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Oops!

Posted by Poindexter (M) on August 12, 2006 at 11:59:30

In Reply to: This MUST be a typo - please correct it before he blows up his tubes! posted by Allen Wright on August 12, 2006 at 10:38:35:

Corrected expo to follow:

Check with an ohmmeter if the supressor (or beam plates; G3) are connected to the cathode.  If so, leave them alone.  If not, connect them to G2. In either case connect G2 to the plate with a resistor, value depending on your operating plate voltage.  Value of the resistor can be relatively small (few hundred ohms) if the plate voltage of the tube is reasonably below the 155v screen rating, should be larger (few kilohms) if you're close or a little above the rating.  My experience is that in no circumstance should you operate the tube in triode at more that five or ten volts over the screen rating, unless you like dangerous fun.

I would suggest that G3 is in fact very probably connected internally to the cathode, since I didn't see any voltage ratings for it.

Thank you Allen, that was certainly a brain fut, though I don't see at a glance how connecting all the grids together could have blown the tube up.  Enlighten, if you would; it seems to me I've seen output devices hooked up similarly somewhere

Mahalo,

Poinz

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