Debugging QCX issues, using cheap pocket scope, DVM or built-in DVM. With 40m QSO at the end

I bought this low cost DSO150 ("DSO Shell") pocket scope from AliExpress for under $20 incl shipping.
This video is about debugging techniques for when your QCX construction didn't quite result in a working QCX. The methods described and demonstrated with the cheap 'scope are also applicable to more advanced 'scopes.
Also shown, are how to use a cheap DVM, and even the built-in DVM on the QCX, to carry out debugging of the Receiver section.
Finally I transmitted some CQs on 40m CW and after the third CQ, had a nice QSO with Nick LZ1NG.
QCX is a 5W CW transceiver with very high performance, lots of advanced features and built-in test and alignment equipment. It costs only $49. See qrp-labs.com/qcx for more information.

[@Curamach42]

You're right about the header. I blew up my QCX 20 messing around near it. Built a QCX 40, found two missed solder joints. Now it works great and I've made many QSOs. I have poked around it with my new oscilloscope (9 volts for some cushion of safety.) I have learned a lot. My order for a QCX+ 20 is in. This is great stuff. Thanks Hans, 73 Dan KF4AV

[@Steve-GM0HUU]

Thank you for this video Hans. I found it very informative.

[@Liberty4Ever]

Thank you for the video. I'm looking forward to your QSX kit.

[@arnet3575]

Thanks! I start building my QCX-kit today, so this video came right on time for me (if it doesn't work instantly).

[@arvsupr2354]

Very informative video. So helpful, I intend watching it again, and making some notes. Good to see the QCX under operating conditions too. Thanks for a ‘fun to build’ kit with excellent instructions. My first foray in HF. GM1BUY

[@jertres2887]

Thanks, useful informative & educational.

[@russ_vee_jr4199]

This procedure is applicable to all three QCX models. (QCX/QCX+/QCXmini) They all use the same schematic/firmware.

[@mikesmithg0rfd356]

thank you

[@prestonshute7243]

Thanks for this very informative video. I’m sure it will be an excellent aid for those folks having a problem with this great kit. 73 wd4dda

[@stationvictormike3415]

On that 2X3 header, I placed a piece of electrical tape around it for protection.

[@aurtisanminer2827]

Anyone know how to tell which pin is what number? I’ve only been able to find one diagram of any of the chips on the board and it’s of IC2.

[@aurtisanminer2827]

Nevermind, I found some pinouts online. Looks like they’re in the same order as IC2.

[@radioastronomy2001]

Is there a way that you could produce a VHF (6,4,2,1.25m) version of this device? There is really nothing affordable on the market.

[@wb6csh]

Your audio is WAY TOO LOW! Why are you whispering?

[@on4mgy_radioamateur]

Great video, thanks for sharing Hans, 73 de ON4MGY Nic