[Amps] Uneven tube glow in pair of 3-500z

[Charles Johnson]

In an L-4B amp I have just purchased, the two 3-500Zs show uneven plate 
glow at idle. Both tubes are Eimac 3-500Zs. Resting plate current is 
approx 180 ma for the pair, but one tube shows almost no color, the 
other quite a bit of color. Does this indicate overall condition of the 
tubes? At 100 watts of drive, I'm seeing about 200 ma of grid current, 
650 ma of plate current at 2500VDC, and about 1000 watts output. I would 
think that a matched pair (which these probably are not) would show 
about the same amount of color, but this seems to indicate that one tube 
is drawing more current at idle, and probably more current at full 
power. I have not tried them individually. Any ideas or comment? Thanks, 
Charles, K4ZRJ