I am looking for lightning surge data for suspended coaxial lines, hardline and braid. To date, I have only located one study that specifically obtained data on suspended coaxial lines. I must be looking in the wrong places, since there seem to be many studies of the nature and effects of lightning in the last century. Most of the data I have found is for power lines and telecom interconnect or interfacilities wiring. I am seeing the tendency for cable distribution system operators to suggest that the same surge test criterion that are being used for the power mains be applied to coaxial RF ports and believe that these are unrealistically severe criterion to apply to the components connected to the center conductor of a coaxial line. While the sheath current on a coaxial line may be quite large in magnitude during a near strike, the current induced onto the center conductor of the coaxial line and the energy available from the center conductor are much lower than what may be induced into the unshielded power mains leads.
Most test standards do not seem to directly address rf coaxial ports. Bellcore does with GR-1089 CORE using a 10/250us combination wave with +/- 2000V/1000A for testing RF ports. The number of joules that needs to be dissipated for this test appears to be much higher than what the one study I have seen indicates is available on the coax center conductor during a near lightning strike. I know of no one testing cable tv tuners or modems to the Bellcore spec.
Any recommendation of where to find other references with data on lightning surge measurements on coaxial lines or surge testing of RF coaxial ports would certainly be appreciated.
TIA, Pete Schreiner
