 <hsc> can be set to 1/1000, 1/400, 1/200, 1/100, 1/40, or 1/20 of the FFT sample
rate.
 When the FFT mode is set to TRACe, FFT sample rate equals to screen sample rate,
that is, 100/horizontal timebase.
When the FFT mode is set to MEMory, FFT sample rate equals to memory sample
rate (:ACQuire:SRATe?).
 You can view the detailed information of the frequency spectrum by reducing the
horizontal scale.
:MATH:FFT:HSCale 500000 /*Set the horizontal scale of the FFT operation result to
500kHz*/
:MATH:FFT:HSCale? /*The query returns 5.000000e+05*/