Base Station Setup—Amplifier Option

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Amplifier Assembly

CAUTION: Install and operate the amplifier safely. Read and follow PREVENT ELECTRICAL SHOCK AND FIRES and AVOID EXPOSURE TO HIGH RADIO FREQUENCY FIELDS in the SAFETY section.

The primary reason for 450 MHz RTK is to provide a more robust RTK data link. Signal strength is the dominant factor in the link reliability and range. For areas where there are trees and other foliage, John Deere offers an optional in-line amplifier.

The PF81443 amplifier is a UHF RF power amplifier intended for use in 450 MHz RTK system. It is not intended to be used with 900 MHz RTK or any other applications. The amplifier can deliver RF power from 0 to 50 W proportional to the 0 to 2 W input from 450 MHz RTK Radio. It covers a frequency range from 450 MHz to 470 MHz. This higher signal strength provides greater range from the base and increased coverage in areas with dense foliage and trees.

This amplifier is inserted between the radio and the base antenna. The amplifier has been designed to function outdoors attached to its mounting plate with sun shade. Mount the amplifier in an area where air can freely circulate around it. If possible, mount in a location shaded from direct sunlight.

Operation of the amplifier inside an enclosure is not recommended. Poor ventilation within the box can cause the amplifier to overheat. While this would not permanently damage the amplifier, it would cause it to stop amplification. The output signal would no longer be strong enough for the vehicles in the field to receive.

450 MHz Amplifier Specifications

Model Number	PF81443
Frequency Range	450-470 MHz
Input Power	0-2 W
Output Power	0-50 W
Nominal Passband Gain	14 dB
20 dB Nominal Passband	250 MHz
Current During Transmission	8 amp
Nominal Voltage	13.8 V DC
Internal fuse	15 amp
In/Out Impedance	50 ohm
Operating Voltage	11-15 V
Max Duty Cycle	100%
Operating Temperature	-30 to 60° C
In RF Connector	Female TNC
Out RF Connectors	Female N-Type
Power Connector	Amphenol (EcoMate C016 20D003 110 12)

The manufacturer’s rated output power of this equipment is for single carrier operation.

There are 3 connections located at the bottom of the power amplifier:

1. 12 VDC power input
2. RF input via TNC connector
3. RF output via N-Type connector

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Amplifier Connection Ports

The connectors should only be finger-tight. Using tools can over tighten and damage the RF and power connectors.

A 13.8 V power supply capable of providing a constant 10 amp to the amplifier is required. Amplifier operation with insufficient voltage can lead to higher amplifier operating temperatures. Insufficient current can cause the amplifier to not amplify or only partially amplify the RF signal. These conditions result in incomplete or no RTK transmissions being received by the vehicle.

IMPORTANT: Make sure the antenna and coax are attached before the amplifier module is powered ON or damage to the amplifier could occur. Do not remove the coax or antenna while the amplifier is powered ON. Avoid water intrusion by keeping the connections attached whenever possible.

Make sure the power connector is attached and unpowered when handling the RF IN and RF OUT connectors. The ground provided by the power connector protects the amplifier against possible electrostatic discharge.