[Amps] AL-1500 tuning

[George Fremin III]

I thought I would ask for some input / advice on my Ameritron 
AL-1500.  The one that I currently own does not work very well
on 15 meters.  It needs more drive on 15 meters to put out 
1500 watts and it also has quite a bit higher plate current 
when I tune it up on 15 meters.  It works as I expect on 10 meters.

I have a two radio and two amp contest setup so I usually just
try to favor the other radio and amp for 15 meters but I would
like to fix the 1500.  

I am thinking maybe the tank circuit is just not quite right
in some way for 15 meters.  What would be the best way
to check or fix this amplifier?

Thanks

-- 
George Fremin III - K5TR
geoiii at kkn.net
http://www.kkn.net/~k5tr