WiNRADiO G33DDC HF Receiver
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During playback of the paused signal, the S-meter, the demodulator spectrum
and all demodulator controls will relate to the currently played back (buffered)
signal. However, the wideband and DDC spectrum displays, and the main
frequency read-out, will all relate to the currently received signal.
Spectrum Scopes
We have already touched on the spectrum scopes in some of the preceding
paragraphs, but there is much more to the WiNRADiO
Excalibur Pro
spectrum
scopes than just the ability to
“point-and-click” tune or drag the demodulator
filter passband.
The three spectrum scopes can be considered to be subsets of one another:
The
Wideband spectrum scope
is always 30 or 50 MHz wide (this selection
can be made using the
Frequency range
function located under the top bar
Options
menu).
A zoomed-in portion of the wideband spectrum is the
DCC spectrum
, whose
width can vary from 20 kHz to 4 MHz, selectable in 24 steps (this is selectable
using the
DDC BW
control). Finally, the
Demodulator spectrum
is a subset of
the DDC spectrum, making it possible to inspect the signal with the highest
resolution. The demodulator filter bandwidth (adjustable using the
DEM BW
control)
is the bandwidth of the last filter and the actual demodulated signal.
The demodulator spectrum width is the lesser value of 64 kHz and the DDC
bandwidth. The relationship between the selected DDC bandwidth and the
width of the demodulator spectrum is also shown in
Appendix E
–
Demodulator Spectrum Width
.
The grey shaded area in the wideband spectrum represents the DDC
bandwidth. The grey shaded areas in both the DDC and demodulator
spectrum both represent the currently selected demodulator filter bandwidth.
All three spectrum scopes use similar controls in their graphical user interface,
even though their functionality is different. Let’s have a look at the common
controls first, and leave the specific features of each spectrum scope till last.
