Hi, my Magnum is sitting in the corner of my room even now, ready to go! It's easy to build and still makes all but costly commercial units look silly.
It's probably still the best DIY one available, given that it uses common parts and has full instructions with PCB layouts etc.
I did a slight mod when I built mine, about 15 years ago. The plumbing pipe on mine fully surrounds the main box, with a 'T' junction below the box. This adds strength. The handle is a shaped part of this, with another 'T' that has a switch/meter box on the end. Makes it much easier to read and use.
If anyone's interested, I'll try to take a picture later and post it here. I also have the original plans (in booklet) with the extra modifications mentioned in the above site.
Cheers,
FoxyRick.