The RF transmission loss (attenuation) test (Method 4.8.8) determines the signal attenuation characteristics of flexible and semirigid RF coaxial cables. For swept frequency testing, the cable specimen must be of sufficient length to exhibit no less than 1 dB loss at the low end of the frequency range, with the maximum length limited so that loss at the highest frequency does not exceed the dynamic range of the calibrated measurement system less 10 dB.
For fixed frequency testing, the specimen shall be long enough to exhibit a loss no less than 3 dB and no greater than the dynamic range less 10 dB. Both ends of the specimen shall be terminated by suitable connectors having interfaces in accordance with MIL-STD-348.
A swept frequency RF transmission loss technique is used to determine attenuation within the specified frequency range. The test setup includes a display of RF transmission loss in dB as a function of frequency. The results are compared against the maximum values specified on the applicable specification sheet.