I’ve written a brief document about the Radioddity MU-5, including a description of the keys/functions and basic operations. The online manual (which you can find on the Radioddity web site) is much more complete, but this document may be helpful.
The document can be found here: MU-5 Notes - Google Docs
Please let me know if you find issues (haven’t really proofread it yet, nor normalized some of the terms/nomenclature). I’ll do that when I have more time.
I produced a video a while back to explain the Baofeng UV-82C radio operation. I may do the same thing for the Radioddity MU-5 when I get the chance.
Feel free to reach out via email to me (eric@swenson.org) if you need further help with your radios. – Eric