John Deere 002850.05 – GR6: Reflected Antenna Power too High

The StarFire receiver has detected a high Standing Wave Ratio (SWR) from the RTK radio antenna. This indicates an impedance mismatch or a fault in the antenna system, causing excessive radio frequency power to be reflected back to the transceiver instead of being broadcast. This condition can result in reduced transmission and reception performance, leading to poor GPS accuracy and communication issues.

• StarFire 3000
• StarFire 6000
• Tractors
• Combines
• Self-propelled forage harvesters

1. 1

   Visually inspect the RTK radio antenna, cabling, and connections for physical damage, corrosion, or loose fittings. Ensure the antenna is mounted vertically.

2. 2

   Verify that all connections in the antenna system are tight and secure from the antenna to the receiver.

3. 3

   Check the coaxial cable for pinches, cuts, or sharp bends that could damage the internal wiring.

4. 4

   Ensure the antenna has a proper ground plane, as an inadequate ground can lead to high SWR readings.

5. 5

   Confirm that the antenna is not obstructed by other vehicle components or metallic surfaces. There should be a minimum clearance of 15 feet (4.5 meters) from other antennas.

1. 1

   Clear fault code

   After performing any corrective actions, clear the diagnostic trouble code from the control unit's memory and perform a functional check to see if the code reappears.

2. 2

   Swap antenna

   If a known good antenna is available, swap it with the suspect antenna to determine if the fault lies with the antenna itself.

3. 3

   Test coaxial cable

   Use a multimeter to test the coaxial cable for continuity and to ensure there are no shorts between the center conductor and the shield.

4. 4

   Replace faulty components

   If the fault is isolated to a specific component, replace it with a new, genuine John Deere part. This may include the antenna, the coaxial cable, or the radio module within the StarFire receiver.