Enter Length of Cable in Feet?
This is simply the length of the cable measured in feet
Enter Power into Cable in Watts?
This is the actual measured power going into the coaxial cable. This value is usually obtained by inserting an inline wattmeter as close to the transmitter output connector as possible. Sometimes it might be necessary to measure the transmitter power with only the inline wattmeter and a dummy load first to establish a good reference.
Enter Gain of Antenna in dBd?
This is the gain of the antenna system in dB referenced to a dipole (dbd).