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Showing content with the highest reputation since 04/28/2015 in all areas

  1. 2 points
    WBT apps are limited to 30% processor usage and 500 megabytes of ram. Exceeding these limits will cause the app to be terminated.
  2. 1 point
    What computer is used in the WBT? How much processing power is left for me to create my app?
  3. 1 point
    For clarity, I wanted to add to this that GPS can be handled in multiple ways by the WBT system. There is a GPS input antenna (active) which will allow a built in GPS receiver to decode the NMEA data as well as provide timing (1 PPS based) and improved Frequency Accuracy. This decoder will tag the recorded QVRT files with GPS position data as well, plus there are some apps like GPS Display. which will allow you to see the GPS Data. Additional, either of the tuners can be used to record the RF of a GPS signals. This is very useful for recording the GPS RF and using it on playback with other data recorded on the 2nd tuner to provide time and frequency stability when decoding the data. A Tech Note Recording/Playback of GPS Signals is available to discuss the details of doing this. GPS is a very weak signal, so the operator must take care when setting up the device on RF Recording to make sure they are in fact getting the signal they need. Please contact us with any additional questions, and one of our team can help make sure your GPS recording and playback experience goes off without a hitch.
  4. 1 point
    The WBT uses a VRT compatible file format for its recordings. The WBT Developer's Kit (click the link for Q&A topic on this kit) details how to get a copy of the format if you need it, of contact us using our contact form.
  5. 1 point
    The WBT uses a chain of broadband Low Noise Amplifiers (LNAs) to minimize noise figure and provide high sensitivity. The LNAs can be internally attenuated via the Rx Attenuation setting, to reduce the sensitivity of the receivers for more powerful signals. The Special Use RF paths have an additional broadband LNA to provide the lowest noise figure, and to receive signals below -120 dBm.
  6. 1 point
    How often should I re-calibrate my WBT, and how do I do it?
  7. 1 point
    The current software ( provides a RBW that is BW/1024. A bandwidth of 40 MHz will have a display RBW of about 39 kHz. In the next major release the display RBW will be adjustable. What's recorded is complex time data which is unaffected by the RBW setting. Some of a data stream (typically < 1%) is used for a trace display. In general, a data stream from a digital tuner or the data drive is available to an embedded application so we can do whatever is required to generate the display information needed.
  8. 1 point
    There are numerous places where WBT can be utilized: spectrum analysis, spectrum triggering, repeaters, down conversion, network analysis, or anything else you can imagine. If the application you wish is not available or doesn’t work the way you wish it did, you can build (and even resell through QRC’s partner network) an application you design in house using common tools and languages such as C++, Python and familiar programming environments like Qt. For more information look here http://forum.qrctech.com/topic/14-how-can-i-get-the-wbt-developers-kit/
  9. 1 point
    Under what circumstances would I be better off using the "special use only" tuner inputs and why?
  10. 1 point
    The Rx special purpose port is able to provide a software‐switchable 3 VDC output to drive active antennas (such as when recording GPS), as well as providing an additonal nominal 15 dB gain on the input signal, useful for recording weak signals directly. It is also useful if recording and playback is to be accomplished at the same time without switching cables.
  11. 1 point
    The WBT has two RF inputs, the general purpose Rx/Tx port and the special purpose Rx only port. The Rx special purpose port is able to provide a software‐switchable 3 VDC output to drive active antennas (such as when recording GPS), as well as providing a nominal additional 15 dB of gain, useful for recording weak signals directly. It is also useful if recording and playback is to be accomplished at the same time without switching cables.
  12. 1 point
    When predefined WBT templates are utilized, no changes to the qt project (.pro) file are required. Otherwise, the TARGET in .pro is automatically specified as the name you chose for the project in the project wizard.
  13. 1 point
    There are multiple ways to skin the cat... This is what i do... 1. From inside the DEV VM: Create Project, then select WBT App. Finish going through the wizard by fill in all the settings as you wish! 2. Open up the mainwindow.h... and make the following mods: //NOTE: warning: The following line blocks the instantiation of MainWindow //WbtBroadcastMessenger m_messenger; WbtApi::WbtBroadcastMessenger* m_wbtBroadcastMessenger; //ONLY INSTANTIATED if WBT IS ON THE LAN 3. In the same file (mainwindow.h), use the following code (i place mine right under the 'using namespace std;' on LINE#7: //IF : this is a RELEASE build... //THEN : ALLOW m_wbtBroadcastMessenger TO BE instantiate #ifdef QT_NO_DEBUG #define WBT_ON_LAN true #else #define WBT_ON_LAN false #endif 4. In the file mainwindow.cpp, place the following code in your constructor: m_wbtBroadcastMessenger = NULL; if (WBT_ON_LAN) { m_wbtBroadcastMessenger = new WbtApi::WbtBroadcastMessenger; m_wbtBroadcastMessenger->broadcastFilter( "wbtclient", "", "" ); m_wbtBroadcastMessenger->setIncomingMessageCallback( MessageCallback, this ); } 5. Choose a build type (are you running it in the DEV VM?, OR are you running it with WBT resource?) Select DEBUG build if you want to run it in your DEV VM with no WBT resource. Select RELEASE build if you want to build for with a WBT unit. note: build for DEBUG, and it will not block! When your ready to test on your WBT, build for RELEASE.
  14. 1 point
    It is highly recommended using the fully configured Development Environment that QRC provides. More on that topic can be found here: http://forum.qrctech.com/topic/14-how-can-i-get-the-wbt-developers-kit/ . But if you want to do development on your own Ubuntu installation, it is recommended that if the "non-Ubuntu" version is 2.5.2 (64 bit) or greater and matches the documentation then use that.  Otherwise, if the Ubuntu version is installed and does not match the requirement be sure to uninstall it before installing the "non-Ubuntu" version 2.5.2 (64 bit).
  15. 1 point
    WBT will record whatever energy is there in the frequency range of the span.  If the signal is really weak you may want to play around with the gain and amplitude for record and playback.  There is a manual way to amplify a playback signal by utilizing TX Gain.
  16. 1 point
    ​In release 2.4 (Expected early June), we anticipate that users will be able to set an effective sample rate they want in the output data independently of the collected bandwidth. This feature will allow a 10 MHz LTE signal to be sampled at 30.72MHz for digital processing of the file.   This does not mean we will not, as discussed by Gene, over sample the input signal at the A/D even in this case.  Rather, it means we'll allow the user control of the logged sample rate in the file and in the API streams and not necessarily all the behind the scenes processing that generates it.  The goal of the WBT is to make it easy to use by the 'end user', and to provide output files of the format desired with minimal the chance of error.  To make that possible, our RF engineers simplify many of the "hard" things (like amplification, mixing, and filtering) that cause problems with other radio systems to focus on getting the best possible data to the output file.  We think this is a positive value-added approach to building a Software Defined Platform, not simply releasing a Software Defined Radio.  This Tech Note: https://www.qrctech.com/Articles.asp?ID=285 may interest anyone wanting to read more about all the things the WBT takes care of "Behind the Scenes" to make the product the easy to use end-user field employable solution it is.  
  17. 1 point
    The initial sample rate is adjusted, based on tuner settings, to significantly over-sample the input signal. After digital mixing and filtering, the effective sample rate of the data saved to disk is twice the bandwidth selected when the file was collected. The bandwidth and sample rate values are embedded in the QVRT context fields.
  18. 1 point
    Audio is an upcoming feature currently slated the WBT 2.3.3.* release, and will accessible to developers through utilization of the Advanced Linux Sound Architecture libraries. Once released, Users will simply connect their USB Audio device to any available port on the WBT, gaining access to whatever audio their favorite Apps are serving.
  19. 1 point
    Overview: Im interested in developing a simple app which i can click on a signal and listen to it. I do not see HW support for that (i.e. an headphones jack...) Do you have a solution?
  20. 1 point
    ​ In addition to what Steve wrote, the processor itself used on the WBT changes over time based on what's available, generally updating to newer/faster CPUs when it changes. As of today's date, the current processor being shipped on WBT systems is a dual-core processor with hyper-threading. It has 8 GBytes DDR3-1333, Intel® Core™ i7 2.4 GHz Turbo, 4MB L3 cache, with HD3000 graphics. Please feel free to contact us here or using the link above for the currently shipping CPU configuration. Note that the numbers provided by Steve are per app and enforced by the System Monitor. Should more capability be required for your solution, please contact us and we can discuss your specific needs.
  21. 1 point
    I believe that this question can be best answered by our page on the WBT's Sensitivity- http://www.qrctech.com/articles.asp?id=268
  22. 1 point
    First, a disclaimer: There is no standard definition for sensitivity. Generally speaking, sensitivity is the minimum signal level (Smin) that produces an output with a specified signal-to-noise ratio (SNR). The term minimum detectable signal (MDS) is often used for Smin but is different because "detect" can mean "strong enough to demodulate" or strong enough to rise N dB above the noise floor so the measurement results will vary with modulation type. And, since the noise floor depends on the selected bandwidth, sensitivity does, too. The MDS for the WBT is about -130 dBm with BW = 781 kHz on the standard (RX/TX) input.
  23. 1 point
    How do I read IQ Data while playing back a file? Do I use the QVRTReadIterator?
  24. 1 point
    Use WbtApi::WbtVRTReadIterator, connect it to the desired stream on playback, check that your current packet type is IF Data by calling getCurrentPacketType() and checking for a return of 1. If it's not, use the ++ operator to increment the iterator and try again. When getCurrentPacketType returns 1, you can use the getCurrentIQDataFloat ( float*, int) function to fill a float array with IQ samples. The samples are ordered with I and Q alternating ( the array starts on I, then the value after it is the related Q, then the next I, etc). This should get you pointed in the direction you need to go, I highly suggest referencing the API documentation to see the usage of the listed functions.
  25. 1 point
    There's a lot of information on the Development Environment here, and on QRC's main website (Click QRC Home Page Above). The SDK is free of charge, and includes a fully development virtual machine which has all the tools, APIs, and drivers needed to begin creating your own WBT Apps. The SDK will require a NDA (QRC's standard NDA is attached) be signed between you and QRC, after which links will be provided for easy download.. Please feel free to contact us at qrcinfo@qrctech.com, or post here and we'll get you what you need to get up and running quickly. 120113 QRC Bilateral NDA Template.pdf