Downloaded from https://www.everyspec.com MIL-STD-1311D METHOD 1041 SHOCK 1. Test equipment. The shock test shall be conducted on the Navy type, high-impact (flyweight) shock machine for electronic devices, or its equivalent (see Drawing 180-JAN). The standard steel hammer shall be used. The shock machine shall be so adjusted that the hammer at rest just contacts the anvil of the shock table. Each tube shall be subjected to a total of 20 hammer blows of the specified angular displacement or G level and duration. Application shall be five blows in axes X, Y, Z plus, and Z minus, in any sequence. The tube shall be mounted for testing as follows:
184-JAN 184-JAN 216-JAN or as specified 1/ The leads may be clipped. 2. Test conditions. The tubes shall be tested under one of the following conditions: a. With the voltages which are specified on the TSS applied to the tube. b. With a thyratron-controlled, short-circuit indicator with the circuit constants as shown on figure 1041-1, or its equivalent, connected to indicate interelectrode shorts. Tubes shall have rated filament or heater voltage applied. c. No voltages applied. 3. Failure criteria. Tubes which show one or more of the following defects shall be considered failures: a. Tubes which show permanent shorts during the shock tests. b.
Tubes which show tap or permanent shorts or open circuits following shock tests. c. Tubes which do not comply with shock test end point limit(s). 4. Test classification. This is a destructive test. Size of tube Clamp drawing Miniature Subminiature 1/ T9 and larger Ecc should be adjusted to indicate a short with a 50,000-ohm resistor and to give no indication with 75,000 ohms. The firing voltage Ec should not be outside the range of 1.0 to 3.0 volts. FIGURE 1041-1. Short-circuit indicator. METHOD 1041 1041-1 19 April 1968