[Elecraft] KX3 running warm even at very low power out

[Brian Hunt]

During transmit your PA current will increase even with no power out due 
to biasing of the final PA devices.  On my KX2 current draw goes from 
135 mA (RX) to 500 mA (TX) just by hitting the XMIT button but with no 
key down.  Over the 2 minute TX cycle of WSPR that will heat up the heat 
sink a bit.  But that's normal.  HTH

72,
Brian, K0DTJ

On 12/6/2018 12:50, Mike Parkes wrote:
> I have been experimenting with WSPR mode at 2-10 milliwatts of power out as
> measured by the WM-2 wattmeter. I notice that the back of the KX3 heat
> sinks are still fairly warm to the touch at such low power. It surprises me
> that the finals would still get that warm at this level of power out. Is
> that normal? I don't want to damage the radio tryin mg to xmt very low
> power! :)... I have nothing to compare to except it feels at least as warm
> as it did at 1 or 2 watts out. (I am using the power level output from
> WSJT-X to set the power out to levels lower than what the KX3 can show
> which is limited to 100 mW.)
> Mike AB7RU
>