The question keeps coming up, about the radios called QCX-uSDX (and other such variants of name) on eBay and elsewhere:
Are these QCX "clones"?
NO! They are NOT clones of the QRP Labs QCX-mini 5W CW transceiver (see http://qrp-labs.com/
The QCX transceiver is a high performance 5W single band CW transceiver, designed by Hans G0UPL and produced by QRP Labs. It is NOT open source. QRP Labs is a commercial venture and all software, designs and hardware are proprietary to QRP Labs. Copying in whole or in part is illegal. If you see any QCX clones anywhere (eBay, AliExpress etc) please inform us.
uSDX is an SDR transceiver that was originally developed on the hardware of the original QCX http://qrp-labs.com/qcx by Guido PE1NNZ. Later work by Manuel DL2MAN encouraged more interest and the uSDX spun off into its own separate project, with its own discussion group at https://groups.io/g/ucx. uSDX is not affiliated with QRP Labs or supported by QRP Labs. uSDX is an independent open source project. The radios being sold on eBay, AliExpress etc are versions of uSDX. They aren't "clones" because uSDX is open source and any productions of the radio by anyone are legitimate. Having said that, you may question what quality and support you will get. If you look at the uSDX group https://groups.io/g/ucx you will see quite a bit of discussion about this recently including opinions on these particular radios you mention so please take a look there.
The uSDX project was originally called QCX-SSB by Guideo PE1NNZ because he made some hardware modifications to QCX and wrote his own firmware. His github page still has this "QCX-SSB" on it, and since some of these eBay sellers have ignorantly copy-and-pasted, "QCX" appears in the title... which does cause some considerable confusion... since they are not QCX. The word "QCX" should not appear in the title since it is totally inaccurate and misleading. But try telling eBay sellers that...
The uSDX, and particularly its eBay implementations, are not a high performance transceiver. It's very clever technical work by PE1NNZ and subsequent developers, but it has significant performance limitations due to the low CPU power available in the ATmega328 and the limited resolution of the 10-bit ADC in the ATmega328. The eBay implementations also often suffer inferior components and poor design choices which are not compatible with the original uSDX design.