Cooler KX plus heat-sink

The Cooler KX plus heat sink installed 
From my previous posts my readers know I am now in the process of delving back into the digi modes with my Elecraft KX3. With the digi mods there are long duty cycles and thus the PA's in rigs sure do get a "hot" workout. In the KX3 if the heat goes to a certain point the power is rolled back to not damage the PA's in the rig. There are other events that can cause the rig to roll back power but operating in the digi modes is sure high on the list. Not wanting to operate on reduced power and not to say bringing the rig to this point really can't be good for it I have a choice operate a lower power or find some way to keep the finals cool. The heat sink on the KX3 is good but not great and therefore a
Cooler KX plus compared to stock
product called Cooler KX comes into the picture. This is a very easy upgrade to the KX3 and has been designed to not take away from the KX3's styling. The company is Canadian and Fred VE7FMN has done a very professional job on adding extra cooling ability to the Elecraft KX3. There are 2 heat sinks that are offered and they are the Cooler KX lite and Cooler KX plus. I ordered the Cooler KX plus and am very happy with my purchase. Once I placed my order Fred was in contact with me via email asking very important and clarifying questions to make sure my installation went without a hitch. The heat sink arrived very well packaged and with all the hardware needed for a trouble free instal. The instructions that came via email from Fred were very well layer out and easy to understand. I am never excited when ever I have to take apart either my Elecraft K3 or KX3 as this is the time things can get damaged. The heat sink upgrade is fairly straight forward and easy to do compared to let say the sub-receiver addition to the K3 now that to me was a nail biter. The heat sink instal involved removing two nut and bolt configuration to release the
Two PA's fastened to heat sink 
two PA's from the heat sink and then 2 more screws that secure the heat sink to the radio. It was basically the reverse to instal the new heavy duty heat sink from Fred. If you own an Elecraft KX3 I would recommend this upgrade as no matter what mode you are operating in your PA finals will be cooler and thus a longer life for the KX3.
Mike Weir, VE9KK, is a regular contributor to and writes from New Brunswick, Canada. Contact him at [email protected].

5 Responses to “Cooler KX plus heat-sink”

  • Rob W8MRL:

    I’m curious (I don’t have a KX3)did you use a thermal paste like what is used to enhance conduction between a CPU and it’s heat sink? A top grade silver thermal paste should really enhance heat transfer.


  • Kyle N4NSS:

    The paste is not recommended, per the MFG.

  • mike VE3WDM:

    Yes Rob Kyle hit the nail on the head…in the install instructions the paste is advised not to be used. The way I read it is using the paste could cause other problems with using to much and also using certain pastes that can cause problems on the heat-sink. The impression I get is the heat sink on it’s own works great without the paste and you could cause some problems with using it.

  • mike VE3WDM:

    Kyle, thanks very much for the input and it’s what I really like to see interaction of hams on the post.

  • James WX4TV:

    Thanks for the post, Mike. The kids received a Cooler KX Plus™ for Christmas and 10 year-old Hope (KM4IPF) learned how to install it yesterday with a little help from Daddy. She made a video and posted it to the kids’ YouTube channel,

    Listen for the kids on the air either with their own callsigns (WX4TVJ, AE4FH, KM4IPF, or KM4TXT) or with the family club callsign of WK1DS!

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