You can configure device-specific settings for the R5500, including signal attenuation, gain, and reference clock, from the VSA application, as described below.
Note: Gain and attenuation settings allow the R5500-VSA application to accommodate very weak signals as well as strong signals. You must remain within the signal strength levels specified in the R5500 data sheet to avoid saturating or damaging the device.
- In the VSA application menu bar, open the Input menu, and select the Extensions … option from the drop-down menu.
The Input dialog window opens and displays the Extensions tab.
On the Extensions tab, set values for the following parameters:
• Attenuation (db): sets the attenuation of the input signal to one of four attenuation levels (0, 10, 20, or 30 dB).
• Gain: controls the gain blocks inside the Front-End of the R5500 device, where three gain levels are available (low, medium, or high).
Note: The ThinkRF R5500-408 device and its variants have no controllable gain stage. Therefore, gain setting is set to “NotApplicable”
• Level Trigger: specifies the trigger configuration, where four parameters are available:
▪ Lev. Trig. Start Frequency (Hz): specifies start frequency for the triggering window in Hz.
▪ Lev. Trig. Stop Frequency (Hz): specifies stop frequency for the triggering window in Hz.
▪ Level Trigger Enabled: enables/disables level triggering.
▪ Level Trigger Level (dBm): specifies the triggering threshold value in dBm.
• Reference Clock (10 MHz): specifies the source of the 10 MHz reference clock. You can select the internal (built-in) 10 MHz source, or an external source.
If you are using an external source for the reference clock, you must connect it via the associated port on the rear panel of the R5500 device (10 Mhz/IN), and carefully consider input damage levels.
The LED associated with the external reference source has the following states:
▪ Solid green: Internal reference frequency is selected.
▪ Blinking green: External reference frequency is selected, and an input source is connected.
▪ Blinking red: External
Note: When you add a new measurement to a R5500 device in the VSA application (MeasSetup > New Measurement), you must close the Input dialog window first.