MIL-PRF-18546 Resistors, Fixed, Wire-Wound \(Power Type, Chassis Mounted\), General Specification ForThis specification covers the general requirements for power type, wire wound, fixed resistors which utilize the principal of heat dissipation through a metal mounting surface. The resistors have an initial resistance tolerance of ┬▒1 percent and a resistance temperature characteristic range from 30 ppm/Degrees C to 200 ppm/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.