ANSI SCTE 48-3 pdf free download

ANSI SCTE 48-3 pdf free download.Test Procedure for Measuring Shielding Effectiveness of Coaxial Cable and Connectors Using the GTEM Cell.
6.3. Calibration and Equipment Preparation Data points – The number of measurement samples taken is at the discretion of the Engineer performing the test, however, as a minimum requirement there will be at least one sample point every5 MHz (i.e.5，10, 15, …. upper frequency limit). When testing frequencies above 1GHz, it may be necessary to use multiple amplifiers to cover the entire range. The following items should be considered when using multiple amplifiers. ● Safety consideration must be taken into account if manually switching between amplifiers, and the amplifier outputs must be off before switching them. ● When using data collecting and control software for a spectrum analyzer, and manually switching amplifiers there should be a pause feature to stop the sweep at the correct frequency to switch amps and then continue sweep once correct amp is in place. ● Be sure to verify that all supporting equipment, i.e. pre amp, attenuators etc. are correctly chosen to cover the entire frequency range in question. RF power level – As this test is designed as a comparison of shielded Vs unshielded cable, an exact field strength is not stated. It is necessary however to have enough energy in the GTEM as is necessary to achieve sufficient dynamic range for the measurements being made. Attenuator characterization – Any attenuators that may be inserted or removed from the measurement during the measurement process shall be characterized and data stored for later use during S.E. calculations.
Preamp characterization – A preamp that may be inserted or removed from the measurement during the measurement process shall be characterized and data stored for later use during S.E. calculations. Analyzer settings: Vector Network Analyzer IF Bandwidth 100Hz maximum Calibration – Through and isolation Spectrum Analyzer Resolution Bandwidth 100Hz maximum 1 second settling duration A system verification shall be performed by removing the GTEM cell, any attenuators, and preamp from the measurement and connecting together all the test leads and adapters used. It is recommended that this system verification be performed without the use of the RF amplifier to ensure no damage to the analyzer occurs. No aluminum foils or ferrites shall be present in the test setup that could affect the test result, test connector / adapter assembly should be soldered to achieve good shielding instead. Note: If the insertion loss measurement is greater than 10 dB, there may be a faulty component in-line and the dynamic range of the S.E. measurement may be reduced.
6.4. Detailed Procedure 6.4.1. Terminator sweep With equipment connected as shown in Figures 2 or 3, place a terminator on the adapter at the floor of the GTEM where signal return to analyzer is. Perform a full sweep of the system and store the data for later use in calculating dynamic range. 6.4.2. Unshielded cable sample Whether or not the coaxial cable connectors are to be included in the S.E. measurement, the verification sample shall consist ofa 1 meter (3.28 ft) length of core (inner conductor and dielectric insulation only) with the appropriate coaxial cable connectors fitted to each end as shown in Figure 4 below. The connectors are typically Type F male. (Helpful Note: A layer of tape may be applied to the end of the core, in order to simulate the foil tape so that the F connector will fit snug. No compression is necessary, so the connectors are reusable.) NOTE: The dielectric and center conductor size and type of the unshielded core should be comparable to the size and type of the dielectric and center conductor of the shielded DUT.ANSI SCTE 48-3 pdf donwload.