Technical Dictionary of Engineering Terms
"A" "B" "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
"N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"


Defines both RG11 and RG12 which both operate up to 1GHz. Both cable types have an inner conductor diameter of 0.0477 inches, and a characteristic impedance of 75 ohms [with a variation of 3 ohms].

RG12 Cable Diagram per MIL-DTL-17/6
75 Ohm RF Shielded Coax

RG12. 75 Ohm Flexible RF Coaxial Armored Cable.
The cable is covered by MIL-DTL-17/16 [M17/6-RG12], however because that specification used PVC jacket, the spec is inactive for new designs, MIL-C-17/181 [below] should be used. The outer diameter of the armor used with RG12 is 0.475 inches.

RG11. MIL-DTL-17/16-RG11 uses the same specification but with out the armor, also with a PVC jacket. Both RG11 and R12 have an inner conductor consisting of seven strands of copper wire with an overall diameter of 0.0477 inches. The outer diameter of the jacket used with RG11 is 0.405 inches.


M17/181-00002 Armored Cable Diagram
MIL-C-17/181 Armored Cable

M17/181-00002. 75 Ohm Flexible RF Armored Coaxial Cable.
Both of these cables use a polyolefin jacket instead of PVC jacket.
Note that this cable uses a barrier tape between the jacket and outer conductor.
.. Weight; 10.8 pounds per 100 feet maximum
.. Attenuation; 5.2dB per 100 feet at 0.4GHz
M17/181-00001. 75 Ohm Flexible RF UnArmored Coaxial Cable.
.. Weight; 13.2 pounds per 100 feet maximum
.. Attenuation; 5.2dB per 100 feet at 0.4GHz

Note, even though RG12 cable may still be purchased under that name, the term RG12 is out dated. The abbreviation is obsolete and should no longer be used.
Do not use the RG abbreviation in a requirements document or specification. The 'R' in RG means Radio Frequency, and the 'G' means Government.

The department of defense specification may or may not be currently valid. The government could withdraw this standards at any time, or they could transfer the requirement to another specification. In addition the slash sheets detailing individual cable requirements may also be withdrawn with out notice.

How to read the cable number:
The over-all standard defining the general requirements is; MIL-C-17
The slash sheet or individual cable standard is /181
The possible cable variants are given as -00001 or -00002

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