[Elecraft] K3 Heat

[Jim Brown]

On Fri, 15 May 2009 09:14:50 -0700 (PDT), Hisashi T Fujinaka wrote:

>Well, you're all ignoring the longevity reduction with heat. 

I'm certainly not, and I doubt that the designers of the radio have 
either. K6XX, an engineer who has looked carefully at the design, 
considers it very well designed from the point of view of heat and 
ventilation. The lead engineer is the same guy who designed the 
K2/100. They've sold close to 7,000 of them, and I've never heard 
of a problem with heat. 

Those who talk about cutting holes to "help" ventilate the radio 
are probably forgetting the very well controlled heat flow that has 
been established by the design. One side of the radio runs warm 
because it is the heat sink for a couple of transistors. The bottom 
of the chassis runs warm because it is a heat sink for the driver 
transistors. This is very solid EE design. It is NOT indicative of 
a problem, or of operation that will cause premature failure. 

If you want to be super conservative, set up a small muffin fan to 
blow cool air on the radio. And, of course, calibrate the 
temperature sensors properly. But don't mess with the design. 
There's far more to it than meets the eye, especially the eye of 
someone who isn't an EE with this sort of design experience under 
his belt. 

73,

Jim Brown K9YC