>"Is it just for convenience? "   
      
   They want the knobs at the top. It is most logical to mount them to the   
   chassis as it IS convenient and that also provides shielding.   
      
   They could build 2 chassis' and put the "sub' chassis lower so as to   
   facilitate this but the hot air would still go up. Same difference. With the   
   sometimes very high impedances involved shielded triax could make for problems   
   with capacitance.   
      
   To the tube itself it doesn't matter, what would matter is mounting it   
   horizontally, which I would not recommend and most would agree.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)