For a long time, I've been wondering whether JTDX has fallen behind WSJT-X in its sensitivity to WSPR signals.
For some reason, I never simply saved a set of receive runs and worked out the numbers.
So, this morning, that's exactly what I set out to do.
Reception was carried out at 14MHz using a Yaesu FT-450, in a stable operating temperature, having run continuously over the past 36 hours. Recordings of the time slots were made, and then played back for decoding 'offline' by each software.
Number of 2-minute time slots: 21 (42 minutes total data gathering)
Time of recordings, including gaps between switchovers/other activities: 07:18UT - 08:20UT.
Recordings made using JTDX v2.0.2-rc139 (Release Candidate) as the receiving software:
JTDX decodes: 97
WSJT-X decodes: 105
Recordings made using WSJT-X General Release 2.1.0 as the receiving software:
JTDX decodes: 104
WSJT-X decodes: 117
Combined spots for all runs:
JTDX total spots: 201
WSJT-X total spots: 222
Only in one time slot (07:38UT) out of 21 did JTDX decode (one spot) more than WSJT-X.
A check was made that 'live' decodes were no different to decodes from saved recordings. There were no such differences.
So, the firm conclusion is that WSJT-X is 10.4% better than JTDX, at least in their current forms, accepting that both softwares are in continuous development, and that the JTDX version used is a RC, not a General Release version. Importantly, JTDX developers have tended to focus on FT8-based HF DXing aspects of their software over the past months, whereas WSJT-X WSPR performance has been improved - clearly rather successfully.
It's likely that, at different times of the day, notably into the later evening at present, when most signals are weak at 14MHz, WSJT-X will prove to outperform JTDX by a wider, possibly much wider margin. More on that as data is gathered...
Showing posts with label WSJT-X. Show all posts
Showing posts with label WSJT-X. Show all posts
Thursday, 15 August 2019
Friday, 21 December 2018
WSJT-X vs. JTDX - a quick test.
Yesterday, I reported on the SDRPlay RSP1a appearing to be a very good receiver, at least as good as my FT-450 transceiver.
That result, which got me to number 5 in the DX listening challenge, was using the latest version of WSJT-X, which is meant to have 'improved' WSPR sensitivity.
At just after midnight on 20/12/2018, I changed to using JTDX for WSPR reception over another 24 hours. So that I could tell the difference, I used plain MW1CFN as the call, rather than the MW1CFN/SDR used the previous day.
Was one software better than the other?
Well, I came in at number 6 with JTDX, four spots away from being number 5. Realistically, one can say this is an inconclusive result, especially as it only covers two full 24 hour periods. Those stations in the top 10 can move around a lot from day to day, mainly according to geomagnetic conditions.
Overall, the two softwares seem to be very similar. For general antenna performance checking, use of one over the other might be of no real consequence. For more critical work, the new WSJT-X may be preferable.
The weekend is now here, together with it's massive uptick in QRM. Therfore, SDR operations are given over to VLF reception, down at around 5kHz, with a new multi-turn wire loop (about 215m total wire!) that even got my daughter excited and busy winding last night! The flexibility of SDRs is really amazing, and opens up yet another lifetime of radio interest!
That result, which got me to number 5 in the DX listening challenge, was using the latest version of WSJT-X, which is meant to have 'improved' WSPR sensitivity.
At just after midnight on 20/12/2018, I changed to using JTDX for WSPR reception over another 24 hours. So that I could tell the difference, I used plain MW1CFN as the call, rather than the MW1CFN/SDR used the previous day.
Was one software better than the other?
Well, I came in at number 6 with JTDX, four spots away from being number 5. Realistically, one can say this is an inconclusive result, especially as it only covers two full 24 hour periods. Those stations in the top 10 can move around a lot from day to day, mainly according to geomagnetic conditions.
Overall, the two softwares seem to be very similar. For general antenna performance checking, use of one over the other might be of no real consequence. For more critical work, the new WSJT-X may be preferable.
The weekend is now here, together with it's massive uptick in QRM. Therfore, SDR operations are given over to VLF reception, down at around 5kHz, with a new multi-turn wire loop (about 215m total wire!) that even got my daughter excited and busy winding last night! The flexibility of SDRs is really amazing, and opens up yet another lifetime of radio interest!
Thursday, 20 December 2018
SDRplay RSP1a - progress so far.
Well, though it remains very early days, I can confidently report that the RSP1a recently acquired here is a very worthwhile product.
My normal WSPR listening (0% transmissions) over a 24hr period with a Yaesu FT-450 transceiver usually yields a place in the top 8, depending on conditions. I can be as high as the number one receiver on occasion. This much has been reliably established over a long period of operation.
So, how does the RSP1a do? Well, first it has to demonstrate that it can cope with electric fence spikes. This is the only RFI that is present locally at the moment. The FT-450 completely eliminates this very simple, slowly-repeating spark profile with a press of the NB button, restoring clean bands across the board.
The fences are currently damaged (they need maintenance with such regularity that few horse keepers can keep up with in a windy area like this) and so tend to be off. But when they have been on, I noticed the RSP1a noise blanking functions, when using the native SDRUno software, did not remove the spikes at all.
This would render the unit rather less than useful if the NB settings could not be modified. I later learned that there are threshold limit settings for the NB functions, so once the fences come on again, I will see how they work. I would be surprised if even the simplest NB function did not work in this context.
Anyway, back to the WSPR results. The past 24 hours yielded a number 5 slot, which is pretty much where I would expect to be on a typical day with the FT-450. At £89, and provided the NB can be improved substantially, that makes the RSP1a a very good performer indeed.
During my musings on SDR, I've (re)discovered the interesting GQRX software, which seems to be quite popular, not least as it is open source. I will try that later over the Christmas period, though contests might be a problem over the holidays. Then it's a move over to the Raspberry Pi. This should be fairly easy, but one never knows with Linux-based systems, especially when the user is less than expert, like me! If I can get it all to work, then it will be straight off into a less domestic setting in my farmland-based shack, or the beach.
My normal WSPR listening (0% transmissions) over a 24hr period with a Yaesu FT-450 transceiver usually yields a place in the top 8, depending on conditions. I can be as high as the number one receiver on occasion. This much has been reliably established over a long period of operation.
So, how does the RSP1a do? Well, first it has to demonstrate that it can cope with electric fence spikes. This is the only RFI that is present locally at the moment. The FT-450 completely eliminates this very simple, slowly-repeating spark profile with a press of the NB button, restoring clean bands across the board.
The fences are currently damaged (they need maintenance with such regularity that few horse keepers can keep up with in a windy area like this) and so tend to be off. But when they have been on, I noticed the RSP1a noise blanking functions, when using the native SDRUno software, did not remove the spikes at all.
This would render the unit rather less than useful if the NB settings could not be modified. I later learned that there are threshold limit settings for the NB functions, so once the fences come on again, I will see how they work. I would be surprised if even the simplest NB function did not work in this context.
Anyway, back to the WSPR results. The past 24 hours yielded a number 5 slot, which is pretty much where I would expect to be on a typical day with the FT-450. At £89, and provided the NB can be improved substantially, that makes the RSP1a a very good performer indeed.
During my musings on SDR, I've (re)discovered the interesting GQRX software, which seems to be quite popular, not least as it is open source. I will try that later over the Christmas period, though contests might be a problem over the holidays. Then it's a move over to the Raspberry Pi. This should be fairly easy, but one never knows with Linux-based systems, especially when the user is less than expert, like me! If I can get it all to work, then it will be straight off into a less domestic setting in my farmland-based shack, or the beach.
Subscribe to:
Posts (Atom)