Obtaining Coaxial Cable Coefficients

The SARK-110 allows user specifying custom coaxial cable settings, used for transmission line calculations. Coaxial cable datasheets normally provide attenuattion values at some single frequencies, but not the attenuation constants. Therefore, the attenuation constants have to be obtained by interpolation from the given frequency / attenuation pairs.

SARK Coax calculates automatically the cable attenuation coefficients based on the given frequency / attenuation pairs. In addition, the tool shows a graph of the attenuation or power loss.

The calculated coefficients are compatible with the SARK-110 firmware, SARK Plots, and ZPlots, i.e. in dB/100ft. Notice that the naming of the coefficients and units are different from DL4MW - ATTCALC tool.

Quick usage guide

1. Select the right units (feet or meters): Menu <Units>

2. Create a new file <File><New> or open an existing file <File><Open>

3. If a new file is selected, it will open automatically the Cable Dialog box. Otherwise, select <File><Edit>

4. Enter the cable parameters.

5. Press the button "Calculate" and you will get the calculated coefficients

6. Select OK button. Then the cable attenuation characteristic is display in a graph. The type of graph can be selected in the <Param> combobox.

7. The edit box "SARK-110 Custom cable file entry" contents can be directly copied and pasted to an entry in the "custcab.txt" file, or the values used in SARK Plots or ZPlots


  • Siegfried Riesinger - DH3SR, who brings me the motivation to develop this tool
  • SARK Coax tool was inspired on Ralf Schueler - DL4MW, ATTCALC tool (http://schueler.ws/?page_id=237&lang=en)
  • This tool uses LMFIT-5.1 software: Copyright (c) 2004-2013 Joachim Wuttke, Forschungszentrum Juelich GmbH