Let me ask again since I only received one rather unsure response to my call for help yesterday. Can the 3CX800A7( and the 3CPX800A7) be operated in the horizontal position? Is it a definite no-no or just a bit risky? I am considering putting the tube into a MLA-2500 and cooling it would be lots simpler if I could mount the tube horizontally. Thanks, Bob W6TR