User's Manual
Table Of Contents
- Table of Contents
- Introduction
- The Hardware
- Installation
- Getting Started
- Inside the Excelsior
- Resizing the Application Window
- Drop-Down Menu Controls
- Tuning the Excelsior
- Receiver Selection
- Mode Selection
- Function Tabs
- Spectrum Scopes
- Recording Functions
- Attenuator
- Preamplifier
- S-meter
- Top Menu Bar
- File
- Options
- Auto-mute RX not in focus
- Enable second RX
- Filter Length
- Front Panel LED
- Display Offset
- Time
- Keyboard Shortcuts
- VSC Set-up
- Audio Buffering
- AMS Capture Range
- Audio Output
- Show Measurements
- Show Data Rates
- Of particular interest to many users will be the CPU load (excessive CPU load may cause sluggish behaviour or freezing of the computer), and Audio latency. Apart from DDC bandwidth, CPU load may be minimized by reducing the Demodulator filter length (...
- Note: When measuring sensitivity using SINAD, it is very important that the Audio Filter is enabled and the cut-off frequencies (and for FM measurements, also the de-emphasis) are set according to the specified test conditions. Proper audio filtering ...
- Show Waterfall Timestamps
- Calibration
- Hand-Off Receiver
- Color scheme
- Restore factory defaults
- Memory
- Scheduler
- Scanner
- Logger
- Plugins
- Power Switch
- Date and Time Display
- Appendix A – SDR and DDC Primer
- Appendix B – Troubleshooting
- Appendix C – USB Interface Diagnostics
- Appendix D – Dealing with Interference
- Appendix E – G39DDCi PCIe Card Connections
- Appendix F – Waterfall Spectrum Palettes
- Appendix G – Recording File Formats
- Appendix H – Compliance Declarations
- Appendix I – Safety Disposal
WiNRADiO G39DDC User’s Guide
35
For LSB mode, dragging the right-hand edge of the greyed-out filter passband
results in tuning, dragging the left-hand edge results in adjusting the filter
bandwidth. For USB mode, the opposite applies. The edge that is used for
tuning is highlighted for operator convenience.
IF Shift and Passband Tuning
Dragging the greyed-out demodulator filter passband in the DDC2 spectrum
will result in tuning the receiver in a manner somewhat similar to the IF Shift
function in conventional receivers. The passband will move inside the
displayed spectrum and the tuned frequency will change accordingly.
In a DDC-based receiver, “IF Shift” is in fact a misnomer because there is no
“intermediate frequency”, but as this is a time-honored and commonly used
term for this function, we will still use it here for convenience.
IF shift makes it possible to tune the receiver by positioning the demodulator
filter precisely over the spectrum of the received signal, while keeping the DDC
passband located exactly where it is.
This makes it possible to quickly and visually tune to another station
represented by a signal peak in the spectrum. However, it is not very suitable
for the AMS, USB, LSB, ISB, DSB and CW modes if you only wish to adjust
the filter passband position slightly for the station you are currently receiving
(for example in order to avoid interference from an adjacent channel). If you do
this, and you are, for example, tuned to an AM station using the AMS mode, or
an SSB station using the USB or LSB modes, then moving away from the