I've got a shielded tent in our office and I see one ambient element I don't have a good explanation for.

We see some ambient noise at 700MHz - 800MHz which I guess is cell-band noise.

But there is one persistent source of noise at 160MHz, that is also ambient and consistently present. Across 30MHz to 700MHz all other ambient noise is attenuated by the tent.

What could that be source of noise be, is it RF?

I'm actually thinking maybe it is noise from the Rigol spectrum analyzer? (Is 160MHz an FPGA?).