RFExplorer Detailed Scan
The RF Explorer is limited to 112 steps in a frequency sweep. When coordinating a larger frequency range, the resolution bandwidth (RBW) becomes larger and imprecise.
This script helps create scan datafiles with a lower RBW by breaking the sweep into smaller chunks and "stitching" them together for a final dataset. It connects to the RF Explorer over its USB interface and produces output files on the host computer.
Presently, only header-free CSV files are supported output -- suitable for import into Shure Wireless Workbench.
Here is a video demonstrating the installation and usage of this script with Shure Wireless Workbench.
sh build.sh
# in Linux/macOS/etc:
source venv/bin/activate
# in Windows:
source venv/Scripts/activate
Usage: rfexplorerDetailedScan [OPTIONS] OUTPUT_FILE
Options:
-p, --serialport TEXT Serial port (None to autodetect)
-b, --baudrate INTEGER Serial port baud (default 500000)
-s, --start-freq INTEGER Scan start frequency (MHz)
-e, --end-freq INTEGER Scan end frequency (MHz)
-r, --step-resolution INTEGER Subdivide full spectrum into this many MHz
(112 steps per)
-i, --iterations INTEGER Ensure at least this many sweeps run of the
spectrum
-a, --aggregation [average|max]
Calculation to aggregate sweep passes
-f, --format [csv] Output format
-v, --verbose
Leave serialport
empty to auto-detect the connect RF Explorer.
start-freq
and end-freq
define the full range of the resulting scan data.
step-resolution
is the size (in MHz) of each smaller scan. For instance, a step-resolution of 2 MHz (the default) results in an effective RBW of 2MHz/112 = 17.9 KHz, which is slightly better than the 25 KHz RBW of many Shure networked microphone receivers. The smaller the step-resolution, the longer the complete scan will take to complete.
In its spectrum analyzer mode, RF Explorer works by repeatedly scanning the configured sweep range. This script will let sweeps run at least iterations
(default 10) times before incrementing the sweep frequencies by the step-resolution. The larger the number of iterations, the longer the scan will take to complete. However, with sufficiently small step-resolutions, there are often 5 or more sweeps complete by the time the script can even check!
With all of the sweep iteration data, the script currently has two aggregation
calculations it can perform on each frequency's amplitude: average
(default) or max
. Average speaks for itself, and max uses the highest value found at each frequency across all iterations -- kind of like a peak hold.
rfexplorerDetailedScan -s 450 -e 650 scan-$(date +%Y%m%d-%H%M%S).csv
This will perform a scan from 450MHz to 650MHz with other defaults: Auto-detected RF Explorer using a baud rate of 500 Kbps, step resolution of 2 MHz (18 KHz RBW), at least 10 sweep iterations per step-resolution, averaging the amplitude at each frequency's sweep. Provided this is a bash-like environment with the date
command available, this will save the results to a CSV file with the current date and time in the name.
This script is made possible by RF Explorer for Python, and much of it is based on the included example scripts.