[TenTec] Plate Voltage reading on Centurion

[john]

Hi Everyone,
My trusty Centurion (which will still pump out rated power on 20m without a 
great strain) seems to have the plate voltage dropping to what reads now ~ 
2400V. Since it was at TT less than a year ago with a good bill of health, 
I doubt the electrolytics are failing, especially since the amp seems to be 
making full power (though I rarely run it that hard).

Is the meter shunt known to go bad on this ?  I do have a Fluke HV probe 
for my 87 and am capable of measuring it safely.  I'm guessing TT still has 
the shunt itself should I need one.

Thanks for any info
John k5mo