[Amps] Weak Amperex 3-500Z

[Keith Dutson]

Last night during a weekly practice session with our ham club's small
bluegrass band, one of the guys said he replaced the Amperex 3-500Z in his
AL-80A.  It was putting out about 400 watts CW.  He replaced with a 3-500ZG
from RF Parts and now gets 800 watts CW.  I asked what he did with the weak
tube and he went into the shack and gave it to me.

Is there anything that can be done to rejuvenate the weak tube?  Or, is it
just worn out?  I don't think it has ever arced over, and I can see no
external marks on the plate.  What happens to make a tube weak?

Thanks in advance for all advice.

73, Keith NM5G