Help Decoding Digital Modes (Using FLDigi)

[Murphy625]

But if I go to USB, I can't even hear the signal at all.. the frequency just goes completely silent with nothing but static.
Not knowing what I'm doing, I was making a habit of finding a signal, then checking AM,FM,CW,RTTY,USB and LSB to see where its at.
I kind of quit doing it after a while because they're never on anything but LSB and occasionally the CW setting seems to work.

Now I'm confused.

 

[AK9R]

Leave the radio in USB no matter the band. If changing to USB causes the signal to disappear, tune around a little. You'll find it. The issue is that with some modes, the sideband is important. You may be tuned in to a signal using LSB, but fldigi may not be able to decode it because it's expecting a USB signal.

 

[Murphy625]

Leave the radio in USB no matter the band. If changing to USB causes the signal to disappear, tune around a little. You'll find it. The issue is that with some modes, the sideband is important. You may be tuned in to a signal using LSB, but fldigi may not be able to decode it because it's expecting a USB signal.

I trust what you're saying.. all part of my learning curve.. so I'm sticking to USB now and just ignoring the LSB even if it sounds clearer.

I uploaded an MP3 file in zip format.. they sure don't give you much space for files here!

I found this on 14.075 mhz USB just a few minutes ago ( 1:31pm EST ) but have heard this exact signal on the 40 meter band later at night. (See zip file to find MP3) I had to do a bit of converting to compress it down small enough for this forum.

I've tried tuning around, chaning SSB, applying filters and various decoding modes without luck..

I've noticed that a lot of decoding modes that start with the letter "M" means Music and that's the variable tones pitches I'm hearing.

Any ideas on what this is? It seems to be constant all day but found on different bands. And at night, when I hear it on 40 meters, I think its a conversation because I hear the same "music" at two different pitches on the same frequency.

 

[rescue161]

That is FT8. There really isn't much to decode other than grid squares and callsigns. If you are wanting to decode conversations, stick with PSK-31/63, RTTY, Olivia, etc.

 

[Murphy625]

That is FT8. There really isn't much to decode other than grid squares and callsigns. If you are wanting to decode conversations, stick with PSK-31/63, RTTY, Olivia, etc.

Well thank you very much! None of my software will decode it, which goes a long way understanding my problem.

Seems that the WSJT software will so I'll be using that this evening.

Thanks!

 

[rescue161]

For some reason, FT8 has taken off and everyone is using it. I don't see the fascination with the mode as it is only a quick handshake and you're off to the next contact. It's too automated for me. If you're using FLDigi, then stick to 14.070 or 7.070 and put the mode on PSK31. There are usually always some of those. That way, you can ensure that you're decoding. I like DM780 better as there were some modes I could not get to work properly with FLDigi. Plus I think the gui looks better on DM780 than it does on FLDigi. It was a lot easier to see the waterfall and signals using DM780. DM780 is part of HRD. You can download it for free and you can run DM780 as a stand-alone program without HRD.

Also, you may or may not hear the signal and you may just see a faint trace on the waterfall, but it should decode. You may have to play with the soundcard settings to get good decode, but once you do, it'll be easier to decode other modes.

 

[Murphy625]

For some reason, FT8 has taken off and everyone is using it. I don't see the fascination with the mode as it is only a quick handshake and you're off to the next contact. It's too automated for me. If you're using FLDigi, then stick to 14.070 or 7.070 and put the mode on PSK31. There are usually always some of those. That way, you can ensure that you're decoding. I like DM780 better as there were some modes I could not get to work properly with FLDigi. Plus I think the gui looks better on DM780 than it does on FLDigi. It was a lot easier to see the waterfall and signals using DM780. DM780 is part of HRD. You can download it for free and you can run DM780 as a stand-alone program without HRD.

Also, you may or may not hear the signal and you may just see a faint trace on the waterfall, but it should decode. You may have to play with the soundcard settings to get good decode, but once you do, it'll be easier to decode other modes.

For me, I don't just want to decode so I can listen in, I want to learn how to recognize and decode all the signals and become proficient at recognizing them and then decoding them... Just one more skill set to tuck under my belt for fun. I love learning new things like this.

Thanks a lot for your help.. being that FT8 isn't in any of my software, I would have grown old before I figured out how to decode it.

 

[rescue161]

Understood. It is very addicting, especially making contacts using very little power. I made some PSK31 contacts from NC to Indonesia using 5 Watts! Olivia is my favorite. It works even when you can't see it in the waterfall. Very weak signals can still be decoded 100%.

Usually the digital modes can be heard between .070 and .082. They are elsewhere, but I use FT8 as a good reference (as they are ALWAYS on). If I turn the radio on 7.075 and don't hear FT8 data, then I know the band isn't open for my location. It's a real good indication for band conditions and is a quick reference to see if the 10M portion is open. I quickly scroll through all of the bands to see which is the strongest and then use the strongest one.

 

[Murphy625]

Well I downloaded the wjft software and ran it this evening. The longer wave lengths were just horrible from the get go... lots of noise, very few people on the 80 or 40 meter bands.

I was able to find that signal again on 7.07x something.. fired up the wjft and set it for FT8 and got nothing. Went to the help file, spent a while reading and checking settings, and still nothing. I was on the USB this time.

I checked all the modes and the only one that got anything was the QRA64. I was able to get the message window to display the time, db, and bla bla bla.. but the message field was just "*" and that was it.
The waterfall lined up with the little green signal selector "U" (same width), but I still wasn't able to get any messages.
There was a lot of noise and none of my attempts to filter it did anything remarkable.

I'll try again tomorrow, hopefully the receiving conditions will be better.

Thanks again for your help, I'll update after my next attempt..

 

[Murphy625]

Not being able to let the dog sleep, I decided to give the 40 meter band a go this morning... wasn't really expecting much but I found that FT8 signal again..
So while the software was working, I decided to google a bit for more information and found a link somewhere that the PC's clock needs to be accurate.. I'm thinking, HUH? What the heck would that matter? But I was desperate so I downloaded a special window's app that keeps it on time.. as it turned out, because the laptop I use is only for ham use, I don't pull it out of storage often and the clock was an hour ahead.. (Daylight savings thing).

Oh man.. as soon as I updated that clock, the messages in the WJFT software started pouring in faster than I could click on them.
I knew this was going to be a newbie mistake thing..

 

[rescue161]

FT8 relies heavily on the correct time as it transmits for a certain amount of time, then it receives. With PSK31, or most of the other modes, the time is not important.

 

[Murphy625]

FT8 relies heavily on the correct time as it transmits for a certain amount of time, then it receives. With PSK31, or most of the other modes, the time is not important.

Ya, I got that.. and it only took me two days to figure that out! LOL

What a newbie mistake eh?

Now I have to patiently wait for a suitable 12vdc / 20amp power supply to pop up on craigslist for a reasonable price.