Satellite Radio User Manual

8 Micro Motion
®
Model 1700 and 2700 Transmitters
Installing the Transmitter
DC power requirements
Note: These requirements assume a single transmitter per cable. Connecting multiple transmitters to
a single cable should be avoided.
If you are using DC power, the following requirements apply:
• 18–100 VDC
• 6 watts typical, 11 watts maximum
• At startup, the transmitter power source must provide a minimum of 1.5 amps of short-term
current per transmitter.
• Length and conductor diameter of the power cable must be sized to provide 18 VDC minimum
at the power terminals, at a load current of 0.5 amps. To size the cable, refer to Table 2-1 and
use the following formula as a guideline:
Table 2-1 Typical power cable resistances at 68 °F (20 °C)
Gauge Resistance
(1)
(1) These values include the resistance of both high and low conductors in a cable.
14 AWG 0.0050 Ω/foot
16 AWG 0.0080 Ω/foot
18 AWG 0.0128 Ω/foot
20 AWG 0.0204 Ω/foot
2,5 mm
2
0,0136 Ω/meter
1,5 mm
2
0,0228 Ω/meter
1 mm
2
0,0340 Ω/meter
0,75 mm
2
0,0460 Ω/meter
0,5 mm
2
0,0680 Ω/meter
Example
The transmitter is mounted 350 feet from a DC power supply. If you want to use 16 AWG
cable, calculate the required voltage at the DC power supply as follows:
MinimumSupplyVoltage 18V CableResistance CableLength× 0.5 A×()+=
MinimumSupplyVoltage 18V 0.0080 ohms/ft 350 ft× 0.5A×()+=
MinimumSupplyVoltage 19.4V=
MinimumSupplyVoltage 18V CableResistance CableLength× 0.5A×()+=