[Elecraft] KPA500 Heat when powered off

[Ron Durie SIL.org]

I noticed when I covered my KPA500 with a towel, the next morning It feels
slightly warm on the bottom and top over the Transformer.  
I thought that was curious since it had been off all night.  

I turned the power switch off on the rear panel and the heat went totally away.

I wondered if there are circuits running even with the front panel power switch
off.    

I checked the schematics and T3; BRIDGE; U2; U1; U4; and other circuits are live
with the front panel power switch off.    
This is normal and to be expected given the design.  

I have concluded that the switch on the rear panel is important for removing
power totally from the KPA500.  
This is good to know when there are storms in the area, etc.  

73's  Ron Durie
WB4OOA at arrl.net  
www.durie.us