Re: [Discuss-gnuradio] Unable to tune Tx or Rx with XCVR2450 on USRP2

[Josh Blum]

It could be failing to lock. You may want to watch the debug port on the 
usrp2. If the lock detect is failing, it will print out on the serial 
console. attach a 3.3v level serial port

On 01/28/2010 10:09 PM, Ian Holland wrote:
> Hi Josh
>
> > The xcvr has a high band and a low band, which means there is a gap in
> > the tunable frequency range for the xcvr. Therefore, the
> > "auto-calculated mid-point frequency" is an invalid frequency for the
> > xcvr. Pick a frequency in the high band or low band range:
>
> > #define LB_FREQ_MIN U2_DOUBLE_TO_FXPT_FREQ(2.3e9)
> > #define LB_FREQ_MAX U2_DOUBLE_TO_FXPT_FREQ(2.6e9)
> > #define HB_FREQ_MIN U2_DOUBLE_TO_FXPT_FREQ(4.8e9)
> > #define HB_FREQ_MAX U2_DOUBLE_TO_FXPT_FREQ(6.1e9)
>
> Thanks - I will keep that in mind when using usrp_siggen.py in future.
>
> However, I have tried 2.4G with the source code from my original post
> (relevant code snippet for Tx tuning just below this paragraph, for
> which successTx is 0 and all frequency properties in TxTuneResult are
> 0), and also with usrp2_fft.py -f 2.4G, after burning the latest images.
> I still face the same problem that neither the Tx nor the Rx will tune.
>
> /* try tuning Tx to a test frequency */
> double Fc = 2400000000.0;
> usrp2::tune_result TxTuneResult;
> bool successTx = device->set_tx_center_freq(Fc,&TxTuneResult);