On Fri, Sep 28, 2012 at 3:28 PM, Josh Blum
<address@hidden> wrote:
On 09/27/2012 02:42 PM, LD Zhang wrote:
> Yes. I can understand the LFRX does not have any adjustable gain. But what
> comes out of the USRP source should be samples already digitized. Surely
> there is gain to be adjusted before the ADC. According what I see, it is
> from 0 to 6dB (in voltage?). I don't see how this can be inserted into the
> USRP source block.
>
You are correct. The N210 has a 6db digital gain. Attached is a GRC
flowgraph that loopsback TX and RX with Basic daguhterboards. You can
see the digital gain slider in action.
The gain parameter in the GRC block is a amalgamation of ADC and RF
frontend gain elements. The API also allows for individual control, but
this level of control is not available in the GRC gain parameter.