cannot read the 2013 NFC ring (or at 1-2mm) but can read at more than 1.5cm for the 2016 one, don't ask me why
3/4 cm for a badge
6/12 cm for a proximity card
The large antenna behaves strangely because it's such a poor match for the NFC Rings small antenna, yeah? You're basically having to hit one of the stronger lobes to activate the inlay, rather than having it work directly as with the smaller antenna - because of the poor match between the two.
I'm just pointing this out (and doing it here because KS comments are forever) because I noticed that it says on your campaign page that "...a big external antenna, increasing the reading range by three times! "
Looks like your connection to NFC Ring Forum was lost, please wait while we try to reconnect.