I did a pen of coturnix and bobs for this cross around seven years ago. I had three male northerns in a pen with around 10 coturnix hens.. never could get an egg to hatch. But I never tried very hard with it. Best of luck to you!
And this was more or less just a place of holding for the birds, which just so happened to be 3.10 or so at the time... didn't really actively try to get bb, and I am not sure what I would have done with any babies I would have had to hatch!