Below is shown a SpanaFall display split between Spanadapter and Waterfall.
These, plus Scope, Spectrum (audio) and Histogram of
the received signal can be displayed individually and a SpanaScope combination is available. Some transmit signal can be visible but its
magnitude depends upon TX IF leakage in the rig.
The scale to the left is true for steady, constant amplitude signals, i.e. RTTY, PSK. The display
is averaged (averaging time set in the Display
tab) so that the amplitude of a varying signal (i.e. CW, SSB) is duty-cycle-dependent.
The red line is the VFOA frequency (you can change the colour). The sub RX is enabled and VFOB
is in blue The lighter stripe left of the
VFO lines is the passband (as you can see, LSB here), which will almost always coincide with the rig passband - in some modes and filter
settings it is possible for the SDR bandwidth to exceed the rig bandwidth.
The full height yellow line at the right is the result of enabling by a right click, when the
mouse can position the line and its dummy passband
anywhere in the display, moving VFOA to that frequency with a left click. A second right click will display a red line and dummy passband
for the sub RX and a left click moves VFOB to that frequency.
The passbands can be made more or less visible with the Alpha sliders in the Colours tab
For most rig types the passband is positioned over the carrier (VFOA) frequency in CW and Data
modes, generating the selected CW pitch
and RTTY tones. Swapping between CW and CW reverse will not reposition the passband, leaving the pitch the same (subject to calibration
error) but changing the tuning sense of the CW Pitch.
The sub RX cannot function past the edges of the full span width so if the VFOB is too far away
the NaP3 sub RX is muted, while VFOB
continues tuning.
The passband will respond to the width and shift settings with the K3, KX3, Yaesu and Orion
rigs. While the width responds smoothly, the
shift may cause the signal to 'warble' and display hysteresis briefly while moving, especially at high FFT Size settings. In practice this is only
disconcerting if the resolution is high for narrow band (RTTY, PSK, CW) signals in narrow passbands, in which case shift is of limited use.
The ability of the display to respond to rig shift and width will depend upon the rig. Full control
is available with the K3 & KX3 but owing to
CAT limitations, only partial control is available with some Yaesu and very little with Kenwood.
When rig RIT and/or XIT, or SPLIT are enabled, vertical yellow lines mark the edges of the
potential transmit passband as a warning. They
always show the transmit frequency edges or carrier (ssb shown but works in other modes too) and provide a heads up display of when RIT
or XIT are activated. If you do not like or need this it can be disabled in the right click context menu on the SPLIT button.
