1、 AMSC N/A FSC 5910 MIL-PRF-14409H 7 April 2008 SUPERSEDING MIL-PRF-14409G 4 December 2006 PERFORMANCE SPECIFICATION CAPACITORS, VARIABLE (PISTON TYPE, TUBULAR TRIMMER) GENERAL SPECIFICATION FOR This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SC
2、OPE 1.1 Scope. This specification covers the general requirements for tubular-trimmer, piston-type, variable capacitors intended primarily for use in high-frequency trimming applications where relatively few adjustments are required during the effective life of the equipment. 1.2 Classification. * 1
3、.2.1 Part or Identifying Number (PIN). Capacitors specified herein are identified by a PIN. The term “Part or Identifying Number (PIN)” is equivalent to the term “type designation” that was previously used in this specification. The PIN is in the following form and as specified (see 3.1 and 6.1): 1.
4、2.1.1 Style. The style is identified by the two-letter symbol “PC“ followed by a two-digit number; the letters identify tubular-trimmer, piston-type, variable capacitors, and the number identifies the shape or differentiating electrical characteristics of the capacitor. 1.2.1.2 Characteristic. The c
5、haracteristic is identified by a single letter in accordance with table I. 1.2.1.3 Capacitance. The nominal maximum rated capacitance value expressed in picofarads (pF) is identified by a three-digit number; the first two digits represent significant figures and the last digit specifies the number o
6、f zeros to follow. When fractional values are required, the letter “R“ should be used to indicate the decimal point. For example: 8R5 indicates 8.5 pF. INCH-POUND PC51 H 380 Style (1.2.1.1) Characteristic (1.2.1.2) Capacitance (1.2.1.3) Comments, suggestions, or questions on this document should be
7、addressed to: Defense Supply Center, Columbus, DSCC-VAT, Post Office Box 3990, Columbus, OH 43218-3990 or e-mailed to capacitorfilterdla.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at http:/assist.daps.dl
8、a.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-14409H 2 TABLE I. Characteristic. Symbol Operating temperature range (C) Temperature coefficient referred to an ambient temperature of 25C (Parts/million/C) Capacitance drift G -55 to +12
9、5 150 .5 percent maximum rated value H -55 to +125 100 .2 percent of maximum rated value or .04 pF (whichever is greater) J -55 to +125 50 .15 percent of maximum rated value or .02 pF (whichever is greater) K -55 to +125 0 75 .18 percent of maximum rated value or .03 pF (whichever is greater) Q -55
10、to +150 +50, -0 .1 percent of maximum rated value or .01 pF (whichever is greater) T -65 to +125 20 .1 percent of maximum rated value or .01 pF (whichever is greater) L -55 to +125 50 50 .1 percent of maximum rated value or .01 pF (whichever is greater) 2. APPLICABLE DOCUMENTS 2.1 General. The docum
11、ents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this lis
12、t, document users are cautioned that they must meet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks f
13、orm a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. FEDERAL STANDARDS FED-STD-H28 - Screw-Thread Standards for Federal Services. DEPARTMENT OF DEFENSE STANDARDS MIL-STD-202 - Test Metho
14、d Standard Electronic and Electrical Component Parts. MIL-STD-1285 - Marking of Electrical and Electronic Parts. (Copies of these documents are available online at http:/assist.daps.dla.mil/quicksearch/ or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, P
15、A 19111-5094.) 2.3 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtaine
16、d. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-14409H 3 3. REQUIREMENTS 3.1 Specification sheets. The individual item requirements shall be as specified herein and in accordance with the applicable specification sheets. In the event of an
17、y conflict between requirements of this specification and the specification sheets, the latter shall govern (see 6.1). 3.2 Qualification. Capacitors furnished under this specification shall be products which are qualified for listing on the applicable qualified products list at the time set for open
18、ing of bids (see 4.3 and 6.2). 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 capacitors to meet the performance requirements of this specification. Acceptance or approval of any constituent
19、material shall not be construed as a guaranty of the acceptance of the finished product. 3.3.1 Pure tin prohibition. The use of pure tin, as an underplate or final finish, is prohibited both internally and externally. Tin content of components and solder shall not exceed 97 percent, by mass. Tin sha
20、ll be alloyed with a minimum of 3 percent lead, by mass (see 6.5). 3.4 Design and construction. Capacitors shall be of the design, construction, and physical dimensions specified (see 3.1). 3.4.1 Threaded parts. All threaded parts shall be in accordance with FED-STD-H28, and shall be as specified (s
21、ee 3.1). 3.4.2 Locking of screw-thread assemblies. All screw-thread mounting assemblies shall be rendered resistant to loosening under vibration. If needed, lockwashers and nuts compatible with assembly finish, shall be provided. 3.4.3 Terminals. All terminals shall be coated, electro-tin plated, or
22、 hot tin dipped with a solder having a minimum tin content of 40 percent (pure tin is prohibited (see 3.3.1) or shall be gold plated. 3.4.4 Connections. Electrical connections shall not depend upon wires, lugs, terminals, and the like clamped between a metallic member and an insulating material. Suc
23、h connections shall be soldered. 3.5 Thermal shock. When capacitors are tested as specified in 4.5.1, there shall be no evidence of fracture or loosening of mechanical connections. In addition, corrosion of exposed metallic surfaces shall not exceed 10 percent. (Discoloration and tarnishing alone sh
24、all not be cause for rejection.) 3.6 Capacitance. When measured as specified in 4.5.3, the minimum capacitance shall be not more and the maximum not less than the value specified (see 3.1). The capacitance range may be broader than that specified, provided it encompasses the specified range. 3.7 Cha
25、nge of capacitance. When capacitors are tested as specified in 4.5.4, the rate of change of capacitance as a function of the change of adjustment shall not change sign over the entire range of adjustment. 3.8 Insulation resistance. When capacitors are tested as specified in 4.5.5, the insulation res
26、istance shall be not less than the value specified (see 3.1). 3.9 Dielectric withstanding voltage. When capacitors are tested as specified in 4.5.6, there shall be no evidence of damage, arcing, or breakdown. 3.10 Quality factor (Q). When capacitors are tested as specified in 4.5.7, the Q shall exce
27、ed the value specified (see 3.1). 3.11 Torque. 3.11.1 Driving torque. When measured as specified in 4.5.8.1, the torque required to start and maintain rotation of the rotor shall be greater than or equal to 1 and less than or equal to 10 inch-ounces at all temperatures, unless otherwise specified (s
28、ee 3.1). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-14409H 4 3.11.2 Torque bushing strength (panel mount units only). When capacitors are tested as specified in 4.5.8.2, there shall be no evidence of bushing breakage, thread stripping, o
29、r other visible mechanical damage. 3.12 Temperature coefficient and capacitance drift. Unless otherwise specified, when capacitors are tested as specified in 4.5.9, the temperature coefficient and capacitance drift shall be within the limits specified in table I (see 3.1). 3.13 Immersion (sealed uni
30、ts only) (see 3.1). When capacitors are tested as specified in 4.5.10, the following requirements shall be met: Capacitance (maximum) Shall change not more than .5 pF or 5 percent, whichever is greater. Insulation resistance at room ambient temperature Shall be not less than 100,000 megohms. Dielect
31、ric withstanding voltage As specified in 3.9. 3.14 Salt atmosphere (corrosion). 3.14.1 Salt atmosphere (corrosion) (sealed units only) (see 3.1). When capacitors are tested as specified in 4.5.11.1, the following requirements shall be met: Insulation resistance at room ambient temperature Shall not
32、be less than 100,000 megohms. Dielectric withstanding voltage As specified in 3.9. Driving torque at room ambient temperature As specified in 3.11.1. Corrosion of exposed metallic surfaces shall not exceed 10 percent. Discoloration and tarnishing alone shall not be cause for rejection. 3.14.2 Salt a
33、tmosphere (corrosion) (unsealed units only). When capacitors are tested as specified in 4.5.11.2, corrosion of exposed metallic surfaces shall not exceed 10 percent. Discoloration and tarnishing alone shall not be cause for rejection. 3.15 Low-temperature storage. When capacitors are tested as speci
34、fied in 4.5.12, there shall be no visible mechanical damage to the capacitors. 3.16 Shock (specified pulse). When capacitors are tested as specified in 4.5.13, there shall be no intermittent contacts of 0.5 milliseconds (ms) or greater duration, or momentary arcing, open-circuiting or short-circuiti
35、ng, or any evidence of fractures, loosening of parts, or other visible mechanical damage. 3.17 Vibration, high frequency. When capacitors are tested as specified in 4.5.14, there shall be no intermittent contacts of 0.5 ms or greater duration, or momentary arcing, open-circuiting or short-circuiting
36、, or any evidence of fracture, loosening of parts, or other mechanical damage visible under 10 power magnification. The capacitance change shall be not more than 1 percent or 0.05 pF, whichever is greater, from the initial value obtained when measured as specified in 4.5.14. 3.18 Barometric pressure
37、 (reduced, qualification only). Unless otherwise specified (see 3.1), when capacitors are tested as specified in 4.5.15, they shall withstand a potential of 50 percent of the dc rated voltage or 500 volts, whichever is less without damage, arcing, or breakdown. 3.19 Moisture resistance. When capacit
38、ors are tested as specified in 4.5.16, the following requirements shall be met: Insulation resistance at room ambient temperature Shall not be less than 100,000 megohms. Dielectric withstanding voltage As specified in 3.9. Driving torque at room ambient temperature As specified in 3.11.1. Provided b
39、y IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-14409H 5 Corrosion of exposed metallic surfaces shall not exceed 10 percent. Discoloration and tarnishing alone shall not be cause for rejection. 3.20 Terminal strength. When capacitors are tested as spec
40、ified in 4.5.17, there shall be no loosening or rupturing of the terminals or other damage to the terminals or capacitor body. A slight separation (not exceeding .063 inch (1.60 mm) of wire leads from the cylindrical body at the point the lead leaves the cylinder is acceptable. 3.21 Resistance to so
41、ldering heat (printed circuit mount types only, see 3.1). When capacitors are tested as specified in 4.5.18, they shall meet the following requirements after resistance to soldering heat: Capacitance Shall be as specified in 3.6. Dielectric withstanding voltage Shall be as specified in 3.9. Quality
42、factor Shall be as specified in 3.10. Visual examination There shall be no evidence of mechanical damage. 3.22 Seal (sealed units only) (see 3.1). When capacitors are tested as specified in 4.5.19, there shall be no evidence of dye penetration and they shall meet the following requirements: Capacita
43、nce (maximum) Shall change not more than .5 pF or 5 percent, whichever is greater. Insulation resistance at room ambient temperature Shall be not less than 100,000 megohms. Dielectric withstanding voltage As specified in 3.9. 3.23 Rotational life. When capacitors are tested as specified in 4.5.20, t
44、he following requirements shall be met: Dielectric withstanding voltage As specified in 3.9. Contact resistance Shall not exceed 0.01 ohm after test. Capacitance change versus Rotation Capacitance change versus rotation of the rotor shall not deviate from a straight line by more than 10 percent and
45、shall show no reversals in direction unless otherwise specified (see 3.1). Driving torque at room ambient temperature As specified in 3.11.1. 3.24 Solderability (all solderable terminals). When capacitors are tested as specified in 4.5.21, the dipped surface of the leads shall be at least 95 percent
46、 covered with a new, smooth, solder coating. The remaining 5 percent of the lead surface shall show only small pinholes or rough spots; these shall not be concentrated in one area. Bare base metal and areas where the solder dip failed to cover the original coating are indications of poor solderabili
47、ty, and shall be cause for failure. In case of dispute, the percent of coverage with pinholes or rough spots shall be determined by actual measurement of these areas, as compared to the total area. * 3.25 Marking. Marking of capacitors shall conform to method I of MIL-STD-1285 and shall include the
48、PIN, date and lot codes, and manufacturers symbol or trademark. There shall be no space between symbols which comprise the PIN. If space limitation requires it, the PIN may appear on two lines. In this event, the PIN shall be divided between the style and the characteristic symbols and shall appear
49、on two lines as shown in the following example: PC51 H380 Marking shall remain legible after all tests. 3.25.1 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environmentally preferable materials should be used to the maximum extent possible provided that the material meets or exceeds the operational and maintenance requirements, and promotes economically advantageous life cycle costs. 3.26 Workmanship. Capacitors shal
