[Elecraft] KX3 Heatsink discussion

[Jim Brown]

A well designed output stage SHOULD be hot to the touch. The temperature 
component of protection in Elecraft output stages seems to kick in when 
the internal temperature approaches 70 deg C.  You can see this, for 
example, by watching temperature in the KPA500 and listening to fan 
speed. The function of the heat sink is to act as a conductor between 
the semiconductor junctions and the surrounding environment, and 
increased mass acts as a sort of buffer.

73, Jim K9YC

On 8/5/2017 2:53 PM, Jan wrote:
> ""I've been doing a lot of FT-8 using my KX3 and my KXPA100 at 20 watts,
> and have noticed that the KX3 is heating up quite a bit and is almost
> hot to the touch""
>
> Why should the KX3 be heating up, when the AMP is running only 20W ?
> Is the KX3 "drive" not backed-down at this level ?? HELP