Low Plate Voltage - so why the red-plating? (or red-Getter)

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Buddha's Guitar Tech
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Low Plate Voltage - so why the red-plating? (or red-Getter)

Post by Buddha's Guitar Tech »

i have on the bench an Orange Tiny Terror.

The hum reminded me of an imbalanced output section, so i tried a few valves to be sure. One of the positions also sends the valve red-plating. Maybe just 'red-getting'

Is a cathode shorting to ground?
Nope.

Turns out the OT primary is fried. One leg is only sending 8 volts....
So - why is the getter glowing? (think it's the getter, anyway)

(is it because the screens are still getting the right voltage?)

New one on me.

PS: OT leg DCR from CT - one leg, 120R, the other leg, 80K.

PPS: Oh, and char marks, as if there was any more need of proof.]
None More Black – guitar & amp repair – https://www.facebook.com/nonemoreblack
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Re: Low Plate Voltage - so why the red-plating? (or red-Getter)

Post by VacuumVoodoo »

It's screen grid glowing as it took on anode duty after OT went open circuit.
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Buddha's Guitar Tech
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Joined: Sun Dec 06, 2009 6:21 pm
Location: Larne, N. Ireland

Re: Low Plate Voltage - so why the red-plating? (or red-Getter)

Post by Buddha's Guitar Tech »

Ah, interesting.

So if i power it up with no OT, i should get the same effect in both valves i guess.
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