[CIG-SEISMO] Ricker wavelet, frequency!!!

[GulaAK at ipgg.sbras.ru]

Hi,

I'm post-graduated sudent (PhD sudent) of Trofimuk Institute of Petroleum Geology and Geophysics SB RAS.
I use SPECFEM3D for seismic problems, local scales. 

I  have redefined time source function to Ricker wavelet in compute_add_source_elastic.f90 
as elastic domain & sources for using it with pure compression, i.e. I use it with CMTSOLUTION 
with little scale of the model, which has minimal mesh step 30 m for forward simulation
I want to use seismic frequency (25-50 Hz), so  

 f0 = hdur(isource) !! using hdur as a FREQUENCY just to avoid changing CMTSOLUTION file format

However I could not set hdur more then 1, when I set more then 1 it write anything in plot_source_time_function.txt file.
How I understand solver makes seismograms by delta function, afterwards it convolves them with my source function. 
As a result I have seismograms with a noise, which is generated in the simulation by using a step source time function.
I set hdur by 0.5 Hz (for checking) and had result, which I have filtered afterwards by law-pass filter and  have had a clear result.
When I determined my time source function with desired frequency in comp_source_time_function.f90, I also had result with a noise, 
but in this case I couldn't filter it without missing of the useful singnal.

How I can set hdur more then 1? Or nevertheless the best way is the running the solver with half duration set to zero
and the convolving the resulting synthetic seismograms in post-processing after the run?