1、 MIL-PRF-1/887E 27 March 2012 SUPERSEDING MIL-PRF-1/887D 7 January 2000 PERFORMANCE SPECIFICATION SHEET ELECTRON TUBE, POWER TYPE 8438 * This specification is approved for use by all Departments and Agencies of the Department of Defense. The requirements for acquiring the electron tube described her
2、ein shall consist of this document and the latest issue of MIL-PRF-1. DESCRIPTION: Tetrode. See figure 1. Mounting position: Vertical, base down or up. Weight: 9 ounces (255.15 grams) nominal. ABSOLUTE RATINGS: F1 = 110 MHz. Parameter: Unit: Ef V ac Eb V dc Ec1 V dc Ec2 V dc Ib mA dc Pp W Pg1 W Pg2
3、W Cooling 1/ Maximum: C Telep: C Teleg: AB Audio: 5.0 5% 5.0 5% 5.0 5% 3,200 4,000 4,000 -500 -500 -500 600 600 800 275 350 350 270 400 400 10 10 10 35 35 35 - - - Test conditions: 5.0 2,500 Adj 500 160 - - - 2/ See footnotes at end of table I. _ GENERAL: Qualification: Not required. This specificat
4、ion sheet uses accept on zero defect sampling in accordance with MIL-PRF-1, table III. _ * Formerly JAN 8438/4-400A. AMSC N/A FSC 5960 INCH-POUND Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/887E 2 TABLE I. Testing and inspection. Inspec
5、tion Method Conditions Symbol Limits Unit MIL-STD-1311 Min Max Conformance inspection, part 1 Filament current 1301 If 13.5 14.7 A ac Total grid current 1266 4/ Ic1 - -10 A dc Primary-grid emission (control) 1266 Ef = 5.5 V ac; Ic1 = 165 mA dc; t = 15; anode and screen grid floating Isg1 - -100 A dc
6、 Primary-grid emission (screen) 1266 Ef = 5.5 V ac; Ic2 = 135 mA dc; Ec1 = 0; t = 15; anode floating Isg2 - -200 A dc Electrode voltage (grid) 1261 Ec1 -55 -80 V dc Peak emission 1231 eb = ec1 = ec2 = 2,500 v is 7.0 - a Conformance inspection, part 2 Amplification factor 1316 g1 to g2; Ic2 = 70 mA d
7、c; Eb = 0 Mu 4.5 6.0 - Power oscillation 1236 Class C amplifier; grid driven; Eb = 3 kV dc; Eg1/Ib = 350 mA dc; F = 110 MHz (min) Po 500 - W (useful) Direct-interelectrode capacitance 1331 Cgp Cin Cout - 10.70 4.20 0.17 14.50 5.60 pF pF pF Conformance inspection, part 3 Life test - Group C; power ou
8、tput; t = 500 hours - - - - Life-test end points: - Peak emission 1231 is 5.6 - a Primary-grid emission (control) 1261 Isg1 - -100 A dc Primary-grid emission (screen) 1266 Isg2 - -200 A dc See footnotes at end of table. Provided by IHSNot for ResaleNo reproduction or networking permitted without lic
9、ense from IHS-,-,-MIL-PRF-1/887E 3 TABLE I. Testing and inspection - Continued. Inspection Method Conditions Symbol Limits Unit MIL-STD-1311 Min Max Conformance inspection, part 3 - Continued Periodic-check tests Low-frequency vibration 1031 No voltages 5/ - - - - Low-frequency vibration end points:
10、 - Electrode voltage (grid) 1261 Ec1 -55 -80 V dc Total grid current 1266 Ic1 - -10 A dc Shock, specified pulse 1042 No voltages; accel = 15 G peak (min); D = 11 2 ms half-sine 5/ - - - - Shock, specified pulse end points: - Electrode voltage (grid) 1261 Ec1 -55 -80 V dc Total grid current 1266 Ic1
11、- -10 A dc 1/ Forced-air cooling shall be provided for the base-pin and anode-lead seals. This air should be applied simultaneously with filament power, using the 259-JAN socket. A minimum airflow of 14 cubic feet/minute shall be used. The pressure drop as measured in the socket at this flow equals
12、0.25 inches of water. The air requirements stated above are based on operation at sea level and on ambient temperature of 20C. Operation at high altitude or at high temperature requires a greater volume of airflow. 2/ Forced-air cooling of the anode and base seals to an extent not to exceed the mini
13、mum values specified in 1/ is permitted. 3/ It is recommended that a heat-radiating type of connector (EIMAC Type HR-6, or equivalent) be used on the anode terminal in all rf applications. 4/ This test is to be the first test performed at the conclusion of the holding period. 5/ Shock and vibration
14、tests shall be performed quarterly, 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; Separate samples may be used at the option of the manufacturer, and the tests shall be considered as nondestructive except in c
15、ase of failure. In case of failure after double sampling, the failing test shall become a conformance inspection, part 2, acceptance level 6.5, for three consecutive successful submissions, at which time the testing may revert to the periodic-check test basis. Provided by IHSNot for ResaleNo reprodu
16、ction or networking permitted without license from IHS-,-,-MIL-PRF-1/887E 4 NOTE: 1. Base pins T and tubulation K are so aligned that they can be freely inserted in a gauge .250 inch (6.35 mm) thick with hole diameters of .204 inch (5.18 mm) and .500 inch (12.70 mm) respectively, located on the true
17、 centers by the given dimensions S, U, and V. FIGURE 1. Outline drawing of electron tube type 8438. Ltr Dimensions Notes Inches Millimeters Min Max Min Max Conformance inspection, part 2 A 5.875 6.375 149.23 161.93 B - 3.563 - 90.50 K - .250 - 6.35 1 T .185 .191 4.70 4.85 1 Conformance inspection, p
18、art 3 (periodic check) D 5.125 5.625 130.18 142.88 E .350 .365 8.89 9.27 F .328 - 8.33 - J - .969 - 24.61 N - 2.750 - 69.85 Reference dimensions C .500 12.70 H .438 11.13 L .750 19.05 M .250 6.35 P .312 7.92 R 1.625 41.28 S 1.250 31.75 1 U 30 30 1 V 60 60 1 W 45 45 1 Provided by IHSNot for ResaleNo
19、reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/887E 5 Referenced documents. In addition to MIL-PRF-1, this specification sheet references: MIL-STD-1311 259-JAN The margins of this specification are marked with vertical lines to indicate where changes from the previous is
20、sue were made. This was done as a convenience only and the Government assumes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the requirements of this document based on the entire content irrespective of the marginal notations and re
21、lationship to the last previous issue. Custodians: Preparing activity: Army - CR DLA - CC Navy - EC Air Force - 99 (Project 5960-2012-013) DLA - CC Review activities: Army - AR, AV Navy - AS, CG, MC, OS, SH Air Force - 19 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-,-,-
