This article details steps to perform when the "Antenna Short" alarm or the "Antenna Current High" alarm is seen in the Configuration Tool. The "Antenna Short" alarm is displayed in the Clock Tab and the "Antenna Current High" alarm is displayed in the GNSS/GPS Tab.
The Antenna Short/Antenna Current high alarm indicates that the antenna circuit current is high (typically over 100 mA). This is caused by a short in the antenna circuit, moisture ingress in the circuit, or if the connected antenna has a higher current drain specification.
Tekron clocks provide a 5V supply to the connected antenna. If the current is not being drawn from a clock, then it will give an antenna alarm/antenna fault. The following steps/tests should be performed to determine the location of the fault in the antenna installation, that is causing this alarm.
1. Disconnect the antenna from the clock (refer to #1 in image above), and check whether the "Antenna Short" alarm in the Clock Tab of the Configuration Tool disappears. If no antenna is connected to the clock, you should expect to see the "No Antenna" alarm in the Configuration Tool.
2. Keep the antenna disconnected from the clock. Use a multi-meter to measure the voltage at the antenna connector on the clock (refer to #1 in image above). This should measure 5V. If 5V is not measured, then this indicates an issue with the clock.
3. Re-connect the antenna cable at point #1. Then disconnect the antenna cable from the lightning arrestor at point #2 (if one has been installed), and measure the voltage at the end of the coaxial cable using a multi-meter. You should measure 5V if the clock and co-axial cable are operating correctly.
4. Re-connect the antenna cable at point #2. Then disconnect the antenna cable and lightning arrestor (if one has been installed) from the rooftop antenna at point #3, and use a multi-meter to measure the voltage at the lightning arrestor (at point #3). You should measure 5V if the lightning arrestor has been crimped properly and is operating correctly. If 5V is not measured, remove lightning arrestor from the antenna installation and follow this guide - How to test a lightning arrestor - to confirm the lightning arrestor is operating normally. If the tests fail, then the lightning arrestor should be replaced.
5. Re-connect the antenna cable and lightning arrestor at point #3. Then disconnect the antenna cable from the rooftop antenna from at point #4, and use a multi-meter to measure the voltage at the end of the co-axial cable. If this measures 5V, then this confirms the antenna installation is fine and that there may be an issue with the rooftop antenna.
If the Antenna Short alarm has not been cleared, or if any of the above tests have failed, please raise a support ticket and provide the results from the tests above.