Custom made Heatsink to replace the thin plate on the top of your KX3. Tests with my KX3 s/n 1722 show I can get about 50% more time key down at 10 to 12 watts before getting the “High Temp” warning and the transceiver cutting power back to 5 watts. Elecraft has stated that the “High Temp” warning will come on between 60 and 65 degrees on the Power Amp transistors, well before they are in any danger of being damaged by overheating – I just like to take extra precautions and maybe you do also. There are approx. 3.7K of the KX3′s operating and I suspect only a few have an added Heatsink. The pictures shows a sample for sale in this listing, aluminum painted black & clearcoated. You may need to make a trip to ACE Hdw and get some longer screws. I actually use BRASS screws and cut them to length for a custom fit. Also, get a good heat transfer paste like the one sold at RS for $12.99, it is surposed to actually have ground up silver in it.
I see there is some discussion on the Yahoo KX3 site about painted or bare aluminum heatsinks. I have tested both ways and there doesn’t seem to be any difference with the heat generated by the KX3 – if you don’t want it painted, I can ship it that way, just let me know.
USPS rates went up Jan. 17 and with Priority shipping to any USA address will be $56.00. For International shipping, see my ad on eBay – search Elecraft KX3 Heatsink.
Added note: The two screws that are in the middle are held in with washers/nuts – you will have to open up your KX3 to reinstall them. The two outside/end screws, self tap into the KX3.
I have actually received messages asking if the radio, a KX3, comes with this auction – so, no radio, just the heatsink!
Thanks for looking and buying.