Two different sources have said JTDX decodes more stations than WSJT-X. Is this true? That is the theme of this project today. JTDX states it is “a derivative of work based on WSJT-X”. There are word of mouth claims that JTDX made improvements to the decoding algorithm. Today’s project used two identical radios and two similar computers connected to the same antenna through a splitter and the results were compared. One computer ran JTDX and the other WSJT-X. All were running the latest versions of software, identical settings, and levels. Here is what was found.
On some passes both applications had the same number of decodes and they were the same stations on both but most of the passes JTDX did indeed have more decodes. Here is a typical example of a pass taken at the same time slot. Compare the bottom left of the screens.
Observing the pass for time stamp 222930, there are 9 stations decoded by WSJT-X (upper screen), and 12 stations decoded by JTDX (bottom screen). Digging a little deeper the three stations not decoded by WSJT-X are CO8LY, KC8GCR, and K4TT. Were those stations too weak for WSJT-X? Apparently not because weaker stations were decoded by WSJT-X, for example, K2AJK and K1BDC. Are there clear indications of why those three stations were not decoded by WSJT-X? It needs deeper research. It is apparent that JTDX decodes more stations. The results speak for themselves.
Both radios are Icom IC-7300’s. The computers are both Intel NUC’s with Windows 10 and the latest updates. To verify the results the computers were swapped, the tests repeated, then the radios swapped, tests repeated, and finally the applications on the computers were swapped. None of the swapping around showed any changes in the results. The antenna was a random length of wire vertically oriented. The mode was FT8.
JTDX is available here: https://www.jtdx.tech/en/
WSJT-X is available here: https://physics.princeton.edu/pulsar/K1JT/wsjtx.html
Ive been doing similar tests on my IC-7610 with the 2 programs. On my end, it appears that signals reported on WSJT-X are a higher signal value than on the JTDX. But, JTDX does decode more per pass. Very odd.