Degrees C depending upon the resistance value. They are not capable for application when the alternating current \(ac\) characteristics are of critical importance; however, provisions have been made to minimize the inductance.

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MIL-PRF-18546G

3. REQUIREMENTS

3.1 Specification sheets. The individual item requirements shall be as specified herein and in

accordance with the applicable specification sheet. In the event of any conflict between the requirements

of this specification and the specification sheet, the latter shall govern (see 6.2).

3.2 Qualification. Resistors furnished under this specification shall be products which are authorized

by the qualifying activity for listing on the applicable Qualified Product List (QPL) at the time of award of

contact (see 4.4 and 6.3).

3.3 Material. The material shall be as specified herein. However, when a definite material is not

specified, a material shall be used which will enable the resistors to meet the performance requirements

of this specification. Acceptance or approval of any constituent material shall not be construed as a

guaranty of the acceptance of the finished product.

3.4 Interface and physical dimension. Resistors shall meet the interface and physical dimensions

specified (see 3.1). Resistors shall be wound with a resistance wire (round or flat-wound ribbon), except

as required for noninductive performance of applicable styles (see 3.1). When applicable, in order to

minimize inductance, resistors shall be wound by one of the following methods:

a. Ayrton-Perry.

b. Bifilar.

c. Or equivalent method.

3.4.1 Protective coating or enclosure. The resistance element and caps shall be protected by a

coating or an enclosure which shall completely cover the exterior of the resistance element and caps.

The enclosure shall be free from holes, fissures, chips, and other faults. Small cracks and molding flaws

which do not adversely affect the unit's ability to meet all environmental requirements of this specification

will not be considered a cause for rejection. The exposed end of the enclosure shall prevent the

entrapment of moisture.

3.4.2 Housing. The housing shall be protected against corrosion. All fasteners shall be plated.

Unplated copper bearing metals shall not be used in contact with aluminum.

3.4.3 Terminals. When applicable, terminals shall be treated to facilitate soldering. When a coating

containing tin is used, the tin content shall range between 40 percent and 70 percent. The terminals shall

be firmly secured and shall not be solely dependent on the protective coating or enclosure for mechanical

anchorage.

3.4.3.1 Solder dip (retinning) leads. Only the manufacturer or his authorized MIL-PRF-39009 category

B or C distributor may solder dip/retin the leads of product supplied to this specification provided the

solder dip/retin process (see appendix A) has been approved by the qualifying activity.

3.4.4 Threaded parts. All threaded parts shall be in accordance with FED-STD-H28.

3.4.5 Weight. Resistors shall not exceed the maximum weight specified (see 3.1).