How do you calculate RF cable length?
To calculate the electrical length of the line you need to multiply the velocity factor of the line (available from the supplier of the line) by the free space length. For the length in feet, this is (983.6 / frequency in MHz) * velocity. For the length in meters, this is (299.8 / frequency in MHz) * velocity.
How do you calculate the power of a coaxial cable?
It is calculated as: (V peak max)2 / (2 * Zo), where Zo is the impedance of the cable. This value must never be exceeded. It is the maximum peak voltage applied between the conductors of the cable in order to prevent the dielectric piercing (breakdown voltage).
How much power can coaxial cable carry?
You need to revise the calculation for air dielectric, in which case you’ll see 256 volts is the maximum voltage, 358 watts is the maximum power into a good load, and 89 watts is the maximum into an unmatched load. Note that at this interface the coax presents 71 ohms impedance.
How do you calculate electrical length?
The relationship between velocity, frequency and wavelength is given by the formula v=fλ v = f λ If the velocity is measured in meters/second and frequency in cycles/second, then λ has units of meters/cycle. We determine if a cable is electrically short, or long, by comparing its length to the wavelength λ.
What are the rules regarding cable length?
A cable length or length of cable is a nautical unit of measure equal to one tenth of a nautical mile or approximately 100 fathoms. Due to anachronisms and varying techniques of measurement, a cable length can be anywhere from 169 to 220 metres, depending on the standard used.
How can you tell a male from a female connector?
A male connector is commonly referred to as a plug and has a solid pin for a center conductor. A female connector is commonly referred to as a jack and has a center conductor with a hole in it to accept the male pin.
How do you calculate the impedance of a coaxial cable?
Another way to measure the characteristic impedance of coax cable is to measure its inductance and capacitance per unit length; the square root of L divided by C will be in ohms (not farads or henrys) and will be equal to the characteristic impedance.
Is there electricity in coaxial cable?
The“signal” on a cable is in fact alternating current electricity, which is of a much, much higher frequency than that of your mains electrical supply. This doesn’t mean that you can’t cut into the cable as the voltage induced onto a coax cable from a TV aerial is very, very low.