This note concerns support of the LimeRFE frontend in qradiolink.
This note applies both to receive and transmit RF paths, including duplex mode (connectors J3/J4 used simultaneously).
Up to and including version 0.8.6-2, LimeRFE automatic band tuning was limited to IARU region 1 amateur radio bands.
The 220 MHz and 900 MHz bands were not supported at all.
The 144 MHz and 440 MHz bands were only partly supported for IARU region 2, as these bands cover more spectrum there.
The automatic tuning as implemented in version 0.8.6-2 would choose the WIDEBAND-1000 and WIDEBAND-4000 RF paths for frequencies outside IARU region 1 bands, and these RF paths do not have any filtering on input and output.
The next version of qradiolink will correct this issue and enable support for all amateur radio bands that the LimeRFE provides, while extending the frequency range where amateur radio receive and transmit paths are enabled. This will allow amateur radio operators in IARU region 2 to use the full extent of their bands.
The range of frequencies where these ham bands are enabled was set using the gain measurements for RX paths in the LimeRFE reference documentation available at and may be slightly altered in the future if necessary.
Do note that the "TX Limits" option will still restrict (if enabled) tuning the transmitter outside IARU region 1 bands. To use the transmitter in IARU region 2 or other IARU zones you will still need to disable this option in the settings. For ease of operation, this setting was moved to the first settings page.
As there is no release yet with the new features, you will need to compile the software from source to take advantage of the new code.
//Adrian
