Noise from the Processor Board:
The processor board which the USB Connect 4G - XX is connected to may emit RF noise signals which results from the clocks of the processor as well as the data rate of digital interfaces such as USB. This RF noise may be received by the internal antenna of the USB Connect 4G - XX and therefore may limit your receive sensitivity. This may lead to a considerable lower RX-sensitivity in the down link. Therefore the following is recommended:
Ensure proper EMC-shielding of the processor board.
Noise from an active USB-Connection:
The USB-connection is a high speed data interface with a clock, which might also cause interfering RF-noise. The USB 2.0 clock noise shows up at multiples of 480 MHz since the USB clock is 48 MHz * 10 = 480 MBit/s. This type of RF-noise is quite commonly seen at 480/960 MHz on USB powered wireless devices. This might affect performance of the USB Connect LPWA in the lower frequency bands.
Therefore the following is recommended:
Ensure proper EMC-shielding of the USB-Connection.
SIM Card Access
Unscrew the enclosure of side with the label.
Lift off the enclosure halve at the front of the USB connector and then pull in the direction of the USB connector.
Now you can see the SIM card holder and open its flaps by sliding them in the opposite direction from the USB connector. You are now able to put any 3FF SIM card in the holder.
To reassemble, go backwards.