Problem to decode station in FT8

Rickyfly · June 15

I submit an uncomfortable question to you,
I have an 8400M with software 3.9.18 in FT8 I do not encode distant or slightly uncomfortable station signals very well I struggle or I do not encode them at all. I followed your guide to set up WSJT-X. But if I connect another radio for example Yaesu I can encode the stations that I do not encode with the Flex with the Yaesu why? Where am I going wrong?

Erik Carling EI4KF · June 15

It is good. One advantage of BktTime is that if using WSJTx and the DXpedition clock is not accurate, you can set an offset in the Time Sync software to compensate. JTDX has this built-in. So I would stay with your current choice.

Erik Carling EI4KF · June 16

Yes perfect. You are all set thanks to Mike from Flex.

Erik Carling EI4KF · June 15

Tell us what your RX graph level is.

Rickyfly · June 15

From 50 to 60 in the scale meter

Rickyfly · June 15

in the DAX panel I have rx gain to 35, acg-t fast 50%

Erik Carling EI4KF · June 15

OK. All good so far. Next probably useless question is what are your SmartSDR mode and RX filter width when in FT8. Just trying to narrow down possibilities.

Rickyfly · June 15

like to your

Erik Carling EI4KF · June 15

Have you tried JTDX to see if the issue is the same? This FT* software has superior decoding over WSJTx but if you see a vast difference, that would point to some aberrant setting in WSJTx. If both the same, or nearly anyway, it is back to checking SSDR I would think.

https://drive.google.com/file/d/1SaEIe5u93JtRm6vCf1AS8B5HJy4jJA5O/view?usp=sharing

Rickyfly · June 15

Thank You Erik,

now I try to install it, I have installed the rc3 version.

however as jtd-x I use the 2.8 improved + versionI'll let you know soon

Erik Carling EI4KF · June 15

Ok that is fine. We shall see what happens. 2.8 improved was not very improved for me. I found that the official version was better

https://sourceforge.net/projects/wsjt/files/wsjtx-2.7.0/wsjtx-2.7.0-win32.exe

Rickyfly · June 15

it all looks the same

Erik Carling EI4KF · June 15

In other words, you see lots of stations in the waterfall but they do not decode. Can you visually determine if the number of stations in 3khz as seen in SmartSDR panorama is approximately the same as in the WSJTx / JTDX waterfall? I just wonder where the failure is …. SSDR or some mis-setting of the FT8 s/w.

Rickyfly · June 15

I don't know exactly how to verify this,

can you explain it to me well thanks

Rickyfly · June 15

this is my ssdr

JTD-X Waterful

Erik Carling EI4KF · June 15

ok sorry - I was wondering if approximately the number of FT8 stations that you see in SmartSDR in a period

in this case approximately 20 stations (zoom in so you can see the full 3khz bandwidth)

is the same as you see in WSJTx or JTDX. It is easier in JTDX because at the top is the number of decodes

which in this case is 19 stations. So the same for practical purposes. Is it similar for you?

Also, while in JTDX, what is your lag figure? This is the -0.72 above. What is yours?

Rickyfly · June 15

Erik Carling EI4KF · June 15

So you have 30+ stations being received by the radio but only 24 into JTDX.

Is your JTDX on the same computer as SmartSDR?

Rickyfly · June 15

yes same computer

Erik Carling EI4KF · June 15

Ok, for heaven's sake, haven't we covered everything and not gotten to the cause. You cannot say I haven't been thorough but I sure haven't been effective.

Open JTDX settings and post a picture of the Audio tab please.

Where are Mike and Len when we need them? Or someone else with better ideas than I have?

Rickyfly · June 15

Very scrupulous but this thing is to understand it's driving me crazy.The radio is connected to the PC via network no USB cableanyway thank you very much

Erik Carling EI4KF · June 15

Ok, nothing wrong with any of your settings that I can see. I did not expect to see any problem but had to check. I am sorry I cannot be of more help. Maybe someone will come in and have an idea or two.

Mike-VA3MW · June 15

the most common things are:

Time is off by more than 2.5 seconds - the one sample I saw looked ok
PC is slow, and your DT times are long - look at the DT column in WSJT or JTDX. It should be less than 1 second - again, likely ok
Your WSJT Bandwidth is too narrow. Look in the waterfall and set your bins/pixel to at least 5. By default it is 2 and you won't receive the entire bandwidth. The waterfall looked ok

Nothing here looks like a radio issue.

Erik Carling EI4KF · June 15

I should have seen that. You are decoding 2200Hz of the 3000hz band width. As Mike says extend out the bandwidth within the same size of Wide Graph window. That 8 or so station loss in my test will be stations between 2200Hz and 3000Hz, that are in SSDR but not in the FT8 software. Thanks Mike!

Mine is 3000Hz with Bins/Pixel =2 and the correct figure for you will depend on screen size and resolution.

If you are on a 4K monitor and have issues with Wide Graph size, try this: go to the properties of the jtdx.exe (or wsjtx.exe) and set High DPI scaling to Override by System.