I have been mostly working JT modes since getting my Flex a couple of months ago. I have been using WSJT-X 1.3. Tx and Rx filters set 0-4000Hz.
It had always puzzled me that I had never decoded a JT9 signal when in JT65 + JT9 mode. A few days ago I saw a stonkingly strong (to use an English colloquialism) JT9 signal and still did not decode it.
After running some tests, I can only seem to decode JT9 signals when WSJT-X is in JT9 exclusive mode and my receive bandwidth is reduced to 2KHz and placed in the JT9 sub-band.
The signal I mentioned above got a signal report of +1 when I managed to decode it. The DAX Rx levels and those in WSJT-X were not changed at all during my tests.
What am I doing wrong? At the moment I don't know if this is related to WSJT-X or the way I have got the Flex set up.
You should definitely set your receive and transmit bandwidth to 4000 Hz or greater (I use 4200 Hz) as Larry suggests above. Use DIGU as that bypasses any audio processing such as equalization that you do not want for the digital modes. Also, check the location of the blue vertical line on the "Graph". The JT9 decoder is only active above the frequency indicated by this line. I normally set mine at 2500 Hz unless I see a signal that I want to decode at a lower frequency.
I do not think you have a Flex problem.
All is set present and correct as suggested by all of you above.
The blue separator line in the graph is set to the default 2500.
Tx width is 0-4000Hz
Rx filter width is 0-4000Hz.
These have been my settings since I first started and are not recent changes at all.
I am about to try the 1.4 RC2 release as I have heard that the decoders are significantly improved but I would like to get this issue nailed first.
OT bit - Not that I think it is related, but as I have the experts on board, do you chaps recommend AGC on or off?
Most of the time, I don't even bother with DIGU and run USB because it makes it marginally easier to get that bandwidth high enough.
Maybe I don't run it enough and should be stricter on my experiments to get better results, but I've been spoiled (lulled to sleep?) about how easy it has been. I always run with AGC set to fast and then (on WSJT-X) I set the gain to a value usually much lower than I do "by ear". Basically, when I see the "bar" on the main WSJT display fluctuate a little bit, near the top, it usually decodes pretty optimally for me as far as I can tell.
That said, JT9 is probably a more difficult mode, being darn close to being a carrier, so getting the modulation to "happen" is particularly critical. I usually run even less power with JT9 on transmit because I find my fans come on quicker with it than anything else I run and even that is well below the usual 1/2 power of standard RTTY.
But, if I'm having problem decoding JT9 signals, I sure don't know about it.
When I first started out, I had the bar at the top as you said Larry, but then I read that the best s/n ratio was for it to be in the middle with the slider close to the mid point. Either way, no JT9 decoded in mixed mode over two solid months' use. I'll test this again as I could have misread the manual.
Talking about the fans, the Flex 6x00 series is rated at full power for 100% duty cycle modes. I usually stick to 30W with JTx modes and rarely the extra fans kick in - surprisingly noisy but not intrusive. Hope they do not kick in much using SSB.
Guy, I've been playing with this as I have an intermittent decode problem with JT-9 at times when using the combined decode modes. I too have proven to myself the bandwidth setting is not the real issue.
However, I've seemed to make some progress on playing with the Rx amplitude slider on the lower left of WSJT-X while also playing with the AGC slider in the slice receiver. I seem to get more consistent JT-9 decodes with the WSJT-X receive amplitude is set around 20 as compared to 30 (the recommended setting).
Ed - NZ1Q
I wonder if the underlying setup ahead of the radio matters. For instance, I am blessed with a crank up tower whose height varies from approximately 55 to 65 feet (depending on where I left it) and substantial gain in nearly _any_ direction over many lower mounted antennas simply as a function of height. That doesn't count the cases where the beam is favorably pointed. My location is quite rural, so I have a decent setup in terms of local noise as well. Maybe that explains my relative success where I don't have to care much about the various settings and can decode both JT65 and JT9 without a lot of fuss.
I do play with the ACG slider on the Flex, but I haven't fussed with WSJT-X's amplitude at all. Maybe I should; perhaps my own results will go from "decoding" to "decoding more". Currently, I just set it so that I see "some movement" near the top of the vertical bar on the left. That seems to lead to better decoding. For me, it appears to be enough.
2. Set the Slice Passband to 5.1kHz. This will cause the radio to optimize for digital modes with lower latency.
3. If you set the filter > 5.1kHz, it's not necessary to uncheck the "FLATTEN" in WSJT-X. You will need to uncheck if you want to run a narrow filter. Here is a note from "JT" himself regarding FLATTEN:
> If you’re a TS-590S owner you may be interested in knowing that whenFor those who'd like to know what is going on:
> I first used the new Flatten option I observed a severe distortion
> of the waterfall. I had the bandwidth was set to 100–4000 Hz, which
> worked perfectly with the old Slope control.
The *Slope* control allowed the user to apply a straight-line
("straight" in dB) adjustment to the passband shape. The correct slope
had to be determined by trial-and-error.
The *Flatten* algorithm automatically fits and removes a second-order
polynomial to the lower envelope of the averaged spectrum. The active
region for this fitting presently extends from 200 Hz above the lowest
displayed frequency to the highest displayed frequency. If your filter
cuts off well above 200 Hz, or well below the highest displayed
frequency, *Flatten* (in its present form) will cause the "distortion"
You have two possible solutions: use wider filter in your receiver, or
reduce the highest displayed frequency in your waterfall. YOu can do
this by reducing Bins/Pixel or reducing the width of the Wide Graph.
> At first I thought Flatten was useless, but changed my mind whenWhat's the disadvantage in using the wide filter? With my TS-2000, I do
> I increased the DSP high cut to 5000 Hz. When I did that, the
> waterfall became perfectly flat (and I do mean flat) with no signs
> of distortion. Wonderful, wonderful, wonderful.
> The only problem with using Flatten with the 590S is that I can’t
> narrow up the bandwidth or use the radio's Data filter without
> encountering distortion. If I deselect Flatten, the Waterfall
> baseline drops and disappears. I need to do a considerable amount
> of tweaking of the Zero and Gain controls to produce a useful but
> not ideal Waterfall. Also, by deselecting Flatten there’s no way
> to flatten the response unless I change the 590’s RX audio response.
> For me, deselecting Flatten is NOT an option.
> If this were a perfect world, I would have the option of selecting
> either Slope or Flatten. But until then, its 100–5000 Hz forever.
almost exactly what you are doing. (I use Lo Cut=200, Hi Cut=5000 Hz.)
Unless you have an extremely strong signal in the 4000-5000 Hz range
-- enough to cause Rx blocking or undesirable AGC pumping -- WSJT-X will
just filter that range out, and you'll never know anything was there.
Finally -- it's surely possible to do a better job with the *Flatten*
algorithm. I just made it work well with my system, with a few
different test filter widths. If you have a system in which it does not
seem to work well, send me a *.wav file and your wsjtx.ini file as an
example. Ideally your example *.wav file should have only a few (or no)
-- 73, Joe, K1JT
4. Set AGC-T to 45-50 and use SLOW. You can adjust the level if you need to. I suspect you'll have plenty of excess gain to play with.
5. Use the DAX Control panel RX slider and the WSJT-X slider to set the RX level in WSJT-X to about -30dB with NO SIGNALS present. The best thing to do is try to catch the quiet period at the end of each minute. Joe's manual suggests that you try to keep his slider as close to center as possible. I bumped it down some so I could keep the DAX slider sort of in the middle as well.
6. For JT9 transmit, you'll need to set the TX BANDWIDTH "HIGH CUT" to 4.5kHz or so. It's a very sharp cutoff above that.
Once we got everything set well, we've had excellent results pulling signals out of the deep noise. Please try some/all/none of the above and give feedback on what works and doesn't.
73, Greg - K5GJ