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Applications for PLC with high attenuation may require more transmitter power than the standard 10/20 watts. The LPA50 and LPA100 are available for these applications. They are typically applied where line attenuation is a serious problem as in extremely long lines (150 miles (242 km) or more) or where underground cable is used for all or part of the line. Combining cable with overhead lines creates an impedance mismatch between the 20 to 60 ohm cable and the 150 to 300 ohm overhead line. This mismatch can cause a portion of the carrier signal to be reflected back to the transmit end, attenuating the signal significantly.<BR><BR>The LPA50 and LPA100 are linear amplifiers which allow several frequencies to be passed through without intermodulation or custom filters. No adjustments or settings are required for any transmit frequency. By combining two or more frequencies at the lower levels, hybrids can be eliminated; thus increasing the resultant power output. Up to three frequencies can be combined using the LPA100 with each frequency having more than 10 watts of power going into the line tuner. That is: 100 watts divided by the square of the number of frequencies.
Hardware
The LPA50 is packaged in the same 3 RU chassis as the TC-10B and TCF-10B. The same power supply and power amplifier modules are utilized. The LPA100 is contained in two 3 RU chassis. Four 12.5 watt power amplifier modules are combined to form one LPA50, while the LPA100 consists of eight 12.5 watt modules.
Connections
- Terminal blocks for the battery input and alarms
- UHF/BNC connectors for the RF inputs and outputs
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