[Henry] 3B28's burning time???

[Milton Valerio]

Hi to all, ok after replacing the resonator capacitor on my 2K I turned on with the HV cable disconnected from the RF deck to prevent HV enter to the PA plates.
I see the 3B28's working and the AC to the plates is V3000, rectified voltage is DC3000.
Anyway, I note that in one of the tubes a long continuos light blue spark is present and a slight buzz is heard. I ignore if this condition is normal, also I was expecting a more colorful purple on the tubes but actually is almost inexistent such color.
I heard about a certain period of burning time when 3B28's are NOS so I dont know if that's correct or not, these tubes are new from the box.

Milton