User's Guide

WR-3700 Series User’s Guide

Spectrum Scope

The ‘Spectrum Scope’ is a utility to display and store the signal level across a frequency

range. After a frequency sweep has been performed, you can tune to any frequency on the

display. To tune to a frequency or peak on the display, click on it. You can hold down the

mouse button and drag the cursor across the display quickly tuning to any frequency on the

display (this facility will be described in greater detail under chapter heading ‘VisiTune’).

You can even configure it to tune another receiver card into the selected frequency. Double-

clicking finds and tunes to the closest peak.

Mathematical functions can be applied to the sweeps to help find transmissions you are after.

Every sweep is recorded and can be saved to a file to be viewed at a later time and different

analytical functions applied to the data. Markers can also be added to the sweep, and the

sweeps can be printed.

Spectrum Sweeping

To perform a spectrum sweep, you have two methods of specifying the frequency range.

You can either specify it by the start and stop frequencies, or by the centre frequency and the

width of the sweep. To specify a sweep method, see the following section on ‘Options’.

Next, you specify the step size depending on the resolution and speed you want. The

resolution bandwidth (RBW) also has an effect on the step size. For a slower, higher detail

sweep, select a small step size, and in contrast, for a quick, coarse sweep, select a large step

size. For example, if you are using the 17 kHz RBW, step sizes below 10 kHz are not useful;

all signals would be captured at 10 kHz. A 5 kHz step is suitable for a fairly detailed sweep

using an RBW of 6 kHz. If you select a step size larger than the RBW, it is possible that

signals will be missed that are located between two stepped frequencies.

Once you have specified the parameters, click on the Sweep button to perform a sweep.

Every time you change any parameter (except the resolution bandwidth), any previous

sweeps will be cleared when you start a new sweep. The bandwidth can be changed at any

time, even in the middle of a sweep. Up to 200 sweeps will be stored. If more than 200

sweeps are performed with the same parameters, then every successive sweep will delete the

earliest sweep recorded.

To stop a sweep prematurely, click on the Stop button (which is the ‘Sweep’ button with a

different caption). If you stop, clicking on the sweep button again will start a new sweep

from the start (but the previous sweep will be preserved until a parameter is changed).

Alternatively, you can click on the Pause button to pause the sweeping and click on it again

to let the scope resume from the frequency it was paused at.