I'm able to tune HF, VHF, and UHF and above frequencies on my LimeSDR in receive - works really well and it REALLY helps to see the tuned frequency in the spectra while tuning. I'm currently listening to my local AM radio station on 1540 kHz and it sounds outstanding with a 10kHz BW. As well, I'm able to tune ANYWHERE in the HF band provided that I recognize that the sampling rate is set to 30 MHz and the NCO is tuned to the section of the band one wants to listen to, along with the Main tuning being set to 30.0 MHz. The HF SSB copy is really clear and perfect, too. Love those controls - you can set them everywhere.
I'm also able to transmit in all modes (AM/FM/USB/LSB) after you pointed out the antenna settings and gain control - - those were hidden until I pulled the menu down to see them and set them. But the audio quality is pretty sketchy, meaning in AM or FM it's pretty 'robotic' sounding and I've been trying all sorts of sampling rates, filtering and other functions but not improving on anything. I'm using a microphone off a gaming headset that normally sounds great and clear. I'm also using the PC resources (meaning that I'm using the HDA Intel PCH drivers). I've tried all sorts of audio driver and there no real difference. I'm not complaining - I think it's great that I can hear anything intelligible in AM, FM, and SSB (I haven't tried HF, just V/UHF right now). I even just brought it up as you had it at 435 MHz and setup a NBFM modulator and tried it - same thing...robotic sounding. Just wondering if you get normal speech from yours. My LimeSDR is on a 3.2GHz Intel PC with USB 3.0 and plenty of memory and disk space (not that disk space would matter for this, but for the record...). So it can keep up (I think)...but let me know.
Again, I know that transmit is experimental right now and I think what I'm seeing is just that. Just wanted to know if you've had better luck with voice audio in any of the modes. Also, I noticed that the CW generator is sending code and it sounds great over the air, but the characters seem different than what I remember...I'm pretty proficient with code. Is there a code setting other than speed? Please let me know that, too.
I'm pretty impressed with this SDRAngel application - It's VERY flexible and I'm real happy that the Lime CAN transmit, albeit with some work to do on the audio in transmit. I look forward to further updates of SDRAngle to improve on what's there in transmit. Someone that has an app (FooBar2000) that was made by @jocover that had perfect FM and AM audio. Possibly checking with him on some things he did or maybe you have it working by now...Just keep us advised of your efforts, Edouard.
Onward and upward..!
73 de Marty, KN0CK