Interference tests on HF modems

Proposes a series of laboratory tests, based on generic types of interference, which could be used to provide reference data for the comparison of alternative modem designs. The rationale for the selected set of tests is described. These measurements were originally developed to permit the qualitative evaluation of medium speed HF data modems, operating at information rates of 1200 and 2400 bits/second. To illustrate the test procedures, the results obtained from measurements on two types of medium-speed modems are presented. These results show that the tests provide a useful indication of the modems´ sensitivity to interference