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

4.6.2 Thermal shock and voltage conditioning (see 3.7). Filters shall be subjected to the tests of 4.6.2.1 and

4.6.2.2.

4.6.2.1 Thermal shock. Filters shall be tested as specified in method 107 of MIL-STD-202. The following details

and exceptions shall apply:

a. Test condition A, except that in step 3, sample units shall be tested at +125�C.

b. Mounting (class S filters only). Filters shall be mounted in a through-hole and torqued in place on a rigid

metal plate to the specified value (see 3.1). (Note: Not applicable to solder-in types).

c. Measurements during the test (class S filters only). At completion of or during the final cycle and before the

filter is removed from the plate, measure and record insulation resistance at +125�C.

4.6.2.2 Voltage conditioning.

4.6.2.2.1 Class B filters. Filters shall be tested as specified in method 108 of MIL-STD-202. The following details

and exceptions shall apply:

a. Test temperature and tolerance: +125�C � 3�C.

b. Operating conditions:

DC rated filter: 2 x rated voltage for 164 � 4 hours.

(1)

(2)

For filters with ac and dc ratings, or ac ratings only: Apply 1.2 x rated ac voltage at maximum rated

frequency for 164 � 4 hours.

c. Mounting: Filters shall be mounted in such a way that the specified voltage may be applied between the

terminals and case.

d. Measurements after test: Insulation resistance shall be measured as specified in 4.6.13.2.

4.6.2.2.2 Class S filters. Filters shall be tested as specified in method 108 of MIL-STD-202. The following details

and exceptions shall apply:

a. Test temperature and tolerance: +125�C � 3�C.

b. Operating conditions.

(1) DC rated filter: 2 x rated voltage.

(2) Filters with ac and dc ratings, or ac ratings only: 1.2 x rated ac voltage at maximum rated frequency.

(3) Polarity of voltage: The polarity of the voltage shall be positive on the case during the first 24 to 72

hours and then reversed to negative on the case for the remaining portion of the test.

c. Mounting: Filters shall be mounted in such a way that the specified voltage may be applied between the

terminals and case. The method of electrically contacting the case and one terminal of the filter must be

adequate to ensure that all the filters will be properly conditioned.

d. Test circuit: The test circuit shall be equivalent to that shown on figure 1. The maximum series resistance

with each filter shall be 5.00 ohms. The fuse shall have a maximum rating of 0.25 ampere. The power

supply shall be capable of supplying five times the maximum current rating of the fuse.