The dongle can receive RF signals (and noise) in the range of about 24 MHz ~ 1800 Mhz.
To check noise picked by antenna in this range, unplug your dongle from RPi, plug into a Windows computer (with antenna connected to dongle) and run following scan:
Spektrum - How-to Speedily Scan RF Noise in band 24MHz ~ 1800MHz
Below are scans at my urban location with lot of Cell/mobile antennas on top of my building and adjuscent buildings, as well as many strong TV & FM stations.
Scan 1 of 3 - FA Antenna + Generic DVB-T (no internal or external filter)
CLICK ON IMAGE TO SEE LARGER SIZE
Scan 2 of 3 - FA Antenna + ProStick Plus (Only Internal filter of ProStick Plus. No External filter)
CLICK ON IMAGE TO SEE LARGER SIZE
Scan 3 of 3 - FA Antenna + ProStick Plus (with internal filter) + External Filter (FA Light Blue)
CLICK ON IMAGE TO SEE LARGER SIZE
