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Transmit or receive any radio signal from 30 MHz to 6000 MHz on USB power with HackRF.
1,991 backers pledged $602,960 to help bring this project to life.

The Wrong Inductors

Posted by Michael Ossmann (Creator)

The pilot assembly began last week.  As is typical with a new design, the process started slowly.  After setting up the pick and place machine and reflow oven, a small batch of five units was assembled by the automated process.  These units were tested in order to validate the process before proceeding with the remaining units.

Unfortunately the first five did not test well.  A few minor soldering problems were corrected, and they still didn't test well.  The units functioned, but they had terrible RF performance.  The engineer looked at the units and compared them to the hand-assembled samples I had sent, and he noticed that the inductors in the RF section looked different.  Since that component selection was a fairly late design change on my part, he suspected that my sample units were built with a different inductor than the one I specified.

He tried replacing the inductors with a vaguely similar part he had lying around, and it improved the performance.  It still wasn't as good as it should be, but dropping in a randomly selected part made things better.  The production was stopped, and he shipped me two of the new units so that I could help diagnose the problem.

When they arrived, I looked at the inductors and immediately noticed that they were unfamiliar.  The manufacturer even sent me spare inductors on tape cut from the reels purchased for the assembly, and they had already emailed me photographs of the reels.  The labels in the photos looked correct, but the part was not correct.  It didn't look anything like the genuine component that I have previously purchased from multiple sources.

Was this an intentional counterfeit?  Was it an honest error?  We'll probably never know.  The phony part has the same inductance and is the same package size as the genuine part.  It might even be made by the same manufacturer.  My guess is that it costs about 5 cents, half of the cost of the genuine part.  Is that enough of a profit to motivate intentional relabeling for an order of 20,000 units?  I don't know.

Fortunately the distributor is taking quick action to correct the problem.  They are using a known good source to supply replacement units for the pilot production as quickly as possible.  I expect that we will be able to resume production next week.

The good news is that this problem allowed me to inspect and test a couple of early sample units from the factory.  The PCBs are beautiful, and I am confident that the assembly will proceed more smoothly once the correct inductors arrive.  I will make the shipments to the PROTOTYPE backers as quickly as possible, probably by mid-April.


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    1. Frank Ruijs on

      I place my bets on the real one Michael.

    2. Michael Ossmann 3-time creator on

      If you don't mind paying more, not supporting the developer, and getting an outdated design that may have poor compatibility and performance compared to a Great Scott Gadgets HackRF One, go ahead and buy a clone. I liberally license the HackRF trademark (but not the Great Scott Gadgets trademark) similar to the the way the Linux trademark is licensed, so clones called HackRF may be legal while being unneighborly.

    3. Missing avatar

      Xie Yanbo on

      Don't know is it a good news, but the Chinese compatible hardware is already shipping now:…
      I've got one. They are using the "HackRF One" name, is that ok?

    4. Osman EL-BABA

      Thanks Michael for the detailed update and for QA on every level... Looking forward to receive the package.

    5. Michael Ossmann 3-time creator on

      Sorry I failed to get a good photo of the board. I'll try to correct that soon. My manufacturer is in China. I'm checking the other components as best I can, but most importantly I'm testing performance.

    6. Missing avatar

      Simon Brown on

      Thanks for the update. These things can happen, I'll wait impatiently...

    7. Missing avatar

      Paul on

      Thanks as always, for all the checks, much appreciated.

    8. Edouard Lafargue on

      Good thing you caught this early!

      Amazing how something that sounds obvious - ordering a specific component reference and getting that specific reference delivered - is actually a very common pitfall of hardware manufacturing. Where are you having the units assembled, by the way? You might want to double check other parts on the 5 boards and make sure you are really getting the right components w/ right tolerance for the whole BoM, if one inductor could be swapped, what about the rest ?

    9. Tiernan Messmer on

      Any pictures of the beautiful PCBs? :D

    10. Missing avatar

      Jack Glazko on

      Thanks for the details, Michael, and certainly the diligence on this. I never thought about how easy that type of problem would be to have... and what a great thing a pilot run was contracted first.

      I'm looking forward to having one of these units, but I'm very glad you're wading through the details in production as well as design. :)