slicerwizard
Member
No. The green trace is the zoomed RF spectrum display. Nothing "audio level" about it.
From FMP.txt:
" show/hide zoomed spectrum
press Z to toggle display on/off
zoomed spectrum shows tuned signal detail and centering in passband
higher FFT sizes (set in FMP.cfg) show finer detail
lighter background shows RF filter passband and transition bands
tuned signals should be centered in passband
majority of signal should be in passband
signal edges can be in transition bands"
The white trace (U) is the full unzoomed RF spectrum that FMPx can see and typically spans several MHz.
The thin white vertical line (V), typically in the left half of the spectrum display, marks the portion of the RF spectrum that FMPx is "tuned" to and is demodulating into audio.
That same tuned RF spectrum is displayed in the center of the FMPx window, zoomed in, using a green color. The lighter background (P) at the center marks the RF filter passband. The darker background bands (T) on either side mark the RF filter transition bands. The zoomed green RF signal (Z) that's in those three bands is what's getting demodulated. Anything outside those bands ain't getting demodulated. Most of the target signal should fit in the passband and transition bands. If the signal is smaller than the filter bands, select a smaller filter, 'cause you're needlessly pulling in extra noise. The edges (E) of a signal, where the green trace is more than 20 dB down from the peak in the center of the signal, don't contribute much/anything to DSD+'s decoding efforts, so those signal edges can be beyond the filter transition bands.
The zoomed RF display aids in tuning / centering / filter bandwidth selection and in signal identification (an NXDN48 signal looks much different than a DMR signal; most analog signals, with their varying modulation, look much different than digital signals). None of these details can be readily seen in the unzoomed white RF spectrum display.
