the meter manual say that it will test 21" roundies? If so, I would expect it to put out enough current to light up the filaments.
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I can't tell in the case of his tester, but it definitely WAS the problem with my B & K 409B, even though the 21fjp22 was on the general tube list for it, and a socket was even made for it, having only 1.2A available, it could not light the heaters and the voltage dropped to about 3v.
At this point, he has nothing to lose by trying a filament transformer.
If the tube is bad / gassy, there is really no hope for it anyway, but if the tester is struggling to light up the heaters like my 409B, it will also allow his to test it w/o straining it.
EDIT..
This was a test of the roundie in the GE CTC-15 clone i got. using 3a 6.3v transformer
https://i.imgur.com/58xIKOB.jpg