In GQRX there is a tab on the right side for demod and antenna selection. There is also a pull-down list and you select the antenna port that you’ve modifed for HF use (RX1_W or RX1_L) then adjust the LNA, PIA, and TIA gains as appropriate to obtain best signal strength.
If you have no antenna selections, then you may have an issue with GQRX not seeing the Lime. Hopefully you’ve done the ‘driver=lime,soapy=0’ entry on the first line (Device String) of the form for the board you’re using (Lime). In the upper right-hand corner there’s an icon that looks like a circuit board. Click on that and then ensure you have ‘driver=lime,soapy=0’ in the first space and also ensure that the Bandwidth entry is (and type it exactly like this) 100000000
Also, look at this thread for settings for GQRX, too -----> LimeSDR with Gqrx is working!
Let us know how you’re doing if you still cannot start GQRX.
73 de Marty, KN0CK