QRP-Labs 20W dummyload

When  Hans Summer announced his QCX+ CW tranceiver I knew I wanted to buy and build one. And when he added it to his webshop I didn't hesitated for a moment and ordered the 30m kit with a few other nice QRP-Labs kits..

And after waiting for almost 2 months (Hans didn't anticipate the popularitie of the QCX+ with the enclosure), the mailman just rang once and brought me the long awaited package from #qrplabs .

Content :


  Having some time, I started with the dummy load kit and finished it within 25 minutes  


 Everything is there including 2 additional resistors (just in case). 


 First thing you have to do break the PCB in 2 equal parts. And solder the capacitor and diode in the bottom PCB. 


When you have this done,  don't forget to install the jumper wire on the top PCB from W2 to W3 (the top PCB is the PCB without any components in it yet).


Soldering every resistor one by one in the bottom PCB is quite a job, so I inserted every one of them and added the top PCB on it. Holding them nicely together with 4 x M3x40 bolts and nuts. 

I hold the top PCB under a angle and used tweezers to insert every resistor one by one.  


 Then when everything was nicely aligned, I soldered resistors to the bottom PCB.


Flipted it over, and started on the top.  


 Don't forget to install the jumper wire W0 on the top PCB to W1 on the bottom PCB (it can be easily forgotten).   


Ready for some testing.


A 3D printed case

When you are testing with this dummy load you have to look out that you don't put it on metal or have small pieces of wire laying around.
To prevent sparks and magic smoke a designed a simple 2 part case with push-pins for locking. (so you need to print 2 of them).

To honer Hans, it has the QRP-Labs logo on the bottom (or top depending on how you look at it).


Installation is easy, just place the PCB in the case and insert the 4 push pins (use a flat screwdriver to lock them in place).




I printed it in PLA, because when the PLA melts, it's to hot to handle and you outside the QRP domain  ;-) 

I made the design publicly available so you print your own but licensed it Attribution-NonCommercial-NoDerivs 3.0 Unported (CC BY-NC-ND 3.0).
Meaning : 

  • Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • NonCommercial — You may not use the material for commercial purposes.
  • NoDerivatives — If you remix, transform, or build upon the material, you may not distribute the modified material.

It's not to be childish but it now happened a few times that a 3D design I made was sold by other people just because is was "Open source, so I can do anything I want with it" without any credits or even a token of appreciation

When you want it to be used Commercial, please contact me.   

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