[Discuss-gnuradio] Questions regarding interpolator and usrp.sink_c configuration

[Milo Wong]

Hi All,

Here I have a couple of questions during my project:

1, I am receiving "uU"(usrp underrun) when I am transmitting, it seems 
that the data rate I feed to DAC is less than 128MS/s? I've already set 
the maximum interpolation rate at 512. What's the problem might be? I 
guess the input data rate of usrp.sink_c is too low. If so, is there any 
block plays the function of interpolator? If I have errors in my 
reasoning or consumption, please point me out.

2. Since the block : usrp.sink_c doesn't have the parameter of Tx 
frequency in its parameter list. Is that means I have to define a 
function like set_freq() and call it? Is there anyway I could set a 
fixed tx frequency in python without input that from the command line 
option. I only have one daughterboard RFX2400.


Any suggestions and advice will be appreciated.

Thanks,

Milo