User’s Manual
6.1.5 Technical Details on GPS Antennas and Cables
Antenna Cable
Length and Loss Considerations
Standard Antenna Cable
The standard antenna cable assembly included with
using a 15-meters (50-foot) length of RG
connector and BNC male connector. Optional lengths of RG
er runs; see Table 6.1, Cable Data and Accessory Information.
Effects of Cable Parameters
To receive GPS signals and properly operate the
ble are important. Due to their effect on specific parameters described in the following paragraphs,
any changes to the length and/or type of antenna cable should be made carefully. Damaged cables
may also affect performance.
Cable Delay
The velocity factor and the physical length of the cable determine cable delay. User has to enter d
lay value according to antenna cable length.
For cable options, the delay is tabulated below. The formula for calculating
cable delay is:
Where:
T = Cable delay, in nanoseconds;
λ
= Cable length, in meters;
C = Speed of light (3 _ 108 meters per second);
Kv = Nominal velocity of propagation (0.85).
One nanosecond is added to the calculated value to account for the length and velocity factor of the
short connecting cable inside of the
Attenuation
Attenuation depends upon the cable length, and the loss per unit length. The total attenuation must
be limited to 30 dB (maximum) at the GPS L1 frequency of 1575.42 MHz
DC Resistance
The cross-sectional area and length of the conductors in the cable determine the dc resistance.
power to the RF preamplifier in the antenna is supplied via the antenna cable, excessive dc resi
tance will degrade performance.
antenna cable should be made carefully. Damaged cables may also affect performance.
Doc Ref. No:
Technical Details on GPS Antennas and Cables
Length and Loss Considerations
The standard antenna cable assembly included with GPS TIME SYNC UNIT MC-1
foot) length of RG-6 type low-loss coaxial cable, terminated with male Type N
tor and BNC male connector. Optional lengths of RG-6 coax are separately available for lon
, Cable Data and Accessory Information.
To receive GPS signals and properly operate the GPS Time Sync Unit, the type and length of the c
ble are important. Due to their effect on specific parameters described in the following paragraphs,
any changes to the length and/or type of antenna cable should be made carefully. Damaged cables
The velocity factor and the physical length of the cable determine cable delay. User has to enter d
lay value according to antenna cable length.
For cable options, the delay is tabulated below. The formula for calculating
T = Cable delay, in nanoseconds;
C = Speed of light (3 _ 108 meters per second);
Kv = Nominal velocity of propagation (0.85).
One nanosecond is added to the calculated value to account for the length and velocity factor of the
short connecting cable inside of the GPS Time Sync Unit.
Attenuation depends upon the cable length, and the loss per unit length. The total attenuation must
dB (maximum) at the GPS L1 frequency of 1575.42 MHz
sectional area and length of the conductors in the cable determine the dc resistance.
power to the RF preamplifier in the antenna is supplied via the antenna cable, excessive dc resi
tance will degrade performance. Because of the above factors, changes to the length and/or type of
ade carefully. Damaged cables may also affect performance.
Model: MC-1-DE
Doc Ref. No:-m05dom102
Issue No:-00
Page 24 of 76
1-DE is constructed
loss coaxial cable, terminated with male Type N
6 coax are separately available for long-
ype and length of the ca-
ble are important. Due to their effect on specific parameters described in the following paragraphs,
any changes to the length and/or type of antenna cable should be made carefully. Damaged cables
The velocity factor and the physical length of the cable determine cable delay. User has to enter de-
One nanosecond is added to the calculated value to account for the length and velocity factor of the
Attenuation depends upon the cable length, and the loss per unit length. The total attenuation must
sectional area and length of the conductors in the cable determine the dc resistance. Since
power to the RF preamplifier in the antenna is supplied via the antenna cable, excessive dc resis-
ctors, changes to the length and/or type of
ade carefully. Damaged cables may also affect performance.