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Spectrum sweep


When a spectrum sweep is operational the band change and scan buttons are inactive.  You can still change mode, store memories in the permanent memories, store frequencies in the QMB memory bank and empty it.  You cannot switch forwards and backwards with the QMB banks until the sweep is paused by clicking on it.

The spectrum sweep alternates colour and drawing width on each sweep, so it is easy to see changes between sweeps. 

Defining the sweep

The controls for governing the start frequency, step size and sweep width are drop-down combo boxes at the lower left-hand of the screen.

On initial start-up the start frequency is 'Start'. This will start at the frequency you are presently tuned to. Click the drop-down triangle and either select a pre-defined start point or type in one of your own choice.  

The step size (in kHz) is the tuning increment across the sweep. Click the drop-down triangle and either select a pre-defined step or type in one of your own choice.

The sweep width is the number of kHz to scan. Click on the drop-down triangle and either select a pre-defined width or type in one of your own choice.

If you type in your own frequency, step size or sweep width then press the TAB key instead of the ENTER key.  The number you typed will then be used instead of one of the pre-defined ones.

Starting/stopping a sweep

To start a sweep click the Start button.  To re-start a sweep do the same.

To stop the sweep process altogether, click the Finish button. 

Investigating peaks and troughs shown

While a sweep is in progress, moving the cursor cross-hair to any position on the sweep shows you the frequency of that position in the bottom left-hand corner.  

Click once anywhere on the spectrum display to stop the sweep and tune to that frequency.  

When it is not sweeping the S-meter display does not update.

Tuning by mouse

Click with the left mouse button and drag across the whole of the spectrum display to perform tuning in 'step size' increments.  

Click with the right mouse button and drag to have a fine tuning facility.  

Hold down the CTRL key and then click and drag and the tuning rate is doubled.

Resuming/restarting a paused sweep

To resume sweeping from the point at which you stopped by clicking on the sweep display, click the Resume button. 

To restart at the beginning of a sweep click the Start button.

Factors affecting the sweep speed

The speed at which a sweep occurs is dependant on the operating system used (Windows NT/2000/XP are fastest), Command delay, S-meter delay and Talk Speed settings.