The Top Controls include the VFO boxes each of whose digits can be individually changed up or down with a mouse wheel. The group to the
right holds the meter, whose appearance and dynamics can be changed with the pair of dropdowns on the right hand side. The meter reads the
true RMS power in dBm of the current signal within the passband within 0.1dB.
The two controls to the left of the meter are, at the top, the mouse wheel tuning step size
and under that the number of fft bins of the display.
Each of these is remembered per mode.
Useful tuning NaP3 step selections might be 5kHz for AM, 12.5kHz for FM, 100Hz for LSB/USB and
5Hz for RTTY/PSK. This does not set
the rig tuning rate - but tuning via NaP3 makes the rig follow.
The higher the FFT setting, the greater the potential resolution of the display Typical settings
might be 4096 for wide span AM or LSB/USB
but 65536 for RTTY or PSK. 16384 is good for most use, Higher fft numbers are most use at narrow spans - but the response will become
slower at higher values, so a reduction in spectrum averaging time may be useful.
Calibration of the display level will be retained for different FFT bin numbers, but the higher the number the more the displayed noise floor
will drop - even showing signals you cannot hear, including stuff picked up from the computer and cabling. Remember: NaP3 only displays
what it is fed.