[TenTec] a question:

[CATFISHTWO at aol.com]

I suppose if you figure tube rigs have been around many years longer than  
solid state rig, they probably are cleaner due to less exposure  to dirt ,  dust 
and smoke.  :)
 
in truth it is just dependent on the design and amount of input and output  
filtering in the design of the amp.  You can but simple Italian  amps  from RM 
and these work 40 to 10 m and have minimal filtering and can putout a  bunch 
of garbage if overdriven.  But the ameritron als 500 and 600, the  mertron 
1000, the henry 750 and others are all FCC approved.  Elecraft is  supposed to be 
building a 1kw and a legal limit solid state amp.  
 
Now one of the best amps I ever used is the alpha 87 a and it is clean  too.
 
the key is to start with a good design, and then run the amp in its linear  
area.  tune it to peak then back it down just a tad, , less garbage, longer  
finals life and the folks on the other end will never tell the little  loss.
 
But if you have a dirty amp, please dust it before  use...:)