GSpec V2.0 is a Spectrum Analyser for Windows 95,98,2000 and NT 4. It utilizes the installed soundcard to digitize and display the audio spectrum in a number of different display formats. GSpec features:
Follow these steps to install GSpec on your system.
Control the input to GSpec using the Windows Recording Control. Double click on the Volume Icon in the Windows Task Bar to run the Play Control. Access to the recording functions (input) is via the Options menu. Select Properties->Recording and press OK. The Record Control window will display. Make sure the input you want to use is selected. Set the input levels with the slider control.
You can connect the audio output of a Radio to GSpec. If your Radio (or other audio device) has a Line Out; connect this to the soundcard Line In jack. You can also use a microphone placed near the audio source you wish to view, but this may introduce background noise. Use the Recording Control to select any audio source as an input, like your CD audio for instance.
Control the cursors by dragging your mouse across the display window. The RED cursor follows the RIGHT button and the GREEN cursor follows the LEFT button. Read the values from the appropriate cursor display. The SHIFT is the frequency or time difference between the cursors.
Spectrum Display
Press this button to display audio in the frequency domain.
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Waveform Display
Press this button display the audio in the time domain.
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Sonagraph Display
Press this button to display the audio frequency over time. Audio amplitude is indicated by the colour of the signal display. Darker display indicates higher amplitude audio.
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FSK/CW Cursor Tracking
Select the type of cursor tracking you wish to employ. FSK tracking will track the two highest audio peaks in the Sonagraph and Spectral display modes. CW will track a single audio peak. Adjustment of the averaging setting (Settings Window) will provide more stable tracking. To disable tracking, press the selected button once. Up equals OFF.
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Settings Display
Press the button to pop up the Settings Display window.
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File Save and Open
Save screen displays to file using the save button. This button only becomes active when the display has been frozen. Open files you have saved using the file open button. Files can also be opened using a bitmap editor. Files are standard windows bitmaps.
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Freeze Display
Press the button to freeze the display. You can still make measurements using the cursors with the screen frozen. The File Save button is enabled when the screen is in the frozen state.
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Buffer Over-run Indicator
The Over-run indicator flashes red whenever a buffer of audio data has been missed. This may occur if your computer is busy doing something else. You may notice this when you resize or move a running GSpec application window. The indicator will also flash if you increase the display size too large for the performance of your computer. In this case reduce the GSpec window size, or reduce the sampling rate to give your CPU a break.
When in Spectrograph display mode Sweep is less CPU intensive than the Flow setting.
When you purchase GSpec you will receive an activation file by email. The Registration process will install this file to provide full program operation. Run the “Register.exe” program from the GSpec program directory (or Icon) and point the registration process to the file. You should copy (backup) the registration file to floppy disk and put it in a safe place.
Un-registered versions of GSpec will perform with all features for 30 days from installation, after this time it will revert to a version with reduced features. A Fax order form in included with the GSpec installation. Details are on the form – fax.htm in the GSpec directory or at the MRX Software web site.
Spectrum Group
- Gain: Adjust the gain of the Spectrum and Sonagraph display.
- Bandwidth: Adjust the bandwidth up to Nyquist frequency Spectrum and Sonagraph display modes.
- Averaging: Smooth the Spectrum display by averaging the audio over time. This makes measurement of some audio sources easier and more accurate.
Waveform Group
- Gain: Adjust the gain of the Waveform display.
Sampling Group
- 48Khz: 48.000 Khz sampling rate, 24.000 Khz maximum bandwidth.
- 44Khz: 44.100 Khz sampling rate, 22.050 Khz maximum bandwidth.
- 22Khz: 22.050 Khz sampling rate, 11.025 Khz maximum bandwidth.
- 11Khz: 11.025 Khz sampling rate, 5.125 Khz maximum bandwidth.
- 8Khz: 8.000 Khz sampling rate, 4.000 Khz maximum bandwidth.
Sonagraph Group
- Flow: New display activity is written to the top of the screen, pushing previous display activity downward. This is the most CPU/Graphics card intensive display method. Use the Sweep display method if your PC has trouble keeping up.
- Sweep: New activity scrolls down the display overwriting old display data. When the new display line reaches the bottom the activity wraps to the top of the screen. This is the least CPU intensive display method.
GSpec Spectrum Display
Here is a frequency spectrum display of an FSK (RTTY) signal.
GSpec Waveform Display
Here is the waveform display of an ARQ signal. It looks like a sine wave, but it came from an ARQ transmission. Digitisation rate was 48.000 kHz using an SBLive soundcard.
GSpec Sonagraph Display
This display was captured on 8 MHz; there is some ARQ and a Morse code transmission. The Morse reads CBV, from top to bottom. Notice the red and green cursors at the top of this display too. Use the cursors to measure the audio frequency.
Comments or suggestions? Please email jwsamin@mrx.com.au
GSpec V2.0 © MRX Software 1999
International Ph/Fax +61 2 62940242
Local Ph/Fax 02 62940242
