MIL-DTL-22931 Cables, Radio Frequency, Semirigid, Coaxial, Semi-Air-Dielectric, General Specification ForThis specification covers semi-air-dielectric, coaxial, semirigid radio frequency cables with smooth, corrugated, or braided outer conductors with outside diameters ranging from .500 to 3.125 inches, with an impedance of 50 or 75 ohms \(see 3.1\). The operating temperature ranges are -55 Degrees C to +80 Degrees C or -55 Degrees C to +200 Degrees C, as specified \(see 3.1\), and the storage temperature capability is -65 Degrees C.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19

MIL-DTL-22931D

4.5.4 Insulation defects, spark (when applicable, see 3.4.3). Jacketed cables shall be tested in

accordance with method 6211 of FED-STD-228. The following details shall apply:

a. The test voltage shall be a 60 Hz root-mean-square (rms) voltage as specified in table VII.

b. The potential shall be applied between the outer conductor and the outer surface of the jacket.

A puncture of the jacket by the applied voltage shall constitute a point of failure. The cable may

be cut at this point, or it may be repaired to the satisfaction of the Government.

TABLE VII. Voltage for spark test.

Jacket thickness

Voltage

(minimum)

(rms)

(inch)

0.035 (0.89 mm)

7,000

0.060 (1.52 mm)

9,000

0.065 (1.65 mm)

10,000

4.5.5 Insulation resistance (see 3.4.4). The cable shall be tested in accordance method 6031 of FED-

STD-228, except that the cable shall not be immersed in water but shall be tested dry. The following

details shall apply:

a. The test shall be performed on completed cable only.

b. The test voltage shall be not less than 200 volts.

c. The potential shall be applied to the inner conductor with the outer conductor grounded.

4.5.6 Attenuation (see 3.4.5). The attenuation, expressed in decibels (dB) per 100 feet, shall be

measured at a sufficiently low-power level that the resulting temperature rise will be negligible. An

acceptable method for measuring attenuation is as follows:

SIGNAL

GENERATOR

ATTENUATOR

DETECTOR

AND

CABLE

PAD

CALIBRATED

ATTENUATOR

In the block diagram, a suitable length of cable with an attenuation greater than the measuring

accuracy of the equipment is inserted between the connectors. The signal generator and calibrated

attenuator are adjusted to produce a reasonable indication at the detector, when the detector is

tuned. The detector reading is noted, and the calibrated attenuator output level is recorded. The

cable under test is when withdrawn and the circuit completed with the connectors (or a very short

length of cable). With the detector tuned, the calibrated attenuator is readjusted to reproduce the

original reading at the detector and the attenuator output level is again recorded. Attenuation is

then computed as follows:

100

(Difference in calibrated attenuator reading in dB)