ARC-182\(V\) radio set. The antenna is an aircraft fuselage mounted blade enclosed element. The antenna is a broadband, fix tuned, exhibits omnidirectional radiation pattern, and is vertically polarized for radiating and receiving radio waves in the 30-88 MHz, 108-174 MHz, and 225-400 MHz communication bands.

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MIL-DTL-85670D

4.5.4.5.1 Test item operation. VSWR shall be monitored during application of random vibration so that the

functional effects may be evaluated. The test item shall meet VSWR requirements, as specified, while the functional

vibration levels are being applied and immediately preceding and following the application of the endurance levels.

4.5.4.5.2 Mounting techniques. The test item shall be attached by its normal mounting means, either directly to the

vibration exciter or transition table, or by means of a rigid fixture capable of transmitting the vibration conditions

specified herein. The input control sensing device(s) shall be rigidly attached to the vibration table, or fixture if used,

as near as possible to the attachment point(s) of the test item.

4.5.4.5.3 Performance of test. The antenna shall be subjected to the durations and vibration levels of 4.5.4.5.4

4.5.4.5.4 Test duration. The random vibration test requires two levels, function level and an endurance level. For

each axis, one half of the functional test shall be conducted first, then the endurance test, followed by the second half

of the functional test. The antenna shall perform according to the specified operating requirements of 4.5.3.2. The

acceleration power spectral density (g /Hz) of applied vibration, as measured on the test fixture at mounting point of

the test item, shall be as specified in 4.5.4.5.5. Test times shall, for each axis, be one hour each for functional and

endurance levels. The instantaneous random vibration acceleration peaks may be limited to three times the rms

acceleration level. The power spectral density of the best control signal shall not deviate from the specified

requirements by more than +100, -50 percent (+3, -3 dB) between 500 Hz and 2,000 Hz except that deviations as

large as +300, -75 percent (+6, -6 dB) shall be allowed over a cumulative bandwidth of 100 Hz maximum, between

500 and 2,000 Hz.

4.5.4.5.5 Vibration levels. The following minimum test levels shall be used:

Functional level: 6.79g rms minimum in accordance with the vibration envelope of figure 2.

Endurance level: 12.1g rms minimum in accordance with the vibration envelope of figure 3.

4.5.4.6 Sideloading. The antenna shall be subjected to a design limit side loading test followed by an ultimate side

loading test.

4.5.4.6.1 Design limit test. The antenna shall be normally mounted and subjected to a pressure of 5.3 PSI for a

minimum of 4 applications. The pressure shall be applied over the entire surface area of either side of the antenna.

The deflection of the tip of the antenna shall be measured as the pressure is applied. Full pressure shall be attained

within approximately one minute and maintained for one minute. The antenna tip deflection versus time shall be

plotted. The pressure shall be applied in a similar manner to the remaining side. This cycle shall be repeated. All

four plots shall be similar and display no sharp breaks or angularity. There shall be no physical damage, distortion, or

permanent set. Any damage indicated, either internal or external, shall be considered a failure. Following the test,

the antenna shall comply with electrical performance requirements of 3.6.4.

4.5.4.6.2 Ultimate limit test. Following the design limit test, the antenna shall be subjected to the ultimate limit test.

All conditions shall be the same as for the design limit test with the following exceptions:

The applied pressure shall be 8 PSI.

The pressure shall be applied once to each side.

Damage is acceptable as long as no pieces separate from the test specimen.