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Shortwave Data Decoding - Discussions regarding decoding digital signals on the HF bands, including HFDL, ALE, RTTY, CW, and others.

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  #1 (permalink)  
Old 08-07-2018, 12:20 AM
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Default Multipsk help.

I installed MultiPSK onto my laptop. Unfortunately, my Panasonic Toughbook CF31 doesn't have any audio inputs or outputs! LOL .. Huh? That's strange..

But what it does have, and it works well, is bluetooth.. So I connected to the bluetooth ear piece I use for my cell phone and just set it on top of the speaker of the ICOM 746.

It seems to work well..

The MultiPSK picks up the morse code but I'm getting junk.. the "quality meter" goes from 2/5 to 3/5 but the letters its spitting out make no sense at all.

When the radio is just churning out static, I get all kinds of funky looking ASCII characters, but when I find a good morse code signal coming in, I can play with the filters and get it tuned in rather well and the quality will go to 2/5 or 3/5.. MultiPSK will then start spitting out what looks like random letters and numbers.. occasionally mixed in with an @ sign or a $ character.... but mostly letters and a number mixed in here and there.

Am I doing something wrong or is this encrypted stuff?
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Old 08-07-2018, 6:47 AM
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It's impossible to evaluate this without knowing precisely where you're tuning (frequencies, times...) but you can't completely depend on a program to decode CW at 100%. Different styles of sending, noise issues are all going to cause issues. Are you tuning in the ham bands for your CW attempts? They can never, ever be encrypted in any way.

If you are using a portable radio - generally they don't have filters that are narrow enough for reliable CW decoding - so the program is trying to decode everything in the passband. It's never going to work very well that way. What radio are you using?

You might also try some 'scheduled' digital broadcasts to verify that your bluetooth connection is actually working and not the source of your issues..I've never heard of a bluetooth connection working this way, but if you're hearing the audio through your laptop speakers, well, that's a first. See this article from our wiki for known scheduled stuff

Testing Your New Setup - The RadioReference Wiki

Finally MultiPSK has a dedicated forum for support. You can find it here...

https://groups.io/g/multipsk

I suspect you will need to use a USB driven sound card - I have the same issues here, using a Win10 laptop with no mic or line ins. That's they way I would go, frankly

Mike
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Old 08-07-2018, 11:55 AM
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Quote:
Originally Posted by ka3jjz View Post
It's impossible to evaluate this without knowing precisely where you're tuning (frequencies, times...) but you can't completely depend on a program to decode CW at 100%. Different styles of sending, noise issues are all going to cause issues. Are you tuning in the ham bands for your CW attempts? They can never, ever be encrypted in any way.

If you are using a portable radio - generally they don't have filters that are narrow enough for reliable CW decoding - so the program is trying to decode everything in the passband. It's never going to work very well that way. What radio are you using?

You might also try some 'scheduled' digital broadcasts to verify that your bluetooth connection is actually working and not the source of your issues..I've never heard of a bluetooth connection working this way, but if you're hearing the audio through your laptop speakers, well, that's a first. See this article from our wiki for known scheduled stuff

Testing Your New Setup - The RadioReference Wiki

Finally MultiPSK has a dedicated forum for support. You can find it here...

https://groups.io/g/multipsk

I suspect you will need to use a USB driven sound card - I have the same issues here, using a Win10 laptop with no mic or line ins. That's they way I would go, frankly

Mike
Thanks Mike,
I already ordered a USB sound card with line in, mic in, and several other ports.. they call it a 5.1 or something like that. Cost a grand total of $12 on ebay but I saw youtube video's saying it works.

One think I noticed on the wave form scope is that morse code has peaks that are far above the back ground noise.. Do these CW decoders (any?) have some sort of noise floor setting where you can get them to ignore the static? Sort of like a squelch for sound? I did notice that my MultiPSK had a line in the wave form readout and you're supposed to click the line and drag it to the wave peak so that it centers on the frequency.

I'll have to visit the MultiPSK forum.. Thanks for that!!
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Old 08-07-2018, 3:19 PM
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Quote:
Originally Posted by Murphy625 View Post
<snip>
One think I noticed on the wave form scope is that morse code has peaks that are far above the back ground noise.. Do these CW decoders (any?) have some sort of noise floor setting where you can get them to ignore the static? Sort of like a squelch for sound? </snip>
Not that I'm aware of, no. It's highly dependent on how your radio - and we still don't know what you are using, or where you are tuning - processes the audio. It's difficult to generalize without more facts.

Mike
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Old 08-07-2018, 5:02 PM
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I'm using an ICOM 746
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Old 08-07-2018, 5:08 PM
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I didn't get a chance to do this earlier, as I have to leave, but there's a couple of other things here;

a. That trash you see on the screen now may very well be slop from your PC getting into the audio chain and fooling MultiPSK into thinking it's real data.

b.Make sure you are using the dedicated CW mode and proper filters. Most programs want to hear a 800 hz tone for the CW- you may need to fiddle a little with it to make it work

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Old 08-07-2018, 6:06 PM
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FlDigi has a better CW decoder than MultiPsk and is fairly simple to use
but having both at the ready is a very big toolbox
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Old 08-07-2018, 8:04 PM
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Quote:
Originally Posted by k9wkj View Post
FlDigi has a better CW decoder than MultiPsk and is fairly simple to use
but having both at the ready is a very big toolbox
Ah yes, and better reviews.. Downloaded it, and the help files.. Will play around later.

Thanks!
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Old 08-08-2018, 6:42 PM
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Quote:
Originally Posted by Murphy625 View Post
Do these CW decoders (any?) have some sort of noise floor setting where you can get them to ignore the static? Sort of like a squelch for sound? I did notice that my MultiPSK had a line in the wave form readout and you're supposed to click the line and drag it to the wave peak so that it centers on the frequency.
I also use MultiPSK, and yes, there's a squelch setting when you use the CW mode. It's a slider located in the line just above the spectrum display.

Anyway, I've always found CW the hardest mode to decode. It works pretty well, however, if the signal is strong enough, there's hardly any fading and the person doing the keying isn't too sloppy. Some people leave too much space between each letter, so that there are no words, just single letters. Others don't leave enough space between words, causing their messages to come out in long, unbroken streams, which are nearly impossible to read, even if they've been properly decoded. Yet others send the dots real fast, but make their dashes too long. This doesn't decode at all.

The easiest CW to decode seems to be sent by KPH's operators, who have a good "fist". The trouble there is that KPH is only on the air on Saturdays, so you might have to make sure you're around on a Saturday to test your setup.

The other thing I've tried is one of the nondirectional beacons on longwave. The signals are automated and the audio is nice and clear, but of course all you'll see is two or three letter station IDs repeated at nauseum.

Last edited by GB46; 08-08-2018 at 6:54 PM..
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Old 08-08-2018, 6:48 PM
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While on the subject of MultiPSK and regarding the signal vs. the noise floor, one thing I've noticed is that during pauses in the transmission or during fades, the noise floor shown on the spectrum display goes way up, then works its way gradually down again when the signal returns. I thought I was seeing the effects of my receiver's AGC, so I shut the AGC off and turned down the RF gain a bit, but I was still seeing the same thing. I'm using my laptop's mike input and have made sure to disable the automatic gain control on that, but this makes no difference, either. I wonder if what I'm seeing is caused by the MultiPSK software; does it have its own form of AGC? I haven't seen any mention of it among the options.
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Old 08-08-2018, 10:37 PM
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So I downloaded CWDecoder.exe and ran it and it works great! Opened up both MultiPSK and CWDecoder and ran them side by side.

The MultiPSK spits out garbage while the CWDecoder spits out recognizable messages. I'm attributing some of the misspellings to the operators doing the thing they do when text messaging.. Like "im going 2 stor 4 milk" and "C U Tomorw"

I'm using an ICom746 with a dipole antenna that's only about 20 feet off the ground.. Going to raise it up soon.
My Panasonic Toughbook CF31 does not have audio ports but it does have bluetooth so I just paired the ear piece I use for my cell phone to the laptop and laid the ear piece on the Icom's speaker.. and it works! Seems to work well too.

I ordered one of these on ebay:
https://www.ebay.com/itm/6-Channel-5...sid=m570.l1313
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Old 08-16-2018, 5:18 PM
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Quote:
Originally Posted by Murphy625 View Post
Unfortunately, my Panasonic Toughbook CF31 doesn't have any audio inputs or outputs!
What are you talking about? The audio jacks are on the rear, left side of the unit.
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Old 08-17-2018, 2:56 PM
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What are you talking about? The audio jacks are on the rear, left side of the unit.
I looked all over my toughbook multiple times.. the only thing on the back panel was a slider door to access the port replicator and another door to access the serial port..

I had even asked the ebay seller and they said they didn't see any audio ports. So after your post, I got on google and found that the entire back side of the thing is one big giant 6 inch long door with the port replicator slide thingy built right into it.

Found the latched, popped it open, and immediately felt like an idiot.
It was the two little phillips head screws that made me think it wasn't a door.

I've always built my own computers from ground up.. even do some vba programming..

Wow.. I must be losing my computer super-geek powers in my old age.

What a brain fart..
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