Re: [Discuss-gnuradio] USRP2 TX Gain

[Eric Blossom]

On Sun, Dec 21, 2008 at 09:09:53AM -0800, Yabo Li wrote:
> Hi Eric,
> 
> Thanks. So the USRP2 can not adjust hardware gain, right? But I found
> that the "set_tx_gain" is provided in the lib. Doesn't it work or not?
> 
> Yabo


    /*!
     * Set transmitter gain
     */
    bool set_tx_gain(double gain);

    //! return minimum Tx gain 
    double tx_gain_min();

    //! return maximum Tx gain 
    double tx_gain_max();

    //! return Tx gain db_per_step
    double tx_gain_db_per_step();


It may be possible for a daughterboard to provide transmit gain
adjustment.  IIRC, at this time none of them do.  In any event,
tx_gain_min() and tx_gain_max() will return sensible answers.
If tx_gain_min() and tx_gain_max() return the same value, then
there's only a single valid value that you can pass to set_tx_gain.

Eric