Parameters tab - voxo22/hackrf-spectrum-analyzer GitHub Wiki

RESET PARAMS button

The RESET PARAMS button restores the main spectrum analyzer to typical defaults. Useful if you have changed many settings and want to start over.

  • Frequency range: 920 - 960 MHz
  • RBW: 50 kHz
  • Combined gain: 52 dB
  • Frequency shift: 0 MHz
  • Peak trace: enabled
  • Max hold trace: enabled
  • Waterfall: enabled
  • Waterfall palette: start -110 dB, length 65 dB
  • Waterfall speed: 4
  • Video area: SPECTR
  • Video format: GIF
  • Video resolution: 540p
  • Video frame rate: 15 fps
  • STATS interval: SEC

Note: This button resets last used values from previous session.

Spline

Spline checkbox turns on visual improvement of the style of thin trace lines, but consumes more CPU power.

Lines Thickness

You can choose different line thicknesses for the traces. Thicker lines can be useful in MP4 format VIDEO recordings.

Peak Fallout Time

In the case of analyzing short amplitude pulses, various hold methods can be applied to the PEAK trace. While the increase in amplitude is recorded immediately (similar to REALTIME), the PEAK trace holds its position on the chart for a certain time.

PEAK fallout time determines how long in seconds the peak amplitude will "fall" to its minimum, until another pulse at the same frequency arrives. In practice, the PEAK trace is constantly "falling" and this parameter determines how fast.

Note: This parameter is only displayed if the PEAK trace is displayed.

Peak Fall Threshold

PEAK fall threshold time determines how smoothly the peak amplitude will "fall" to its minimum until another pulse at the same frequency arrives. In practice, the PEAK trace is constantly "falling" and this parameter determines how many "fall" steps are to be skipped.

Note: This parameter is only displayed if the PEAK trace is displayed.

Peak Hold Time

Peak hold time is the time during which the trace will hold its maximum PEAK value (it will not gradually "fall"). If you set this parameter to a value greater than 0, the PEAK will be held for a given number of seconds. This is useful, for example, in STATS logging while setting a second or minute interval.

If you want to log STATS using second period, set Peak hold time to 1, so the the MAX value will be held for a second. If you want to log STATS using minute period, set Peak hold time to 60, so the MAX value will be held for a whole minute. However, during this time the PEAK trace can raise, but it will not fall. It always be held for a given number of seconds.

Note: This parameter is only displayed if the PEAK trace is displayed.

Marker count

You can choose from 1 to 5 PEAK trace and MAX HOLD markers.

Note: This parameter is only displayed if the MARKER PEAK or MARKER MAX HOLD checkbox on the SWEEP tab is checked.

Persistent Decay Rate

Persistent chart is a specific type of spectral analysis that displays the frequency of occurrence of an amplitude at a given frequency in color. In order to capture rapid amplitude changes in some cases, a certain display hold time is applied.

The decay rate parameter sets the time in seconds at which the colored points disappear from the chart.

Note: This parameter is only displayed if PERSISTENT chart is displayed.

Average Iterations

This parameter determines the number of averaging iterations in the AVERAGE trace. Amplitude value is preserved by averaging and short pulses are filtered. The iterations are calculated from the REALTIME trace, you can choose averaging from 20, 50 or 80 iterations. The higher the number of iterations, the smoother the trace, but short pulses will be more vanished.

Note: This parameter is only displayed if the AVERAGE trace is displayed.

Average Offset

Average offset slider moves AVERAGE trace along the Y-axis. In some cases it can undesirably hide below the -100 dBm limit, so you can correct the situation by moving this slider.

Note: This slider is only displayed if the AVERAGE trace is displayed.

Frequency Allocation Bands

The frequency allocation bands drop-down list allows you to select from various user-defined frequency band allocations. The drop-down list entries are loaded as present CSV files in the "freq" folder. They are sorted alphabetically.

Frequency band allocations can be useful for navigation in the spectrum. You can create your own by simply modifying existing file. The CSV file has the following structure (e.g.):

"Country";"Frequency Range";"Applications";"Color"
"SK";"5900 - 6200 kHz";"49m SW radio";"#0000FF"
"SK";"21000 - 21450 kHz";"15m HAM";"#DEB887"
"SK";"87.500 - 108.000 MHz";"FM radio";"#9400D3"
"SK";"174.000 - 240.000 MHz";"DAB+";"#FF69B4"
"SK";"431.000 - 435.000 MHz";"ISM 433";"#DC143C"
"SK";"703.000 - 713.000 MHz";"LTE700/O2/uplink";"#00658c"
"SK";"713.000 - 723.000 MHz";"LTE700/Telekom/uplink";"#e70073"
"SK";"723.000 - 733.000 MHz";"LTE700/Orange/uplink";"#ff6500"
"SK";"758.000 - 768.000 MHz";"LTE700/O2/downlink";"#00658c"
"SK";"768.000 - 778.000 MHz";"LTE700/Telekom/downlink";"#e70073"
"SK";"778.000 - 788.000 MHz";"LTE700/Orange/downlink";"#ff6500"

Frequency range can be in kHz or MHz. The "/" character creates new line. The last parameter sets the color shade of the allocation bar in HEX code.