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What is the velocity factor of rg6 coax?
DX Engineering RG-6/U cable impedance is 75 ohms with an 83 percent velocity factor and have a minimum bend radius of 2.50 in.
How much resistance should a coaxial cable have?
Most RF Coaxial Cables have an impedance of 50 ohms or 75 ohms. These are considered to be standardized impedance values with cables readily available. In some cases, users require a custom impedance value. This can be achieved by regulating the inner and outer diameter of the coaxial cable, along with the dielectric.
How are ferrite beads used in RF decoupling?
Ferrite beads are used for RF decoupling and parasitic suppression. When placed over a wire, cable or coaxial cable they suppresses common mode current flowing on the wire or wire bundle or the outside of the coax shield but does not affect the signal inside the coax cable or wire (differential current).
Does the position of the ferrite bead really matter?
Often I will see a ferrite bead a couple of inches from one end of a cable. Does the position of a ferrite bead really matter? My answer hopefully applies to beads but also ferrite clamps on cables. If it’s preventing susceptibility problems due to interference coming down a cable then its position is not that critical.
What kind of cable to use for ferrite beads?
Here is a simple idea that is cost effective and simple to make using FB102-31 ferrite beads with RG-58 (1/4″) size cable. Take a FB102-31 bead and insert 4 turns of RG58 spreading them out 360 degrees to minimize the capacity effects. 4 turns give 16X the choking impedance of a single bead.
What does a bead do to a wire?
Beads provide suppression by impeding (developing a voltage across the bead) and absorbing (converting to heat) magnetic fields (resulting from to currents on the wire). Beads provide the most suppression at VHF and UHF current maxima (as-in standing waves).