No soldering required.
I have not finished my "household items" LV serial connector thread but the first post has a link to the previous connector tab.
Finishing that connector (and the thread describing how to make it) is at the top of my to-do list right now.
I now need it for both my own K3 and for finishing up the 'debrick a DX' thread.
(The serial port is the only way to communicate with the boot loader.)