1、 MIL-PRF-1/878G 27 March 2012 SUPERSEDING MIL-PRF-1/878F 7 January 2000 PERFORMANCE SPECIFICATION SHEET ELECTRON TUBE, POWER TYPE 250TH * This specification is approved for use by all Departments and Agencies of the Department of Defense. The requirements for acquiring the electron tube described he
2、rein shall consist of this document and the latest issue of MIL-PRF-1. DESCRIPTION: Triode. See figure 1. Weight: 10 ounces nominal (283.5 grams). Mounting position: Vertical. ABSOLUTE RATINGS: C Telegraphy. Parameter: Unit: F MHz Ef V Eb kV dc Ec V dc Ib mA dc Ic mA dc Pp W Maximum: Minimum: 40 - 5
3、.25 4.75 3.0 - -210 - 330 - 75.0 - 250 - Test conditions: - 5.0 V ac 2.5 Adjust 100 - - See footnotes at end of table I. _ GENERAL: Qualification: Not required. Holding period: (MIL-STD-1311): 1/ This specification sheet uses accept on zero defect sampling in accordance with MIL-PRF-1, table III. _
4、* Tube type 250TL has been deleted from this tube specification sheet. Use EIA Type 250TL. AMSC N/A FSC 5960 INCH-POUND Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/878G 2 TABLE I. Testing and inspection. Inspection Method Conditions Sym
5、bol Limits Unit MIL-STD-1311 Min Max Conformance inspection, part 1 Filament current 1301 If 9.7 11.2 A ac Total grid current 1266 Ic - -15 A dc Electrode voltage (grid) 1261 Ec -27.0 -39.0 V dc Primary grid emission 1266 Ef = 5.5 V ac; Ic = 175 mA dc; t = 15 Isg - -500 A dc Peak emission 1231 eb =
6、ec = 2,500 v is 5.0 - a Conformance inspection, part 2 Amplification factor 1316 Mu 31.0 41.0 - Power oscillation 1236 Eb = 3,000 V dc; Ib = 300 mA dc; F = 8 MHz Po 540 - W Direct-interelectrode capacitance 1331 Cgp Cin Cout 2.2 3.7 - 3.0 5.1 0.6 pF pF pF See footnotes at end of table. Provided by I
7、HSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/878G 3 TABLE I. Testing and inspection - Continued. Inspection Method Conditions Symbol Limits Unit MIL-STD-1311 Min Max Conformance inspection, part 3 Life test - Group C; power oscillation; t = 500 hours
8、 - - - - Life-test end points: Peak emission Primary grid emission - 1231 1266 is Isg 3.5 - - -500 a A dc Low-frequency vibration 1031 No voltages 2/ - - - - Bump 1036 Angle = 20 2/ - - - - Low-frequency vibration and bump end points: Total grid current Electrode voltage (grid) - 1266 1261 Ic Ec - -
9、27.0 -15 -39.0 A dc V dc 1/ In addition to the 24-hour holding period, 10 percent of the tubes in any production lot shall be held for a period of 72 hours. If more than 2 percent of the tubes fail to meet the total grid current test, the tubes represented by this sample shall be subject to recall a
10、nd all tubes shall be held for a period of 72 hours. 2/ This test shall be performed yearly, with sampling as follows: n1 = 4 c1 = 0 where c2 represents the total failures for the first and second samples combined. n2 = 4 c2 = 0; In case of failure, the test shall become a conformance inspection, pa
11、rt 2 test for three successive successful submissions, at which time the test may revert to the yearly basis. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/878G 4 NOTES: 1. This test shall be performed yearly, with sampling as follows: n1
12、 = 4 c1 = 0 where c2 represents the total failures for the first and second samples combined. n2 = 4 c2 = 0; In case of failure, the test shall become a conformance inspection, part 2 test for three successive successful submissions, at which time the test may revert to the yearly basis. 2. On finis
13、hed tube, add .060 inch (1.52 mm) maximum for solder. FIGURE 1. Outline drawing of electron tube type 250TH. Dimensions Ltr Inches Millimeters Notes Min Max Min Max Conformance inspection, part 2 A 9.625 10.125 244.48 257.18 B - 3.813 - 96.85 D 5.688 6.188 144.48 157.18 F 1.563 1.938 39.70 49.23 J .
14、312 - 7.92 - Conformance inspection (periodic check) part 3 1 C 9.375 9.875 238.13 250.83 E - 1.867 - 47.42 H - .082 - 2.08 K .065 .071 1.65 1.80 P .250 .320 6.35 8.13 2 Q - .109 - 2.77 V - 2.500 - 63.50 X .328 - 8.33 - Z .350 .365 8.89 9.27 AA .185 .189 4.70 4.80 AB 80 100 Reference dimensions G 1.
15、225 31.12 2 L 1.938 49.23 M 2.719 69.06 2 N .031 0.79 R .688 17.48 S .344 8.74 T .344 8.74 U .688 17.48 W .563 14.30 Y .500 12.70 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/878G 5 Referenced documents. In addition to MIL-PRF-1, this sp
16、ecification sheet references MIL-STD-1311. The margins of this specification are marked with vertical lines to indicate where changes from the previous issue were made. This was done as a convenience only and the Government assumes no liability whatsoever for any inaccuracies in these notations. Bid
17、ders and contractors are cautioned to evaluate the requirements of this document based on the entire content irrespective of the marginal notations and relationship to the last previous issue. Custodians: Preparing activity: Army - CR DLA - CC Navy - EC Air Force - 85 (Project 5960-2012-012) DLA - C
18、C Review activities: Army - AR Navy - AS, CG, MC, OS, SH Air Force - 19, 99 NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST Online database at https:/assist.daps.dla.mil/. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
