This article describes the first maintenance release of the S240v5 Real-Time Spectrum Analyzer (RTSA) software, version 5.1.1. It is concurrently released with PyRF3 API v3.0.4 (PyRF3 is a Python 3 release of ThinkRF’s original Python 2 version of the PyRF).
This software is distributed as a single Microsoft Windows binary file ThinkRF_S240v5_RTSA_v5.1.1_Installer.exe.
Reminder: S240v5 supports current RTSA devices such as R5500, R5550, R5700, & R5750, but not obsoleted WSA products such as the WSA5000. End of life products are still supported by the S240 application v4.3.0 or earlier.
2 Fixed Defects
3 New Features
The following new features and capabilities appear in this release version.
a) Added the ability to have smaller RBWs down to 4 Hz depending on the Span range. In other words, the smallest RBW of any Span allowed will be one that matches the maximum of 500_000 data points displayed.
**Warning**: Usage of small RBWs in the Hz range (with Span under 5 MHz) could cause very slow sweep time due to the large data points for processing, which could take up to 1minute for RBW of 10 Hz or lower. Recommend to change RBW to a value above 1 kHz before using the Demodulation feature, since the Demodulation does not use this RBW setting. This is to allow for a smoother switching back to the main panel after closing the Demodulation panel.
4 Other Changes
The following changes appear in this release version.
a) Updated the S240v5 User Guide to reflect the new changes with added notes and warnings. The Demodulation section has been made as a main section and its content has been updated.
5 Known Issues and Limitations
5.1 Demodulation Feature
The Demodulation feature is still in the beta stage; thus, there are known issues associated with it as listed in this section.
5.1.1 Scrubbing and Stepping
Scrubbing and the associated ability to step through the signals has not been implemented in this release. Although it is possible to see the location of the playback within a saved stream using the slider below the graph section of the user interface, it is not yet possible to move back and forth manually. Nor is it yet possible to move frame by frame in either direction.
5.1.2 Audio Record and Playback
The audio streams after demodulation cannot yet be saved and played independently of the IQ data. To hear the audio again, it must be demodulated again from the original saved VRT stream.
5.1.3 AM Broadcast
The application cannot at this time tune down into the AM broadcast frequencies. This limitation may be addressed in the future.
- If Span is set to under 40 MHz, then after switching back from running the Demodulation feature for awhile, the data capture displayed in the main S240 panel might get stuck in the ‘block’ capture mode. This means changing of the Center Frequency will work but the sweep feature is no longer working. The work around for this is to use the Preset button or reconnect to the device from Device > Connect.
- If Auto RBW is unselected, then after switching back from running the Demodulation feature for awhile, the main S240’s Span or RBW will not be switched back properly. Suggest to save the settings (File > Save Settings) before using the Demodulation feature so that the settings could be reloaded from the saved *.config file (File > Load Settings).
5.2 Other Known Issues
- When Span is 25 MHz or lower, the data returned is of I & Q mode due to decimation used, the DC offset correction is then activated. This means that any frequency input from a signal generator that is aligned with the S240’s Center frequency will resulted in a ‘clipped’ input signal. Recommend to have the input frequency of the signal generator and the S240’s Center frequency to be at least 10 Hz off from each other to avoid such signal clipping.
- There are rare cases where the automated mode switching can result in a frozen display, click on Pause Capture, Single Capture, then Continous Capture to resume the capture. The cause of this issue is not yet understood.
- Sometimes, when a Level Trigger is active and the plot is frozen by lack of triggered data, switching to Free Run does not immediately restart continuous capture. This is easily remedied by clicking Pause Capture and then Continuous Capture.
- Before running the installation, recommend to turn off the anti-virus software. Some antivirus software might set off a false positive toward the PyInstaller application, which is used to generate the RTSA GUI executable from Python.
- During the installation, a Microsoft Certification warning might show-up. Accept the warning to continue the installation.
- Fine Tuning is still not yet available.