1、 MIL-PRF-1/1470E 27 July 2009 _ SUPERSEDING MIL-PRF-1/1470D(EC) 25 June 1999 PERFORMANCE SPECIFICATION SHEET ELECTRON TUBE, MICROWAVE (NEGATIVE GRID) TYPE 7698 This specification is approved for use by all Departments and Agencies of the Department of Defense. The requirements for acquiring the elec
2、tron tube described herein shall consist of this document and the latest issue of MIL-PRF-1. DESCRIPTION: Triode, planar, ceramic-metal. See figure 1. Mounting position: Any. Weight: 1.8 ounces (48 grams) nominal. ABSOLUTE RATINGS: Parameter: F Ef Eb epy Ec ib Ib ic tp Du Unit: GHz V V dc kv V dc a
3、mA dc a s - Maximum: Anode pulsed (Osc or amp) 3.0 6.3 5% 1/ 12/ - 3.5 -150 5 2/ - 2.5 3.5 0.0025 Grid pulsed (Osc or amp) 3.0 6.3 5% 1/ 12/ 2,000 - -150 5 2/ - 2.5 3.5 0.0025 Test conditions: - 6.3 600 - Adj - 25 - - - ABSOLUTE RATINGS: Parameter: Pp Pg tk TE T(anode shank) Barometric pressure redu
4、ced Cooling Unit: W W sec (min) C C mmHg - Maximum: Anode pulsed (Osc or amp) 10 2 3/ 60 250 4/ 250 4/ 35 5/ 4/ Grid pulsed (Osc or amp) 10 2 3/ 60 250 4/ 250 4/ 35 5/ 4/ Test conditions: - - 300 - - - 6/ See footnotes at end of table I. _ GENERAL: Qualification: Required. AMSC N/A FSC 5960 INCH-POU
5、ND Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1470E 2 TABLE I. Testing and inspection. Inspection Method Notes Conditions Acceptance SymbolLimits Unit MIL-STD-1311 Level 20/ Min Max Conformance inspection, part 1 Insulation of electrod
6、es 1211 7/ - Eb = Ek = 0; Ec = -500 V dc 0.65 R 50 - MegPower oscillation (pulse) 1236 8/ 9/ F = 3.0 GHz (min); epy = 3.5 kv; Ec = -1.5 V (min); Rg/Ib = 12 mA dc (max);Ef = 5.8 V 0.65 Po 6.0 - W Electrode voltage (1) (grid) 1261 6/ 0.65 Ec -4.5 -9.5 V dcTotal grid current 1266 6/ 0.65 Ic - -2.0 A dc
7、Pulsing emission 1231 - eb = ec = etd/is = 10 a; tp = 3 s (max); prr = 600 (max) 0.65 etd - 180 v Heater current 1301 - 0.65 If 1.20 1.40 A Conformance inspection, part 2 Direct-interelectrode capacitance 1331 9/ No voltages applied; use fixture in accordance with Drawing 158-JAN - Cgk Cpg Cpk 7.00
8、2.10 - 9.00 2.40 0.06 pF pF pF Resonance - 9/ 11/ No voltages applied - - - - - Electrode voltage (2) (grid) 1261 - Ec/Ib = 1.0 mA dc; Eb = 1,000 V dc - Eco - -30 V dcPower gain - 13/ F = 1,100 50 MHz; Ebb = 2,200 V dc (min); Ecc = -50 V dc; tp = 3 s (min); Du = 0.002 (min); pd = 400 w - po 1.8 - kW
9、 See footnotes at end of table. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1470E 3 TABLE I. Testing and inspection - Continued. Inspection Method Notes Conditions AcceptanceSymbolLimits Unit MIL-STD-1311 Level 20/ Min Max Conformance i
10、nspection, part 3 Life test - 10/ Group C; t = 500 hours; filament standby; Ef = 6.3 V ac - - - - - Life-test end point - 10/ - ib - 25 % Variable-frequency vibration - 9/ 14/ 15/ 55 to 500 Hz at 10 G peak; Ec/Ib = 10 mA dc; Rp = 10,000 ohms; Ebb = 300 V dc - Ep - 250 mV acTorque - 9/ 15/ 16/ No vol
11、tages applied - - - - - Shock - 9/ 15/ 17/ 60 G peak (min); 11 2 ms; no voltages applied - - - - - Torque-and shock test end point: - Total grid current 1266 - - Ic - -10 A dcBarometric pressure, reduced 1002 15/ 18/Pressure = 35 mmHg (max); voltage = 2,000 V ac; TA = 30C 10C - - - - - 1/ The transi
12、t time heating effect of the cathode shall be compensated by a reduction in heater voltage after dynamic operation of the tubes has started. The back heating is a function of frequency, grid current, grid bias, anode current, duty cycle, and circuit design and adjustment. There is an optimum heater
13、voltage which will maintain the cathode at the correct operating temperature for a particular set of operating conditions. A maximum variation of 5 percent from optimum is permitted. No reduction in heater voltage is required up to and including 500 MHz. 2/ The regulation or series-anode-supply impe
14、dance, or both, shall limit the instantaneous peak current, with the tube considered as a short circuit, to a maximum of 10 times the specified maximum current rating. 3/ The maximum instantaneous peak grid-cathode voltage shall be within the range of +250 to -750 volts. 4/ Sufficient conduction and
15、 convection cooling shall be provided to limit the envelope and anode shank temperature to the specified maximum value under all operating conditions. Reliability will be seriously impaired if this maximum is exceeded. Where emphasis is placed on long and reliable life, lower temperatures shall be u
16、sed. 5/ Operation at this altitude is possible in a suitably designed circuit. 6/ Sufficient conduction, convection, and forced-air cooling shall be used in all electrical tests involving application of heater voltage to maintain the anode shank and seal temperatures within the specified maximum val
17、ues. 7/ All tests listed under conformance inspection, part 1, shall be performed at the conclusion of the holding period. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1470E 4 TABLE I. Testing and inspection - Continued. 8/ The applied v
18、oltage pulse shape shall be measured with a noninductive resistor of 1,150 ohms 2 percent inserted in place of the tube. The pulse shape shall be tp = 3.0 s 10 percent, tr = 0.4 s (max), tf = 0.7 s (max). The pulse repetition rate shall be adjusted so that Du = 0.0025 5 percent with the above measur
19、ed pulse length. Test in cavity in accordance with Drawing 279-JAN. The cavity shall be connected to a load with a VSWR less than 1.5. The oscillator output coupling and the grid or cathode resistor may be adjusted for maximum power output. 9/ Other tube contact configuration may be used provided th
20、e tube contact area remains unchanged and the socket, jig, or cavity gives equal performance. Mounting of the socket, jig, or cavity may be at the option of the manufacturer. 10/ At zero hours, establish the drive conditions necessary to obtain 3.0 amperes peak anode current with an anode voltage of
21、 1,000 V dc and a bias voltage of -40 V dc. The pulse width of the modulator shall be 2 s (minimum) and the duty shall be 0.0025 maximum. With the drive level determined at zero hours, check the anode current at the end of life. The maximum allowable drop in anode current is 25 percent. 11/ Grid-ano
22、de resonance: Test in cavity in accordance with Drawing 278-JAN. Cavity shall resonate at 1,354 2 MHz with tuning lug in accordance with Drawing 277-JAN at TA = 25C 5C. Grid-cathode resonance: Test in cavity in accordance with Drawing 283-JAN. Cavity shall resonate at 1,719 2.0 MHz with tuning slug
23、in accordance with Drawing 277-JAN at TA = 25C 5C. When plotted on graphs of resonant frequency versus grid-anode capacitance and resonant frequency versus grid-cathode capacitance, the tube under test (TUT) shall be represented by a point within a parallelogram whose four corners are located by the
24、 following points: Point Capacitance (pF) Frequency (MHz) C-gp C-gk F-gp F-gk 1 2.10 7.0 1,935 1,765 2 2.10 7.0 1,965 1,795 3 2.40 9.0 1,870 1,725 4 2.40 9.0 1,900 1,755 12/ Where emphasis is placed on long and reliable life, the filament voltage can safely be lowered to 6.0 volts, provided the line
25、 voltage is regulated better than 2 percent. 13/ Test shall be conducted in a power amplifier cavity as shown on figure 2. Driving power is defined as the net power delivered to the amplifier input terminals and the reflected power shall be subtracted from the incident power to obtain the net drivin
26、g power. The output tuning shall be adjusted for maximum power output. 14/ The TUT shall be mounted in a socket in accordance with Drawing 276-JAN and vibrated with simple harmonic motion. The peak acceleration over the frequency range shall be within 20 percent of the reference acceleration at 100
27、Hz. The frequency shall vary from 55 to 500 Hz and return to 55 Hz with approximately logarithmic progression and shall require 4 minutes minimum, 6 minutes maximum, to traverse the range. Each tube shall be vibrated for 30 minutes in each axis X and Z except that if the cumulative result of tests o
28、n 50 or more tubes of a construction show that more than 75 percent of the tubes have higher output voltages in one position, subsequent measurements need be taken only in the axis giving the higher reading. The voltages specified herein shall be applied to the tube during vibration. The value of th
29、e alternating voltage Ep, produced across the resistor Rp, as a result of vibration shall be measured with a suitable device. This device shall have an appropriate voltage range and shall have the ability to measure, with an error of less than 10 percent, the rms value of a sine wave of voltage at a
30、ll frequencies from 20 to 20,000 Hz. The value of the vibrational output Ep shall not exceed the limit specified herein at any point in the sweep-frequency range during the last complete cycle of cycling vibration. Provided by IHSNot for ResaleNo reproduction or networking permitted without license
31、from IHS-,-,-MIL-PRF-1/1470E 5 TABLE I. Testing and inspection - Continued. 15/ This test shall be performed during the initial production and once each succeeding 12-calendar month period in which there is production. A regular double sampling plan shall be used, with the first sample of three tube
32、s having an acceptance number of zero, and a second sample of three tubes having a combined acceptance number of one. In the event of failure, the test shall be made as a part of conformance inspection, part 2, inspection level S3, with an acceptance level of 6.5. The regular “12 calendar month” dou
33、ble sampling plan shall be reinstated after three consecutive samples have been accepted. 16/ The torque test shall be performed as follows: a. The TUT shall be held securely at the cathode connection. A force of 5 pounds shall be applied to the heater cup without perceptible shock. This test may be
34、 made by applying the force at right angles to the inside of the cup at a point .109 inch (2.78 mm) .016 inch (0.40 mm) from the cathode end of the tube. An approved equivalent method may be used. The heater cup shall not loosen or short circuit on the cathode connection. This part of the test shall
35、 not be required if the space between the heater cup and the cathode sleeve is completely filled with insulating material. b. A torque of 15 inch-pounds shall be applied between anode and cathode without shock. c. A torque of 40 inch-pounds shall be applied between anode and grid without shock. 17/
36、Test in jig made in accordance with Drawing 280-JAN. Each tube shall be subjected to a total of 15 shocks; that is, 5 shocks in each axis Y, +Z, -Z in any sequence as shown on figure 1. 18/ Voltage shall be 60 Hz ac applied between anode and grid. No other voltages shall be applied. There shall be n
37、o evidence of failure as indicated by arc-over 19/ Revision letters are not used in this revision to identify changes with respect to the previous issue, due to the extensiveness of the changes. 20/ This specification sheet uses accept on zero defect sampling plan in accordance with MIL-PRF-1, table
38、 III. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1470E 6 FIGURE 1. Outline drawing of electron tube type 7698. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-1/1470E 7 Dimensio
39、ns Ltr Inches Millimeters Notes Min Max Min Max Conformance inspection, part 2 A 1.815 1.875 46.10 47.62 B - 1.534 - 38.96 C - 1.475 - 37.46 D 1.289 1.329 32.74 33.76 F .970 1.010 24.64 25.65 G .462 .477 11.73 12.12 J .766 .826 19.46 20.98 N 1.025 1.035 26.04 26.29 5, 13 R .655 .665 16.64 16.89 5, 1
40、3 T .213 .223 5.41 5.66 6, 13 U .315 .325 8.00 8.26 5, 6, 13 Conformance inspection, part 3 7 H - .040 - 1.02 K - .185 - 4.79 M 1.180 1.195 29.97 30.35 P .752 .792 19.10 20.12 S - .545 - 13.84 V - .086 - 2.18 W - .100 - 2.54 LA .840 .860 21.34 21.84 ZA .427 .447 10.85 11.35 Electrode contact areas 1
41、4 AA .035 .361 0.89 9.17 1, 5 AB 1.185 1.265 30.10 32.13 2, 5 AC 1.534 1.728 38.96 43.89 3, 6 AD 1.475 1.815 37.46 46.10 4, 5, 6 FIGURE 1. Outline drawing of electron tube type 7698 - Continued. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF
42、-1/1470E 8 NOTES: 1. Anode rf contact surface and reference dimension for eccentricity measures. 2. Grid rf contact surface and reference dimension for eccentricity measurements. 3. Heater contact surface and reference dimensions for eccentricity measurements. 4. Heater and cathode rf contact surfac
43、e and reference dimensions for eccentricity measurements. 5. The total indicated runout of the anode and grid contact surface with respect to the cathode contact surface shall not exceed .020 inch (0.51 mm). 6. The total indicated runout of the cathode contact surface with respect to the heater cont
44、act surface shall not exceed .012 inch (0.30 mm). 7. These dimensions shall be tested on 10 tubes per month when in continuous productions. Failure of more than one tube to meet tolerances for any dimension shall cause that dimension to become, for all lots in process, part of conformance inspection
45、, part 2. 8. Silver plated 30 MSI minimum. 9. Plating not required over radiator or handle support of copper, aluminum, or approved equivalent. 10. This surface shall be used for measurement of anode shank temperature. 11. Inner edge of heater and outer edge of cathode rf connections shall be free f
46、rom burrs and sharp edges. Insulation material between heater and heater-cathode shall be securely affixed. 12. Total indicated runout (T.I.R.) of contact surfaces shall be gauged from center line of reference and shall be as follows. Note 7 shall apply. Contact surface T.I.R. (maximum) Reference An
47、ode .020 Cathode Grid .020 Cathode Heater .012 Cathode 13. Diameters N, R, T, and U shall apply throughout entire contact areas as defined by dimensions AA, AB, AC, and AD, respectively. 14. Dimensions in electrode contact areas table are for socket design purposes and are not intended for inspection purposes. FIGURE 1. Outline drawing of electron tube type 7698 - Continued. Provided by IHSNot for ResaleNo reproduction or
