MIL-PRF-15305 Coils, Electrical, Fixed And Variable, Radio Frequency General Specification ForThis specification covers the general requirements for radio frequency coils, fixed and variable, for use as simple inductive elements in radio frequency circuits. Procurement of coils of a specific design will require additional data in the form of complementary Service documents, giving detail electrical and mechanical requirements, tolerances, and applicable additions and exceptions to the general requirements and tests specified herein \(see 3.1\).

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MIL-PRF-15305F

6.7.2 Ferrite cores. The degradation limits for Ferrite core coils will not exceed the following limits:

Inductance - - - - - - - - - - - - - - - - - - - - - - -

�10 percent

Q -----------------------------

�20 percent

Self resonant frequency - - - - - - - - - - - - - -

�15 percent

�5 percent +0.001Ω

Direct current resistance - - - - - - - - - - - - -

6.8 Tin whisker growth. The use of alloys with tin content greater than 97 percent, by mass, may exhibit tin

whicker growth problems after manufacture. Tin whiskers may occur anytime from a day to years after manufacture

and can develop under typical operating conditions, on products that use such materials. Conformal coatings applied

over top of a whisker-prone surface will not prevent the formation of tin whiskers. Alloys of 3 percent lead, by mass,

have shown to inhibit the growth of tin whiskers. For additional information on this matter, refer to ASTM-B-545

(Standard Specification for Electrodeposited Coatings of Tin).

6.9 Solder and soldering flux (see 3.3.7) It is recommended that solder and soldering flux to be in accordance with

ANSI/J-STD-004, ANSI/J-STD-005, and ANSI/J-STD-006.

6.10 Environmentally preferable material. Environmentally preferable materials should be used to the maximum

extent possible to meet the requirements of this specification. As of the dating of this document, the U.S.

Environmentally Protection Agency (EPA) is focusing efforts on reducing 31 priority chemicals. The list of chemicals

and additional information is available on their website at https://www.epa.gov/osw/hazard/wastemin/priority.htm.

Included in the EPA list of 31 priority chemicals are cadmium, lead, and mercury. Use of these materials should be

minimized or eliminated unless needed to meet the requirements specified herein (see Section 3).

6.11 Subject term (key word) listing.

Coils, cylindrical, insulated

Cores, ferrite, iron, phenolic

Radio frequency

6.12 Changes from previous issue. Marginal notations are not used in this revision to identify changes with respect

to the previous issue due to the extent of the changes.