We are using a LibreSDR purchased from AliExpress for satellite communication as part of our university radio club project. However, we are experiencing significant issues related to the power output and TX switching behavior with the prebuilt firmware.
Observations
Low Power Output:
When transmitting in CW mode, the measured power output is only -7 dB to -4 dB, which is significantly lower than the expected 7 dB. This measurement was taken using a calibrated spectrum analyzer. Measures:
Via LAN: @2.4GHz = -5dBm
Via USB: @2.4GHz = -7dbm
Via LAN: @145MHz = -3dBm
Via USB: @145MHz = -5dBm
TX Switching Problem:
The device does not seem to properly switch between TX0 and TX1 when attempting to change the output channel. Regardless of the settings used in software, the device always transmits from TX1.
Testing and Setup
We have used prebuilt firmware without any modifications.
The same issue with release v0.3.8 (overclock_cpu900_ddr650.tar.gz)
Tried various setups with different cables, stabilized power sources, and configurations.
Request
We suspect there may be a problem with the firmware, especially regarding the TX switching and power output. Could you please provide insights or advice on how to address these issues, or suggest modifications to the firmware to resolve this?
Device: LibreSDR (https://vi.aliexpress.com/item/1005005165734650.html) Firmware Version: Prebuilt firmware from OpenSourceSDRLab
Software Used: SDRconsole via LAN/USB
Description
We are using a LibreSDR purchased from AliExpress for satellite communication as part of our university radio club project. However, we are experiencing significant issues related to the power output and TX switching behavior with the prebuilt firmware.
Observations
Low Power Output:
When transmitting in CW mode, the measured power output is only -7 dB to -4 dB, which is significantly lower than the expected 7 dB. This measurement was taken using a calibrated spectrum analyzer.
Measures: Via LAN: @2.4GHz = -5dBm
Via USB: @2.4GHz = -7dbm Via LAN: @145MHz = -3dBm Via USB: @145MHz = -5dBm
TX Switching Problem:
The device does not seem to properly switch between TX0 and TX1 when attempting to change the output channel. Regardless of the settings used in software, the device always transmits from TX1.
Testing and Setup
Request
We suspect there may be a problem with the firmware, especially regarding the TX switching and power output. Could you please provide insights or advice on how to address these issues, or suggest modifications to the firmware to resolve this?