Re: LimeSDR USB parameter help

[Amr Bekhit]

> * should it work for GR 3.8?
> Right now the Frequency sink just shows random noise.
I have worked with the LimeSDR on 3.7, but not on 3.8. According to
github, work is still in progress to port LimeSuite to 3.8
(https://github.com/myriadrf/gr-limesdr/issues/44)

> On the "Properties: LimeSDR Source (RX)" screen:
>
> Channel A Properties:
>    NCO frequency
The NCO is used a secondary digital mixer to allow you to tune down to
below the 30Mhz limit on the LMS7000. Set it to 0 to allow the driver
to automatically calculate it for you.

>    Calibration bandwidth
This should be set to at least the sampling rate. It sets the
bandwidth across which the LimeSDR calibrates out the LO frequency
bleeding into the received signal, if I'm not mistaken.

>    LNA path
This sets the RF input port that is connected to the LMS7000 chip. The
LimeSDR has 3 RF inputs per input channel: Low, High and Wideband.

>    Analog filter bandwidth
This is a programmable analogue filter on the RF input. Like the
calibration bandwidth, you can set this to 0 to let the driver
calculate it for you.

>    Digital filter bandwidth
This is a digital filter present after the NCO digital mixer. Again, set to 0.

>    Gain (dB)
RF input gain - goes from 0-60dB. Probably start with something like
30dB and work from there.

>
> * is the output signal centered at the RF frequency, or is there an
> offset?
The output signal should be centred around the RF frequency.

>
> on the board there are RX1_L, RX_H, RX_W, RX2_L, RX2_H, RX2_W connectors
> INFO: device_handler::set_antenna(): CH0 antenna set [RX]: LNAL.
> * which connector corresponds to LNAL? Is it RX1_L?

If this is the Channel A tab, then LNAL refers to RX1_L. If it's the
Channel B tab then LNAL refers to RX2_L.