MIL-STD-1605 Procedures For Conducting A Shipboard Electromagnetic Interference Emi Survey Surface ShipThis standard provides the procedures for demonstrating compliance with the intra and inter-system electromagnetic compatibility EMC, hull-generated Intermodulation Interference IMI, and electrical bonding requirements of MIL-STD-464 for naval surface ships. In addition, an EMI survey is required for new construction ships and ships receiving overhauls or other major repair work that changes the ships electromagnetic configuration.

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MIL-STD-1605A(SH)

5.1.3 Testing for unintentional electromagnetic emissions. Unintentional electromagnetic emissions from electrical/electronic equipments shall be measured from all electrical/electronic equipment. Electrical/electronic equipment shall be turned on but not placed in transmit mode during Phase I testing. Communications equipment shall be on and not keyed. Radars shall have antennas rotating but not radiating. Other ship electronic systems will be activated to mode which does not cause them to radiate out the antenna.

5.1.3.1 Unintentional emissions test method.

a. Select receiver. Select a sensitive scanning receiver, such as a spectrum analyzer so that the complete test configuration shall have an equivalent noise figure of no more than 30dB at 25 degrees centigrade for bandwidth and frequency(s) defined in table I. The analyzer will interface with the sensor type equipment/systems to measure RF equipment/systems unintentional received emissions. Table I specifies the resolution bandwidth (RBW) and sweep rate to be used over each frequency range to measure the select sensors.

TABLE I. Measurement bandwidth settings.

Frequency Range	6 dB Resolution Bandwidth (RBW)	Minimum Sweep Time (Seconds)
2 MHz - 30 MHz	10 kHz	150Span RBW VBW
30 MHz - 1 GHz	100 kHz
1 GHz - 6 GHz	1 MHz

b. Selected RF sensors. With the unit under test de-energized disconnect the selected sensor antenna from the equipment/system and patch into the sensor antenna with the input lead to the test equipment to measure the reception of unintentional RF emissions on the selected receiver (see figure 2). If a sensor cannot be monitored, the procedures of 5.1.3.1.g shall be used to evaluate the RF ambient in the area of the sensor in question. Connect the test equipment to each sensor antenna prior to any couplers, filters, attenuators and etc, but after any matching units.