Note (Rolf Mertig) :
I got rid of all FullSimplify and Simplify and changed some Solve to NSolve.
I took only 246 elements of freq (because one more gives a problem with d[1],. etc.)
freq = Take[freq, 246];
In[]:=
»
In[]:=
AbsoluteTime[]-$startTime
Out[]=
31.8378175