Hey. It’s because most credit cards are a bare silicon die with fragile wire bonds all potted in a hard resin. You can’t really get to the chip in order to attach a custom antenna, and the stock antenna is so fragile that most people can’t recover it.
In some cases the credit card use a Coil on Module design. If you melt those cards down they can be converted into an implant. I’m waiting to get the first one back from Amal after encapsulation, but in the near future people will have access to them.
Thanks. I knew there would be some obvious reason I missed.
If I shine a couple of thousand lumens through the card I can see the antenna running from the chip. I guess I just have to keep shining it through cards until I find one where there is no visible antenna.
If I understand right, you should be able to look for a little tiny contact on the front (circled in red) that goes from the center to the outside which is how the coil connects back to the chip as indicated in green