Spectracom Corporation
8194B, 8195B, 8197B
GPS Ageless Master Oscillator Instruction Manual
5-7
5.3.2 Design of Distribution Networks
This section provides guidelines for using the Option 03 distribution outputs. In planning
a system installation follow the guidelines listed below:
1. A maximum of 25 Line Tap loads may be driven from one base station. More than
25 loads are not permitted due to power supply limitations and impedance matching.
Table 5-1, LINE TAP LOADS, lists the equivalent number of loads and current each
distribution device consumes. The receiver may provide up to 1.2 Amps total to the
distribution network.
DEVICE LOADS
CURRENT
(mA)
8140T All Versions
1
45
8140TA
1
45
8140VT
Standard
3
150
8140VT w/Opt 45
5
250
8140VT w/Opt 48
4
200
8140VT w/Opt 62
4
200
8140MT
3
150
Table 5-1 Line Tap Loads
If more than 25 Line Tap loads are required you may:
Add a Model 8140 Frequency Distribution Amplifier. The Model 8140 contains an
internal power supply and will feed an additional 25 Line Tap loads. A Line Tap is
required (typically 10 MHz) to provide the input frequency source to the Model 8140.
This “Daisy Chaining” may be continued indefinitely.
2. Voltage drops and signal attenuation limit the longest trunk line using RG-58 cable
to1500 feet (457 m).
Figure 5-1, LINE TAP NUMBER AND DISTANCE CHART, is used to calculate the
number of Line Tap loads that may be used at various distances from the base station.
For example, if 25 Line Taps are used, their average distance from the amplifier is
limited to 750 feet (228 m), using RG-58. Up to 12 Line Taps may be placed at 1500
feet (457 m) on any one trunk line.
If longer runs are required, you may:
A. Locate the unit in the geographical center of the installation, running
distribution lines in both directions and achieving a coverage of 3000 linear
feet (914 m).
