QRSS reception with webbrowser software (2021)

-- Audio frequency (Hz): -- Tuned frequency (Hz):

Level (dB): - - - - --

Audio band (Hz): -- --

LITOPO version: litopo1.htm (2021-12-15) -- QRSS reception with a webbrowser
It is very simple! Connect the audio input of your PC, Tablet PC or Smartphone to your SSB receiver. Click a link in your webbrowser (Chrome or Firefox etc.) to -litopo1.htm- and the QRSS signals will be displayed on your screen! No extra software required, only the standard functions of your webbrowser software are used. Modern webbrowsers have audio processing software like a simple spectrum analyzer functionality that is used here. Sensitivity levels, level ranges, smoothing are all settings of this spectrum analyzer functionality of the webbrowser.
This simple program is intended as an easy way to get acquainted with QRSS. It has less fuctionality and is much easier to use than the more comlex and more sophisticated software programs. You cannot do an FTP upload and it is not possible to save a picture. You have to make a screenshot if you want to save a picture. Right click with your mouse on the picture or use the Print Screen button of your keyboard. The FFT sample length is limited to 32768 samples, so we have to downsample the audio sample rate to 9600 samples for a good performance.
It can only connect to the default audio device of your computer.

Long wave notes
Thanks to Mike N8OOU for the help with the Long wave settings!
For QRSS on Long waves, a dot time of 30-60 seconds is used instead of 3-6 seconds. And a shift of only 0.5 Hz. So we have to downsample even more to the lowest possible 3000 samples/sec. However, that is not supported by all webbrowsers! It is by Chrome, Chromium. And we would like to have a longer FFT array time length. However with the special Multi Smooth function, the performance of LIPOTO for the Long wave bands is also good! When 3000 samples/sec. is not supported, then the lowest always supported 8000 samples/sec. is taken.

Fill in the -Audio frequency- and -Tuned frequency- labels and press -Start-. Wait for the request for permission to use the audio. The button text changes from -Start- to -Set-. Press it when you want to change the frequencies later. If you want that the scan starts on exact multiples of 20 minutes, press -Set- at that moment. For USB reception, the SSB receiver has to be tuned to the LOWEST frequency of the QRSS band MINUS the -Audio frequency-. For LSB reception, the SSB receiver had to be tuned to the HIGHEST frequency of the QRSS band PLUS the -Audio frequency-.
The sensitivity level of the spectrum analysis. A lower value displays a brighter background noise.
The on the screen displayed range in dB. It acts like a kind of contrast. A lower value gives a higher contrast.
-Audio band-
The Audio band is the displayed frequency band on the screen from bottom to top. It can be set to 200, 300 or 600 Hz. For 300 and 600 Hz, the screen is resized by 50%. Set the audio band before the start of the reception.
The 50 Hz and 100 Hz Audio bands are for QRSS Long wave reception. Special settings for the QRSS long wave reception are also applied.
You can use it in Upper Side Band reception mode (normal) or Lower Side Band mode (special cases like my simple 80 meter QRSS receiver).
For the normal USB reception, the BOTTOM line of the grid is the tuned frequency PLUS the -Audio frequency-. For the special LSB reception, the TOP line of the grid is the tuned frequency MINUS the -Audio frequency-.
Smoothing reduces the noise a little but has the disadvantage that the shift transitions of the QRSS signal are less sharp.
Of course it is not convenient that you have to change the settings every time you start the program. But you can download it to use it locally and edit the first lines of the litopo1.htm script. I have a few with different names: litopo1m80.htm, litopo1m30,htm and litopo20.htm. Indeed, for 80 meters, 30 meters and 20 meters.

Popular bands:
10,139.800 - 10,140.100 kHz
7,039.700 - 7,040.000 kHz
14,096.700 - 14,097.000 kHz
137600 - 137800 Hz (2200m amateur band)
185300 +/-? Hz (LoFer band)

Little Toe Power!