Hello Luis,
yes, with battery in place. That's why I was worried that it will drain it. But after a few seconds the LEDs went off anyway. This makes me wait each time before putting it into the box - I guess I am a little like the Scottish guy, who didn't believe that the refrigerator light goes off, when you close the door :-)
For me, the portability and "groundlessness" are a big plus, so the battery is essential.
My intention was not additional shielding, just thought about FR4 because it is so easy to make a box by simple soldering. But in my experience, RF circuits often start to misbehave, when you put them into a metal box. Boxes have resonances, increasing the crosstalk between distant parts of the PCB, that's why metal boxes for RF circuits are in most cases subdivided into small compartments, often stuffed with absorber foam.
How did the 3D printed box come out? The little buttons, USB connector accessibility? SMA connectors fixed with nuts?
Marko Cebokli
