[Elecraft] KX2 Heatsink [which is entirely sufficient for typical operation]

[Wayne Burdick]

Hi Kevin,

We have shipped many thousands of KX2s, and in all that time I have seen only a few comments asking about additional heat sinking.

The KX2’s thick right side panel is thermally integrated with both the top and bottom cover. This results in heat sinking that is entirely adequate  in all modes at full power, even from a 14 volt external supply. When running from internal battery (11 V), heat dissipation is further reduced for a given power level.

To put a rough number on this: I just ran my KX2 at 10 watts key-down in CW mode, into a dummy load, while watching the PA temperature (using the DISP switch function). It took well over 7 minutes for the temperature to reach the limit (63 C), at which point power was reduced automatically to 5 watts. If you persisted in operating key-down, the radio would eventually exit transmit mode. Starting temperature was 25 C (shack ambient).

Additional heat sinking might be desirable if you’re going well beyond “typical” operation: e.g., trying to run full power key-down for many minutes at a time, repeatedly, in a hot car or in direct sunlight. In that case, you have other options besides using supplemental heat sinking: reduce power, run from a lower supply voltage (like the internal battery), move into the shade, roll down the car windows, etc.

But for the overwhelming majority of our customers, the KX2’s thermal design is completely up to the task. Note that the heat sinking is intentionally designed to heat up the right end of the enclosure, so that when using the rig like an HT (holding the non-antenna end), you’ll barely feel any increase in warmth. 

73,
Wayne
N6KR



> Kevin - K4VD wrote:
> 
> From a recent post:
> 
> "We have been told by people running the rig in digital modes at 10W the
> unit will thermal down after a few transmit cycles"
> 
> I understand the KX3 also had an early issue with heatsinks that was
> corrected in time by the company making the aftermarket heatsink
> unnecessary I think? I wonder if Elecraft has acknowledged the issue and is
> correcting it for the KX2 also?