Installing Quisk for Windows

 

   Quisk is a software defined radio application program with versions for Windows and Linux. The following example shows how to install and configure Quisk on a Windows system. Installation of the Linux version is described in a separate article.

What is in this article?

     • Why choose Quisk?
     • Quisk Software and Documentation
     • Installing and Configuring Quisk
     • Customizing the Control Panel
     • Calibrating the SoftRock Local Oscillator Chip
     • Example of a Configuration File

Why choose Quisk for Windows?

   Compared with other SDR software, the user interface of Quisk is simpler, and non-programmers can modify it. This access helps experimenters, and it's a desirable feature for vision-impaired hams. You can select colors and font sizes that increase the visibility of the controls.

   The Quisk Web page describes limitations of the program:

   "Before installing Windows Quisk, first think about whether you really want to do that. Quisk is a simple SDR program meant for experimenters and homebrewers. It doesn't have all the features of PowerSDR, and it has no menus to adjust its parameters; you must edit a config file to even change the sample rate."

Quisk Software

   Quisk is freeware by James Ahlstrom, N2ADR. The Windows version works with Windows XP and Windows 7. A link to download the software is on the Quisk Web site along with installation/configuration instructions and a help file for beginners.

   For this example, I installed Quisk 3.6.11 on a Windows 7 system and tested it with a SoftRock RX Ensemble2 radio.

   The Quisk documentation lists steps for downloading the software. Before installing Quisk you install a 32 bit version of Python2.7 and wxPython. I used the Python 2.7.5 Windows Installer, the wxPython2.8-win32-unicode-py27 package installer (both links are in the instructions), and finally the Quisk-3.6.22.win32-py2.7.msi installer.

Configuring Quisk

   Quisk does not have traditional Windows menus. Instead, the configuration settings for the program are in two files:  quisk_conf_defaults.py and quisk_conf.py.

   The quisk_defaults.py file is located in the Quisk folder of the Python27 directory, typically C:\Python27\Lib\site-packages\quisk\. It's preferable not to edit this file because changes are lost if you update Quisk.

   To configure Quisk, edit quisk_conf.py. Entries in this file over-ride the default configuration.

   The first time Quisk runs, it creates a quisk_conf.py in your Documents folder. Replace this file with one of the same name but written specifically for your radio. Configuration files for various radios are provided in the same Python27 Quisk folder where quisk_conf_defaults.py is located.

   For example, the conf_rx_ensemble2.py file is located in the Softrock folder, typically C:\Python27\Lib\site-packages\quisk\softrock\. Rename it quisk_conf.py, and replace the quisk_conf.py file in the Documents folder, which is typically C:\Users\[Username]\Documents\.

   The quisk_conf_defaults.py file demonstrates the form of statements to use in quisk_conf.py. You can use the Python IDLE text editor to read and edit these files. Right-click on the quisk_conf.py file and select "Edit with IDLE." Save your changes.

   An example of a quisk_conf.py file for the Ensemble2 is included at the end of this article. Unlike the Linux version of Quisk, no sound card specifications are necessary for Windows.

Customizing the Control Panel

   You can change the colors and font sizes in the control panel for better visibility. The defaults are in the quisk_conf_defaults.py file along with an example of an alternate, dark color scheme by KB8RWQ. (A "#" symbol beginning a line indicates a comment or an inactive example.)

   Figure 1 shows the default control panel colors. I added the following statement to the quisk_conf.py file to increase the size of the button labels in the figure to 14 points (default = 10 pt.):

                  button_font_size = 14

FIGURE 1. Control Panel with default colors and larger button labels.

   Colors are specified using numbers or the name of the color. For example, the following line in quisk_conf.py will change the button background to red:

                  color_btn = 'red'

Calibrating the SoftRock Local Oscillator

   Before calibration of the local oscillator chip in my radio, the 14.0475 MHz signal from W1AW appears on the Quisk spectrum at 14.0596 MHz.

   Current SoftRock radios use an Si570 chip for the variable frequency local oscillator. This chip uses an internal fixed-frequency crystal as a reference for synthesizing the local oscillator frequency. Before calibration, the Si570 is programmed to use a nominal crystal frequency of 114.285 MHz to calculate settings for the synthesizer. Recalibration is necessary because the actual crystal frequency varies from one Si570 device to another.

   Calibrating an Si570 chip involves figuring out what the actual crystal frequency is and instructing the chip program to use it instead of the nominal frequency.

   Here are two ways to calibrate the chip. In each method, first tune Quisk to a signal with a known frequency. Record the "real" frequency and the "tuned" frequency (where it appears on the spectrum).

Method 1.  Calculate the crystal frequency with this formula:

          Xtal_Freq = 114.285 x (Real_Freq / Tuned_Freq) MHz

For my radio,

          Xtal_Freq = 114.285 x (14.0475 / 14.0596) MHz
                         = 114.187 MHz

Then add the following two statements to the quisk_conf.py file, substituting the frequency you calculated:

          si570_direct_control = True
          si570_xtal_frequency = 114187000

Method 2. Use the Si570 Configuration Utility by PE0FKO:

   Download and install the USB driver for the Si570 chip and the Si570 Configuration Utility.   

   Connect the computer to the USB port on the radio and start CFGSR. A small green dot in the lower left corner of the opening screen indicates a functioning USB connection (Figure 2).

FIGURE 2.  CFGSR Configuration Utility.

   If the USB device is not found, the small dot is red. For Windows to install the USB driver, sometimes it is necessary to unplug all USB devices from the computer and re-insert the USB cable for the radio first. After a Windows popup message that the new USB driver is recognized and installed, you can reconnect the other USB cables. It is not necessary to repeat this process on future startups of the program.

   Select the Calibrate tab and click "Reset" if you have previously used CFGSR with this chip.

   Enter the tuned and real frequencies in the Calibration B section. Clicking the Calibrate button displays the calculated crystal frequency (Figure 2) and stores it in the chip.

   At this point the chip will remain calibrated when the power is off and if a different SDR program, such as HDSDR, is used.

Configuration File Example

   Here is an example of a quisk_conf.py configuration file for a SoftRock RX Ensemble2 receiver:

          from softrock import hardware_usb as quisk_hardware
          usb_vendor_id = 0x16c0
          usb_product_id = 0x05dc
          softrock_model = "RxEnsemble2"
          button_font_size = 14
          # Swap the I and Q channels for correct sidebands:
          channel_i = 1
          channel_q = 0 

 

Acknowledgment

   Thanks to Ethan Blanton, KB8OJH, for answering my questions about Quisk.

Author Information

   Peter DeNeef, AE7PD, is an Extra Class amateur radio operator in the U.S. This Web site has no ads or conflicts of interest.
Email:  HamRadioAndVision "at" gmail "dot" com.

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rev. 8/25/2013