Are you interested in who is currently active on QO-100? Kto vysiela v CW, odkiaľ sa ozývajú stanice FT8 and how strong is your signal? You no longer have to search for answers by manually tuning the transponder. OK1CDJ spustil webový QO-100 FT8/FT4/CW skimmer, which continuously decodes the operation on the narrowband transponder of the geostationary satellite and displays the results directly in the browser.
You will read in the article
How the skimmer works
Skimmer on the site qo100.ok1cdj.com spracúva tri módy: FT8, FT4 a CW. Zvuk na dekódovanie pochádza z BATC WebSDR, the British Amateur Television Club's public web receiver for the QO-100 narrowband transponder. The author expressly thanks BATC on the site.
Skimmer monitors FT8 10489.540 MHz 5 Dec DT 0.3 s, FT4 10489.540 MHz 0 Dec DT 0.2 s and CW 10489.510–10489.530 MHz. The server is sponsored by QRO.cz and data on DXCC countries comes from Club Log.
DeepCW: telegraphy through a neural network
It uses a skimmer to decode CW DeepCW, projekt zverejnený na GitHube ako web-deep-cw-Decoder from developer e04. It is a real-time morse code decoder based on neurónovej sieti. Samotný model je v samostatnom repozitári deepcw-engine.
The author of DeepCW reports impressive test results:
- 0.00% errors at SNR from 0 to −4 dB at all speeds tested,
- less than 1.5% errors at −8 dB,
- less than 8% errors at −10 dB.
However, it should be added that the test only considered white Gaussian noise (AWGN) and the results apply to the HIGH mode.
Filters, map and statistics
The main part of the page is a live list of spots with UTC, mode, SNR, DT, frequency, report, tag, locator and DXCC columns. You can display 25, 50, 100 or 250 last lines. You can filter by mode (all, FT8, FT4 or CW) and with the CQ only switch you will keep only the stations that call the challenge.
The spot map shows the locator squares of the heard stations. The darker the square (with a light theme), the more marks. For CW stations, the locator is taken from their FT8/FT4 sessions or from QRZ.com. The map has two modes, Digi and CW, and you can click on a square to see its markers.
Statistics are offered for the last 24 hours, 30 days or the entire period:
- an overview of DXCC countries with the number of brands and spots,
- overview of VUCC squares,
- 10 most active stations,
- 10 strongest stations in the last 24 hours.
What is a skimmer good for in practice?
The skimmer gives an instant overview of what is happening on the QO-100 before you even turn on your own station. You can see who is calling CQ, which countries and squares the stations are calling from, and thanks to both DXCC and VUCC statistics, you can easily spot rarer stations.
It is also useful for checking your own signal. If you are currently broadcasting FT8, FT4 or CW, you can check in the list if the skimmer has caught you and with what SNR.
Other tools OK1CDJ
The QO-100 skimmer is not the author's only project. On the page apps.ok1cdj.com you will find other web tools for radio amateurs, for example FT8, the FT8Web client running directly in the browser, the kQSO log, WSPR Antenna Lab na porovnanie antén či DX Radar. If you like the skimmer, you can support the author via "Buy me a coffee".