[Elecraft] KX2 and Heatsink

[Howard Hoyt]

>>Larry KN8N posted:
>>"I recently acquired a KX2 and use it on CW only.
>>I noticed that it does get warm.  
>>Are the aftermarket heat sinks needed?"


Hi Larry, I'm Howie WA4PSC and my company Pro Audio Engineering makes the Kx22 Heatsink for the Elecraft KX2.  The reason I make the original prototype as because when I was contesting with the KX2 at Field Day at 10W in CW the right end plate got REALLY warm.  I reasoned that as popular as digital modes were becoming this problem would be exacerbated, so a heatsink would be a useful addition to what was already my favorite and amazing portable rig.

Does the KX2 when operated out of direct sun in CW absolutely need a heatsink?  No.  Will it cut power back from 10W (or 12/15W) when operating FT8 for a while, even out of direct sun?  Yes.

If you follow Elecraft's power recommendations you do not need a heatsink, and from the Owner's Manual A5 those recommendations are:
-------------------------------------------
80-17 meters, 10 W PEP max (+/- 1 dB); 12 and 10 meters, 8 W PEP max (+/- 1 dB).
Recommended transmit duty cycle: 50%, all modes. (If power amplifier temperature or
current drain is too high, power will automatically be reduced.)
NOTE: When using over 5 W in SSB, DATA-A and AFSK-A modes, the
recommended supply voltage is 12 V or higher to minimize transmit intermodulation
products. Higher power with lower voltages should be used only when necessary.
------------------------------------------

The KX2 is a great rig, it displaced my KX3 as the go-to for portable ops.  I did install a heatsink and have not had a power reduction event since, of course for me the price was right.
I apologize to those who find this post an advertisement, but I endeavor to keep all the content factual.

Also, these Elecraft KX-series posts would be right at home in the Elecraft-KX at groups.io group where 6500+ of us rabid KX and KH fans are.  Come join us!

Cheers & 73,
Howie / WA4PSC