MIL-PRF-1/1753C
TABLE I. Testing and inspection - Continued.
Limits
Method
Inspection
Unit
Notes
Test
Conditions
Symbol
MIL-STD-1311
Min
Max
Conformance
inspection, part 3
29/,
Group D; VSWR = 1.5 cycled
1, 2
1250
---
hours
Life test
through λg every 15 minutes
30/
1500
---
cycles
(approximately)
2/
Life-test end points:
4250
2
Po
70
---
W
Power output
2.5/tpc MHz
21/
4308
1, 2
BW
---
RF bandwidth
21/
---
4308
1, 2
Ratio
6
dB
Minor lobes
Stability
4315
17/
2
MP
---
0.5
%
1/
The acceptance level for all tests listed under conformance inspection, part 1, shall be accept on zero failures.
2/
If during life test, the tube does not meet the specified limits, it shall be recycled for an additional five cycles. At
such time, the tests shall be repeated. The tube will be considered satisfactory if it passes the second test.
3/
The tuning mechanism shall be capable of withstanding a static torque of 75 inch-ounce at the ends of its travel.
4/
The tube shall be capable of normal operation without electrical breakdown with the input bushing in air at
normal atmospheric conditions.
5/
Prior to the application of high voltage, the cathode shall be heated to the required initial operating temperature.
This shall be done by applying 13.75 volts ±5 percent for 150 seconds, minimum. On the application of anode
voltage, the heater voltage shall be reduced in accordance with the following schedule:
Ef = 13.75 (1 - Pi ) ±5 percent; for Pi = 0 to 370 watts, where Pi = epy x Ib.
675
6/
The characteristics of the applied pulse shall be those which result in proper starting and oscillation. The rate of
rise of the voltage pulse, the percentage of pulse voltage ripple, and the rate of pulse voltage fall are among the
most important considerations.
7/
The rate of voltage (rrv) shall be expressed in kilovolts per microsecond (kV/µs) defined by the steepest tangent
to the leading edge of the voltage pulse above the 70 percent amplitude point. Any capacitance used in the
viewing (measuring) circuit shall not exceed 6 picofarads (pF).
8/
In handling and mounting the magnetron, care shall be exercised to prevent demagnetization. See figure 1. The
use of magnetic inspection tools is prohibited.
9/
With a total airflow of approximately 20 cfm at approximately 760 mmHg, 25ºC divided equally and directed
through the cooling fins toward the body of the tube from two ducts placed 0.750 inch (19.05 mm) maximum from
cooling fins, the specified rise above ambient temperature shall not be exceeded.
10/ Temperature measurements shall be made only after thermal equilibrium has been reached. The frequency
shall be measured at the extremes of any 30ºC temperature difference in the specified temperature range.
11/ The tube shall be subjected to five shocks of the specified peak amplitude and duration in each of three mutually
perpendicular directions. Following impact tests, the tube shall show no mechanical failure and shall meet the
power output and pulse voltage requirements of conformance inspection, part 1.
4
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business