Cables Coaxiales
Propiedades Físicas
Cable
Inner Conductor
Dielectric
Shield
Jacket
Overall Diameter
RG58C
0.90mm 19:TC
PE
1:TC
PVC
4.95mm
RG213
2.26mm 7:BC
PE
1:BC
PVC
10.3mm
RG214
2.26mm 1:SC
PE
2:SC
PVC
10.8mm
RG223
0.89mm 1:SC
PE
2:SC
PVC
5.36mm
RG402/UT141
0.91mm 1:SCCS
PTFE
1:TCT
none
3.58mm
Belden 9913
2.59mm 1:BC
Semisolid PE
2:AF,TC
PVC
10.4mm
Belden 9913F7
2.59mm 7:BC
PE Foam
2:AF,TC
Belflex PVC
10.3mm
LMR400
2.77mm 1:CCA
PE Foam
2:AF,TC
PE
10.3mm
LMR400UF
2.77mm n:BC
PE Foam
2:AF,TC
TE
10.3mm
FSJ4-50B
21:BC
PE Foam
1:CCT
PE
13.2mm
LDF4-50A
4.8mm 1:CCA
PE Foam
1:CCT
PE
16.3mm
LDF5-50A
9.1mm 1:BCT
PE Foam
1:CCT
PE
27.5mm
- AF: Aluminium foil
- BC: Bare Copper
- BCT: Bare copper tube
- CCA: Copper clad aluminium
- CCT: Corrugated copper tube
- PE: Polyethylene
- PTFE: Teflon
- PVC: Polyvinylchloride
- SC: Silver coated copper
- SCCS: Silver covered copper clad steel
- TC: Tinned copper
- TCT: Tinned copper tube
- TE: Thermoplastic elastomer
Propiedades Eléctricas
The attenuation properties of coaxial cables are given at frequencies like 100MHz, 200MHz, 400MHz in various places such as manufacturers' catalogues, amateur radio handbooks, and personal web pages, and also in various units. It is not easy to reconcile all these values with each other, but the following table represents what I believe to be a reasonable approximation to the truth. The velocity factors of PE Foam cables may vary slightly around the nominal value.
Cable
Impedance
Velocity Factor
Attenuation 144MHz
Attenuation 432MHz
Attenuation 1296MHz
RG58C
50 ohm
0.659
19dB/100m
33dB/100m
63dB/100m
RG213
50 ohm
0.659
8.4dB/100m
15.6dB/100m
30dB/100m
RG214
50 ohm
0.659
8.4dB/100m
15.6dB/100m
30dB/100m
RG223
50 ohm
0.659
17dB/100m
29dB/100m
56dB/100m
RG402/UT141
50 ohm
0.694
14.4dB/100m
25dB/100m
43dB/100m
Belden 9913
50 ohm
0.84
5.1dB/100m
9.2dB/100m
17dB/100m
Belden 9913F7
50 ohm
0.83
5.7dB/100m
9.8dB/100m
18dB/100m
LMR400
50 ohm
0.85
4.8dB/100m
8.7dB/100m
15.5dB/100m
LMR400UF
50 ohm
0.85
5.5dB/100m
10.0dB/100m
18.6dB/100m
FSJ4-50B
50 ohm
0.80
4.2dB/100m
7.5dB/100m
13.5dB/100m
LDF4-50A
50 ohm
0.88
2.8dB/100m
5.0dB/100m
9.0dB/100m
LDF5-50A
50 ohm
0.89
1.5dB/100m
2.7dB/100m
5.0dB/100m
Power handling depends more on temperature rise due to cable loss than on insulation voltage.
- Thus it varies with frequency in much the same way as cable loss, and of course depends also on the melting point of the insulation (usually polyethylene or teflon). The figures given relate to "flat" lines on which the SWR is 1.0. The presence of a standing wave will cause points where the current is higher than the average (and other points where it is lower). Power handling figures should therefore be derated when a significant standing wave is present, as in baluns.
Cable
Power 144MHz
Power 432MHz
Power 1296MHz
RG58C
240W
100W
50W
RG213
800W
430W
200W
RG214
650W
340W
175W
RG223
400W
200W
100W
RG402/UT141
2000W
1000W
550W
Belden 9913
1065W
603W
342W
Belden 9913F7
935W
533W
304W
LMR400
1500W
830W
470W
LMR400UF
1000W
550W
310W
FSJ4-50B
2490W
1380W
770W
LDF4-50A
2750W
1530W
860W
LDF5-50A
6040W
3320W
1810W
Perdidas por Atenuación
Debemos tener en cuenta:
- Cuanto más largo sea el cable coaxial, mayor será la pérdida de señal
- La calidad del cable afecta a la pérdida de señal / metro. Podríamos decir que:
cable de menor pérdida = cable más grueso y rígido = cable más caro
No existe longitud máxima para el cable coaxial, pero a mayor longitud, mayor pérdida.
A continuación, una pequeña tabla que muestra la relación entre modelos de cable LMR y RG y pérdida de señal / metro longitudinal a una frecuencia de 2.4GHz:
Cable
Pérdida en dB/100m
RG-58
105.6
RG-8X
75.8
RG-213
49.9
LMR-100
130.0
LMR-195
62.0
LMR-200
54.2
LMR-240
41.5
LMR-300
34.0
LMR-400
21.7
LMR-500
18.0
LMR-600
14.2
LMR-900
9.58
LMR-1200
7.27
LMR-1700
5.51
Belden 9913
25.3
LDF4 3/8"
19.4
LDF4 1/2"
12.8
LDF5 7/8"
7.5
