1、 MIL-PRF-1/1688C 4 August 2009 _ SUPERSEDING MIL-PRF-1/1688B(USAF) 25 June 1999 PERFORMANCE SPECIFICATION SHEET ELECTRON TUBE, MAGNETRON TYPE 8798 This specification is approved for use by all Departments and Agencies of the Department of Defense. The requirements for acquiring the electron tube des
2、cribed herein shall consist of this document and the latest issue of MIL-PRF-1. DESCRIPTION: Pulsed, tunable frequency range 2.7 GHz to 2.9 GHz, rated peak power output 800 kW, external magnet, coaxial line output, forced-air cooled. ABSOLUTE RATINGS: Parameter: Unit: Ef V epy kv ib a Pi W pi kW tp
3、sec Maximum: Minimum: 17 - 1/ 32 - 70 - 1,300 - 200 - 2.5 - Parameter: Unit: Du - tk sec VSWR - Anode T C rrv kV/s Alt. Ft Maximum: Minimum: .0011 00 - 120 1.35 - 120 - 150 - 12,000 - PHYSICAL CHARACTERISTICS: Dimensions: Weight: Mounting position: Cathode: See outline drawing. 6.5 pounds approximat
4、ely. Any. Unipotential. TEST CONDITONS: Parameter: Unit: Ef V Magnetic field H tpc sec Du - rrv kV/s prr - tk sec Test 1: Test 2: Test 3: Tolerance: - - 10 5% 1/ 2,700 2,700 2,700 50 4/ 0.7 2.0 1.0 0.1 .0007 .0007 .001 - 110 110 150 - 1,000 350 1,050 - 180 180 - - Parameter: Unit: tfc sec trc sec tr
5、v sec VSWR - Ib mA dc Test 1: Test 2: Test 3: Tolerance: 0.50 0.50 0.50 0.10 0.125 0.125 0.125 0.045 0.15 0.15 0.15 0.05 1.15 max 1.15 max 1.35 max - 46 46 39.5 5% See footnotes at end of table I. GENERAL: Qualification - Required. AMSC N/A FSC 5960 INCH-POUND Provided by IHSNot for ResaleNo reprodu
6、ction or networking permitted without license from IHS-,-,-MIL-PRF-1/1688C 2 TABLE I. Testing and inspection. Limits Inspection Method MIL-STD-1311 Test Conditions Symbol Min Max Unit Qualification inspection High frequency vibration 1031 - No voltages 7/ - - - - Temperature coefficient 4004 1 F1, F
7、2, and F3 T = 60C to 90C F/T - 70 kHz/A Low temperature 1026 - tk = 180 sec MP - 1 % Conformance inspection, part 1 Dimensions D-30(b) - See figure 1 - - - - Pressurizing 4003 - 42.5 2.5 lbf/in2- - - - Heater current nonoperating 4289 - Ef = 16.0 V 5 %; tk = 300 sec (min) 1/ If 2.6 3.1 A Pulse volta
8、ge 4306 1 F1, F3 epy 26 32 kv Power output (1) 4250 1 F2, F3 Po 525 - W Power output (2) 4250 2 F1 Po 525 - W RF bandwidth 4308 1 F1, F2, F3 BW - 2.5/tpc MHz Minor lobes 4308 1 F1, F2, F3 Ratio 8 - dB Stability 4315 1 F1, F2, F3 MP - 0.5 % Mechanical tuning range 4223 1 1 Low frequency High frequenc
9、y F1 F3 - 2.9 2.7 - GHz GHz Power output (3) 4250 3 F1 and F3 Po 470 - W Stability 4315 2 6/ MP - 0.5 % Conformance inspection, part 2 Pushing factor 4311 3 F2 Ratio - 125 kHz/A Pulling factor 4310 1 Ib = 28 mA dc to 46 mA dc; F2 F - 15.0 MHz Operating torque or force 4223 - 8/ Torque - 20 ounce-inc
10、h Dimensions D-30(b) - See figure 1 - - - - See footnotes at end of table. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1688C 3 TABLE I. Testing and inspection - Continued. Limits Inspection Method MIL-STD-1311 Test Conditions Symbol Min
11、 Max Unit Conformance inspection, part 3 Life test - 1 Group S; F2 t 1,000 - hrs Life test end points: - Power output 4250 1 F1, F2, and F3 Po 420 - W RF bandwidth 4308 1 F1, F2, and F3 BW - 3.0/tpc MHz Stability 4315 1 F1, F2, and F3 MP - 1.0 % Minor lobes 4308 1 F1, F2, and F3 Ratio 7 - dB 1/ Stan
12、dby or preheat heater voltage shall be 16.0 V dc 5 percent. During high voltage operation, heater voltage should be adjusted to the following approximate values: Pi (watts) Ef (Vdc) 1,200-1,400 5.5 1,000-1,200 8 800-1,000 10.5 600-800 13 400-600 15 0-400 16 2/ These periodic check tests which have b
13、een performed and have met specified requirements within 36 months need not be performed if test requirements, material, or manufacturing processes have not changed in the interim. 3/ The value of VSWR specified excludes the tube coupling adapter. 4/ The magnetic field should be calibrated in accord
14、ance with the following procedure. See figure 2. a. With conventional 1/8 inch pole piece attached to the pole face of the magnet opposite the magnetron tuner, the magnetic gap should be 1.800 inches. b. The magnetic field should then be adjusted for 2,700 gauss at the center of the gap. c. Remove t
15、he conventional 1/8 inch pole piece and replace it with the distortion pole piece. 5/ Frequency definitions: F1 = 2.7 GHz F2 = 2.8 GHz F3 = 219 GHz 6/ Missing pulses shall be counted during the last three minutes of a stability test interval not to exceed 6 minutes. The stability test interval shall
16、 first be conducted at F1 and shall be started no later than 10 minutes after the application of high voltage. Test intervals shall then be conducted consecutively at F2 and F3. 7/ Following this test, the magnetron shall be capable of normal operation under test condition 1. 8/ Tuning mechanism wil
17、l provide full range of tuning with five 360 turns, maximum. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1688C 4 FIGURE 1. Outline drawing of electron tube type 8798. Provided by IHSNot for ResaleNo reproduction or networking permitted
18、without license from IHS-,-,-MIL-PRF-1/1688C 5 OUTLINE DIMENSIONS SIMILAR TO 242-JAN (REF) Dimensions Dimensions Ltr Inches Millimeters Ltr Inches MillimetersMin Max Min Max Min Max Min MaxConformance inspection, part 1 AU 1130 1630 1130 1630E - 2.156 Nom - 54.76 Nom AV - .313 Nom - 7.95 NomF - 1.35
19、9 Nom - 34.52 Nom AW - 2.812 Nom - 71.42 NomL - 1.437 Nom - 36.50 Nom Conformance inspection, part 2 N 1.417 1.457 36.00 37.01 A 2948 3012 2948 3012R - 1.440 Nom - 36.58 Nom B .205 .215 5.21 5.46T - 3.500 Nom - 88.90 Nom C 4448 4512 4448 4512X - 1.437 Nom - 36.50 Nom D 2948 3012 2948 3012Z - .756 No
20、m - 19.20 Nom G 2948 3012 2948 3012AC 2.287 2.307 58.09 58.60 H 4448 4512 4448 4512AD 2.060 2.110 52.32 53.59 J 2.266 R 2.296R 57.56 R 58.32 RAE 1.125 - 28.57 - K 2948 3012 2948 3012AF 2.314 2.328 58.77 56.84 M 2.029 R 2.035 R 51.54 R 51.69 RAG .550 .560 13.97 14.22 P .500 - 12.70 -AH 1.420 1.460 36
21、.07 37.08 S 1.063 - 27.00 -AJ - 1.620 - 41.15 U - 2.656R - 67.46 RAL 2 1/2-18 NS-2A 2 1/2-18 NS-2A V 30 35 30 35AN - .187 Nom - 4.75 Nom W 1.500 R - 38.10 R -AP .438 .688 11.12 17.47 Y 1.500 - 38.10 -AR .525 .625 13.33 15.87 AB .803 .833 20.40 21.16AS - .025 Nom - 0.64 Nom AK .593 - 15.06 -AT - 1.74
22、0 - 44.20 AM 6.219 6.407 157.96 162.74NOTES: (MECHANICAL REQUIREMENTS) 1. The periphery of the anode shall lie within a 2.160 inch (54.86 mm) diameter circle located as specified for non-tunable side of anode. 2. Maximum width specified applies to area defined by broken line and circumference of rad
23、iator. 3. Center-line of maximum diameter shall be concentric with center-line of guard pipe to within 0.040 inch (1.02 mm). 4. Applies to inner conductor insert only center-line of inner conductor insert shall be concentric with center of guard pipe to within 0.025 inch (0.64 mm). 5. Applies to str
24、aight portion of inner conductor wall. 6. No sharp edges of outside diameter at end of inner conductor. 7. Tube may be supported by plate (mounting) or guard pipe. 8. Spline for adjusting tuning mechanism is as follows: 12 teeth 48 pitch - 0.250 inch (6.35 mm) pitch diameter. 9. This annular area sh
25、all be flat within 0.015 inch (0.38 mm) (a thickness gauge 0.125 inch (3.18 mm) wide shall not enter more than 0.250 inch (6.35 mm). 10. Pyrex glass or approved equivalent. 11. Leads shall be flexible and slack. 12. Tuning mechanism will provide full range of tuning with five 360 turns, maximum. 13.
26、 Protective guard for shipping purposes. 14. The center of the jack holes shall be within a radius of 0.100 inch (2.54 mm) of the location specified but shall be spaced 0.797 inch (20.24 mm) 0.015 inch (0.38 mm) with respect to each other. 15. Common cathode connection marked with letter “C”: 16. He
27、x locking head banana pin jack 0.594 inch (15.09 mm) long, hole 0.169 inch (4.29 mm) 0.005 inch (0.13 mm). 17. Paint with heat-resistant non-corrosive paint; the following shall be free from paint-top surface of mounting plate parts above mounting plate, screw threads on guard pipe and all surfaces
28、inside guard pipe, tuning gear, stop assembly, and worm shaft Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1688C 6 assembly. 18. Applies to location of center of guard pipe only. 19. Clearance to adapter guard pipe must be sufficient to
29、allow use of S. S. White Co. No. 2666X end fitting (13/32 diameter). 20. All solder joints on mounting plate and guard pipe shall be soldered to provide a hermetic seal. 21. Optical location of tuning spline, tube to be supplied with spline located as specified by customer. 22. This dimension shows
30、relation between a plane passing through lateral center of anode and a plane through center of guard pipe. 23. Reference plane “A” is defined as a plane passing along the face of the mounting plate. 24. Reference plane “B” is defined as a plane perpendicular to plane “A” passing through the center o
31、f the holes as shown. 25. Reference plane “C” is defined as a plane mutually perpendicular to planes “A” and “B” passing through the center of the hole as shown. 26. The letter “A” has been added to indicate external thread, not unified thread. Provided by IHSNot for ResaleNo reproduction or network
32、ing permitted without license from IHS-,-,-MIL-PRF-1/1688C 7 NOTE: Dimensions are in inches. Metric equivalent values are provided for information only and is based upon 1 in. = 25.4 mm. Unless otherwise specified, tolerances are 0.03. FIGURE 2. Magnetic field calibrators for electron tube type 8798
33、. Dimensions Ltr Inches Millimeters Min Max Min Max A #10-32 flat head screw-brass #10-32 flat head screw-brass B - .03 - 0.8 C .125 REF 3.18 REF D 1.795 1.805 45.59 45.85 E 1.63 (TYP) DIA 41.40 (TYP) DIA F 1.920 1.930 48.77 49.02 G #10-32 Flat head screw-steel (3 places) #10-32 Flat head screw-stee
34、l (3 places) H 2.25 (TYP) DIA 57.15 (TYP) DIA J .312 DIA Hole CSK 7.92 DIA Hole CSK K - .786 - 19.96 L - 2.000 - 50.80 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1688C 8 Referenced documents. In addition to MIL-PRF-1, this document ref
35、erences the following: 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. Bidders an
36、d 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: Air Force - 85 DLA - CC DLA - CC Review activities: (Project 5960-2009-028) Air Fo
37、rce - 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 http:/assist.daps.dla.mil/. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
