Re: [Discuss-gnuradio] Help on GRC to transmit at a specific frequency and width

[Eric Blossom]

On Fri, Aug 28, 2009 at 09:00:07AM -0700, Josh Blum wrote:
> The sample rate of the signal source is 1M. The sample rate of the usrp2  
> is 100M/64. Your rates disagree.
>
> -Josh
>
> dennis wrote:
>> Hi @ all
>>
>> Sorry, this stuff is new for me and therfore sorry for a possible 
>> stupid question ;-) . I play a little with GRC and want to transmit 
>> e.g. a cosine-wave at a specific frequency e.g. at 900MHz and width, 
>> say 2MHz. But my problem are as following:
>>
>> If i add only 2 blocks, i got nice constant transmission  but the width 
>> are too large, say more than +- 30 Mhz
>>  __________             ______________
>> |   signal   |           |                      |           source:  
>> sample_rate: 1M, waveform:cosine, Frequency: 1k, Amplitude: 100
>> |  source   |--------->|  usrp2 sink   |          usrp2 sink:  
>> interpolation: 64, Frequency: 900 MHz, Gain: 0
>> |__________|           |______________|

The USRP2 expects its input to be be between 0 and 1.0.  Try using
Amplitude = 0.1

Eric