SDX-Compact: No corrections over UHF radio

The system shows no RTK corrections, and a UHF radio is set up. Work through the checks in order; the first one that fails is the likely cause.

Check the software version

For 900 MHz Leica base stations the system needs SDX-Framework 2.12.0 or newer. Open System logs and read the version in the system_online entry. If the version is older, update the system first.

Check the base station and the channel

For a 400 MHz base station, check that Frequency, Channel spacing, Communication protocol, and FEC match the base station.

Check that the base station is a Leica and that it transmits on 900 MHz.
Go to Project Settings > Systems and open the settings of the system.
On the Settings tab, in Default UHF configuration, check that Frequency band is 900 MHz Freewave and that Base station is Leica.
Check that Channel is the channel that is set on the base station.

Check that the base station transmits

Confirm on the base station itself that it is sending corrections. A system cannot receive what is not transmitted. The radio does not accept CMR corrections.

Read the system logs

Open System logs and look for these entries. The examples are from a 400 MHz system:

If radio bytes per minute entries never appear, no data reaches the GNSS receiver. Go back through the checks above, then check the antenna and the cable.

Log entry	What it tells you
config uhf	Which UHF configuration was applied: frequency, channel spacing, modulation protocol, and FEC.
radio bytes per minute	Radio traffic in kilobits (`radio_kbits`) and kilobits per second (`radio_kbits_per_second`). It appears only while there is traffic.

System logs with the config uhf entry selected; its details list Frequency, Channel spacing, modulation_protocol and FEC

System logs with the radio bytes per minute entry selected; its details list radio_kbits and radio_kbits_per_second

Check the antenna and the cable

Check that the radio antenna is mounted and the SMA connector is tight.
Keep the radio antenna at least 1 m (3.3 ft) from other radio antennas.
Check that no metal part blocks the antenna.

If corrections are still missing

Contact Sodex Support with the system and the time of the problem. See Install the SDX-Compact Hardware for the contact details.