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本帖最後由 WSUgocouars 於 2012-1-11 20:31 編輯
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★★★★商品說明★★★★
MIL-C-17
INTRODUCTION:
MIL-C-17 is the government specification used to standardize Mil-Spec Coaxial Cables. The “RG” part numbers
have been superseded by M-17 part numbers. The most recent revision to MIL-C-17 is the revision “G.” Cables
to this revision are available in swept or unswept frequency measurements and Low Smoke jackets. Cables
must be procured from QPL sources when QPL listing exists.
APPLICATIONS:
Radio frequency coaxial cables conforming to military specifications.
Benefits in Using MIL-C-17 Coaxial Cables: In 1976, Revision “E” to MIL-C-17 was released to better define
the electrical and mechanical properties for Mil-Spec Coaxial Cables. The most important changes for 50
ohm cables were the addition of swept frequency measurements of both structural return loss (VSWR) and
attenuation. Before Revision “E” there were no (VSWR) requirements and the attenuation requirements were
only given at two or three frequencies.
Adhesion Requirements: Prior to Revision “E” it was possible in shorter cable lengths to pull the center
conductor out of the body of the entire assembly during the stripping operations, or there could be too much
adhesion between the core and the center conductor causing the conductor to break before the dielectric
could be stripped off. M-17 specifications now contain maximum and minimum adhesion requirements of the
dielectric core and center conductor.
Dimensional Stability: Temperature extremes can cause shrinkback of the cable jacket which can create
a poor termination. All cables manufactured and tested to Revision “E” have specified maximum shrinkback
allowance for the dielectric core and jacket.
Stress-Crack Resistance: A stress-crack resistance test is now required under M-17 on all FEP (fluorinated
ethylene propylene) and PFA (penfloraolkoxy) jacketed cables. This test identifies cables with previously
undetected residual stress that could result in jacket cracking.
Contamination: M-17 Revisions “F” and “G” have completely replaced Type IA PVC with Type IIA PVC, a
noncontamination compound. The plasticizers in Type IA PVC jackets can penetrate the braid shield and
migrate into the polyethylene dielectric core causing a large increase in the dielectric loss portion of attenuation.
Coaxial cables with a Type IA PVC jacket can affect other cables in close contact even if the other cables
have a Type IIA jacket.
Attenuation and Structural Return Loss: A (VSWR) attenuation and structural return loss test is required
under M-17 Revisions “F” and “G.” This test is performed by sweeping each of the twenty-two (22) different
50 ohm coaxial cables over the frequency band for which their use is recommended. In the past, using the
older MIL-C-17 Revision “D” tests, it was very unusual to detect these narrow band, high attenuation spikes.
Coaxial cables that do not require “full band” swept frequency performance can be procured under separate part
numbers in an unswept version. The specification sheets for these unswept cables recommended they
not be used above 400 MHz. The end user or “OEM” must decide which cables will best suit the situation
and application.
MIL-C-17 QPL Listing and Cable Designations: M-17 Coaxial Cables must pass rigorous inspection and
qualification tests in order to obtain QPL listing, thus insuring consistent high-quality cables. Cables that are
manufactured to MIL-C-17 specification no longer carry the RG designation. Instead, they are marked with
M-17 designation. In the future, any new cable design will be designated by an M-17 part number. Only the
qualified military cables (QPL listed) are authorized to be marked with the military number after the proper
testing and requirements are met as specified in MIL-C-17 and applicable slash sheets. Radio frequency cables,
which are not qualified (QPL) to MIL-C-17 cannot be marked with the military specification part number (“M-17”)
and the word type either preceding or following the military part number. In addition to M-17 numbers, all
cables are marked with the manufacturer’s name and government identification number. Cables that are not
marked with all of this information are not qualified and there is no guarantee of their performance.
★★★★商品規格描述★★★★
MIL-C-17
ABBREVIATIONS
DIELECTRIC
FEP . . . . . . . . . . . . . . . . . .Fluorinated Ethylene Propylene (Solid)
PE . . . . . . . . . . . . . . . . . . .Polyethylene (Solid)
PIB . . . . . . . . . . . . . . . . . .Polyisobutylene, Type B, per MIL-C-17D
PS . . . . . . . . . . . . . . . . . . .Polystyrene
PTFE . . . . . . . . . . . . . . . .Polytetrafluoroethylene (Solid)
Rubber . . . . . . . . . . . . . . .per MIL-C-17
CONDUCTORS & BRAID MATERIALS
AL . . . . . . . . . . . . . . . . . . .Aluminum
BC . . . . . . . . . . . . . . . . . . .Bare copper
BCCS . . . . . . . . . . . . . . . .Bare copper covered steel
BerC . . . . . . . . . . . . . . . . .Beryllium-Copper Alloy
CCA . . . . . . . . . . . . . . . . .Copper covered aluminum
CCS . . . . . . . . . . . . . . . . .Copper covered steel
GS . . . . . . . . . . . . . . . . . .Galvanized steel
HR . . . . . . . . . . . . . . . . . .High resistance wire
NC . . . . . . . . . . . . . . . . . .Nickel coated copper
SC . . . . . . . . . . . . . . . . . . .Silver covered copper
SCBerC . . . . . . . . . . . . . .Silver covered Beryllium-Copper Alloy
SCCadBr . . . . . . . . . . . . .Silver covered cadmium bronze
SCCS . . . . . . . . . . . . . . . .Silver covered copper covered steel
SSC . . . . . . . . . . . . . . . . .Silver covered strip
TC . . . . . . . . . . . . . . . . . . .Tinned copper
TCCS . . . . . . . . . . . . . . . .Tinned copper covered steel
JACKET MATERIAL
CLP . . . . . . . . . . . . . . . . . .Cross-linked polyethylene
E-CTFE-X . . . . . . . . . . . . .Ethylene/Chlorotrifluoroethylene Copolymer
ETFE-X . . . . . . . . . . . . . . .Ethylene/Tetrafluoroethylene Copolymer
FEP-IX . . . . . . . . . . . . . . .Fluorinated Ethylene Propylene, Type IX, per MIL-C-17
FG Braid-V . . . . . . . . . . . .Fiberglass, impregnated, Type V, per MIL-C-17
HDPE . . . . . . . . . . . . . . . .High density polyethylene
PE-II . . . . . . . . . . . . . . . . .Clear polyethylene
PE-IIIA . . . . . . . . . . . . . . .High molecular weight, black polyethylene, Type IIIA, per MIL-C-17
PFA-XIII . . . . . . . . . . . . . .Perfluoroalkoxy, per MIL-C-17
PTFE . . . . . . . . . . . . . . . .Polytetrafluoroethylene, per MIL-C-17
PUR . . . . . . . . . . . . . . . . .Polyurethane, Black specific compounds
PVC-I . . . . . . . . . . . . . . . .Black polyvinyl chloride, contaminating, Type I, per MIL-C-17D
PVC-II . . . . . . . . . . . . . . . .Grey polyvinyl chloride, noncontaminating, Type II, per MIL-C-17D
PVC-IIA . . . . . . . . . . . . . . .Black polyvinyl chloride, noncontaminating, Type IIA, per MIL-C-17
Rubber . . . . . . . . . . . . . . .Per MIL-C-17
Sil/DAC-VI . . . . . . . . . . . .Dacron braid over silicon rubber, Type VI, per MIL-C-17
TPE . . . . . . . . . . . . . . . . . .Thermoplastic Elastomer
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