January 30 2022

QT vs QIRX – RSP1A vs R820T

For DAB+ DXing QIRX and QT-DAB are great software, while RSP1A and RTL-SDR R820T are excellent hardware. The software is free thanks to excellent work from Clem Schmidt and Jan Van Katwijk.
The differences between the set-ups are minimal and price-quality wise RTL-SDR R820T is a fantastic product for DAB+.

I connected my antennas to a splitter to run QIRX and QT-DAB simultaneously. On the most MUXes there was no noticeable difference. However when doing the test in rainy, windy weather with dismal lift QT-DAB4.3 + RSP1A managed to decode
12B Liège quite easily.
QIRX3.2.1 + RSP1A managed it too but with more difficulty and most of the time only partially. QT-DAB and QIRX couldn’t do it when connected to the RTL-SDR R820T. Under normal conditions the difference between the set-ups became negligible.

It’s vital to set-up bandwidth for QIRX + RTL-SDR R820T correctly to around 1700 kHz. AGC works very well in this combo. For QIRX + RSP1A do check the Gain Reduction. Its default setting is 3. The higher the number the more reduction!
In general QIRX tends to show the TII codes quicker and more extensively than QT-DAB.
QT-DAB settings need to be checked too. AGC works well. Using RSP1A again note the LNA state selector indicate the Gain Reduction. The higher the number the less Gain. Using RTL-SDR R820T with the Autogain on you should toggle the ppm.
In general strong MUXes need a lower ppm.

Do have a look at the manuals from QIRX and QT-DAB.