The second calculator is given the capacitance in pF per meter and length, and it will calculate the impedance at a frequency.
http://www.sengpielaudio.com/calculator-cable.htm
Electronics & Stuff, a lot about LEDs
The second calculator is given the capacitance in pF per meter and length, and it will calculate the impedance at a frequency.
http://www.sengpielaudio.com/calculator-cable.htm