electromagnetic interference. Filters furnished to the requirements of this specification contain shunting ceramic discoidal capacitors and series inductors \(FSC 5915\). Capacitors furnished to the requirements of this specification contain shunting ceramic discoidal capacitors \(FSC 5910\). For the purposes of this specification, feed-through capacitor types \(C circuit configuration\) are referred to herein as a filter. Passband power may be alternating current \(ac\) or direct current \(dc\) and the filters used primarily in the reduction of broadband radio frequency interference. This specification provides for two levels of product assurance requirements. Filters covered by this specification are capable of operation over the temperature range of -55 degrees C to +125 degrees C.

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MIL-PRF-28861D

4.6.13 Insulation resistance (terminal to ground) (see 3.18).

4.6.13.1 Insulation resistance (+25�C). Filters shall be tested in accordance with method 302 of MIL-STD-202.

The following details and exceptions shall apply:

a. Ambient temperature: +25�C � 3�C.

b. Test potential: Rated dc voltage, applied for 2 minutes maximum. Charging current: 50 mA maximum.

c. Relative humidity: 20 to 50 percent.

d. Points of measurement: Between either terminal and ground (case).

e. At the manufacturer's option, measurements at +25�C can be made of the dc leakage current at the

specified test voltage. The equivalent insulation resistance can then be calculated.

4.6.13.2 Insulation resistance (+125�C). Filters shall be tested in accordance with method 302 of MIL-STD-202.

The following details and exceptions shall apply:

a. Test temperature: +125�C � 3�C.

b. Filters shall be stabilized at +125�C � 3�C.

c. Insulation resistance distribution (class S high frequency bolt style and solder-in style filters only):

Following the voltage conditioning test specified in the group A inspection and measurement of insulation

resistance at +125�C as specified in 4.6.13.2a and 4.6.13.2b, a mean and standard deviation shall be

calculated for the lot based on the first 50 pieces that meet the minimum insulation resistance requirement.

All remaining parts in the lot that have an insulation resistance value less than 3 sigma below the mean

shall not be delivered. These units may, at the option of the manufacturer, be used for group B tests.

(Note: Only parts failing the minimum insulation resistance requirement shall be counted as part of the

percent defective allowed.)

d. Test potential: Rated dc voltage, applied for two minutes maximum. Charging current: 50 mA maximum.

e. At the manufacturer's option, measurements at +125�C can be made of the dc leakage current at the

specified test voltage. The equivalent insulation resistance can then be calculated.

4.6.14 Current overload (see 3.19). Filters shall be suspended by their conductors in free air. A current equal to

140 percent of rated current at maximum rated frequency shall then be applied for 15 minutes minimum. After the

filter has returned to room temperature, the insulation resistance (at +25�C) and voltage drop shall be measured as

specified in 4.6.13.1 and 4.6.6, respectively. Filters shall be visually inspected for evidence of physical damage.

4.6.15 Resistance to solvents (see 3.20). Filters shall be tested in accordance with method 215 of MIL-STD-202.

The following details shall apply:

a. The marked portion of the filter body shall be brushed.

b. Filters shall be visually inspected for evidence of mechanical damage and legibility of marking.

4.6.16 Vibration (high frequency) (see 3.21). Filters shall be tested in accordance with method 204 of MIL-STD-

202. The following details and exceptions shall apply:

a. Mounting of specimens: Filters shall be rigidly mounted by the body.

b. Electrical load: DC rated voltage and current shall be applied continuously during vibration.

c. Test condition E (50 g's) except the frequency range shall be 20 to 3,000 Hz.