[Elecraft] KXPA100 Thermal Fault

[Bert via Elecraft]

I used my KX3/KXPA100 in the NAQP RTTY contest this weekend. The KX3 with  
added-on heat sink worked very well; however, the KXPA100 repeatedly faulted 
 with HI TEMPERATURE indicated on the KX3 at full output after prolonged  
operating (lots of CQ'ing with short pause intervals). PA.X temp indicated at 
 failure was around 60C...as it should. Shack temperature was around 70 
degrees  F
Yes, I know all about digital modes and full power stressing amplifiers,  
etc. What I want to know is how to mitigate this interruption yet run full  
output. To that end, I have a couple ideas: what if I mounted the amp 
vertically  so the heatsink fins "drew" cooler air through themselves via 
convection?  Secondly, would a couple muffin fans mounted atop the cooling fins do 
the job? 
The net of this is that I'd like to enjoy the full benefit of having a  
high-quality 100-Watt amplifier, regardless of mode or key-down time.
 
Bert N4CW/K1IMI