This is the simplest option. Hz resolution is useless for this purpose,
exhibits so many trailing zeroes that the preferences dialog overflows,
and overflows 32-bits values for satellite carrier frequencies.

This is also the default resolution for BDA. I see no need to copy the
"inconsistent" resolution if Linux-DVB (Hz for C/T, kHz for S).

For backward compatibility, frequencies beyond the radar bands are
divided by 1000. This corresponds to EHF and infrared in kHz.