Using the GE 12AX7 datasheet as an example...

https://frank.pocnet.net/sheets/093/1/12AX7.pdf

...I'm wondering if I am reading it correctly.

Looking at "MAXIMUM RATINGS" and "CHARACTERISTICS AND TYPICAL OPERATION", is the

**Plate Voltage**measured directly across the plate-cathode? Or is it equivalent to

**Ebb**under "CLASS A RESISTANCE-COUPLED AMPLIFIER"?

Assuming

**Plate Voltage = Ebb**. 100V should give about 80K plate resistance (in an ideal world). And looking at the 6th row in "CLASS A RESISTANCE-COUPLED AMPLIFIER", we are given the following resistor values:

Plate Resistor: 510K

Cathode Bias Resistor: 7.8K

At 90V Ebb the math gives us the approximate voltage drops:

Across Rp: 77V

Across Plate-Cathode: 12V

Across Rk: 1V

That gives us a 1V cathode bias, which equals the -1V grid voltage under "CHARACTERISTICS AND TYPICAL OPERATION" and everything is awesome.

But what confuses me is the verbiage. To me, "Plate Voltage" would be measured at the plate. Not at Ebb. I'm just looking for some reassurance that I am reading it correctly.

Thanks!