Markus;
Seems as you get lower  there is some junk that I don't know what creates it.  I am surprised so many sigs and artifacts exist on these freqs.  But can't go down near 73.6 of course with that signal blasting in most nights at 30 over nine.  I have allot of signal  going west that would punch through allot of the junk as west coast is lot closer than T/A stations. 
I'll try 74.612 at Hartmut and Victor's request but if no good shoot me an e mail and can go up or down several hz if we have to.  Otherwise if 74.612 vicinity  is not the best we can try your choice tomorrow if you like.
I was wondering what it's like in Europe down at low end [68-70]?  Wonder if it might be harder to get sigs out as freq getting closer to VLF!  If it's clear I would think it might be better even though lower by several percent.  However, I will have to add "L" and retune things.  Might take too much time and just stay around 74.612 for tonight.
Of course, 74.323.431 going to need to change dial freq.  That would be hard in middle of evening's transmissions-really need better propagation to get my one watt sigs into Europe.  Cold here [8-10 F] for tonight which will add to conductivity and help with better start towards N Atlantic.
Bob