But that is precisely where Apple hid the WiFi antennas for the cMPs - inside a dedicated heavy aluminum metal compartment on the bottom of the chassis . Not surprisingly , reception was awful .
if you turn the cMP upside down, you will notice that the bottom of the cage is made of plastic and therefore the reception is not so bad.
what apple did stupidly is to make the bluetooth antenna in the plastic frame of the PCIe access.
This has the effect that almost every USB3.0 card interferes with.
therefore i take the free cable 2 for bluetooth on devices without external antenna when converting to the combo card and connect the free one on the card with the original bluetooth antenna.