[Amps] 2K Classic X filament issue

[Donald Fox]

Gents:
As you may recall, I have a soft spot for the Henry Classic consoles. I recently acquired a 2K Classic X console from the original owner, and want to being it back to life. It's interesting to note that This 2KX was originally built as a domestic 2KX, with the smaller plate xformer. The owner eventually purchased the larger export 1171 plate xformer, and installed it. The amp was purchased from AES in Wickliffe, Ohio,  back in the early 80's, and used frequently until the owner left town in 1986. From then on, it sat unused for 35 years. 

After a thorough cleaning, I am seeing a brightness difference in the 3-500z tubes. I tried swapping the tubes from front to back, and the front tube consistently has the weaker filament. I have also tried a second, known good set of tubes, with the same results. A visual inspection of the underside of the RF deck revealed no obvious problems. Filament voltage is around 11 unloaded, as the filaments are in series.

I have not enabled the HV section as of yet. The bearings in the blower were semi frozen, such that a new motor was required. That part is done.

Thoughts and suggestions please. 

TIA

Don    N8ECH