WinRadio G33 - DDC playback?

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majoco

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A friend with a recently acquired G31 asked me about recording the DDC window which was something I had never done - recording the audio as a WAV file yes, OK, but not the DDC window. So I set up a schedule to record 100MHz of the 8MHz aero band 200kHz wide starting at 2300local 1100z. Now I have a file of 101MBits with the expected DDC files with a header or frequency, start time, and a few other bits of info, all looking good. Opening up "recording/playback" and browsing for the file, it's not there. It's there when looking for it with Explorer but not inside of Winradio. Do I need a playback plugin or what? The help screen and manual don't help much - tells me lots of things that I don't need but not what I do!

Any help gratefully received.
 

majoco

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I looked at Bjarne's blog about recording and playback. When I go into the playback section and go to
"Browse" I can find the file folder that I recorded it into, but there's only WAV files - no DDC's (software ver.2,05). If I change the file name to *.* it finds the DDC files and they show in the playback square but don't play!

I now know that a 100Mbit DDC file would result in a playback of....very little! Needs Gbits!
 
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Token

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I do DDC recordings with the G39, G35, G33, and G31 all the time. Files can get quite large, but it is great being able to play back recordings using different demod / filter settings. Just make sure you have some storage space, my main radio storage is a 24 TB NAS, and I also have 12 and 8 TB NAS's with radio recordings on them. The 12 TB is dedicated to oddity stations, the 8 TB to numbers stations.

The G33 can record I/Q data files in one of two formats, either DDC or RXW. There is no secret to playing back recorded DDC or RXW files. Just "Browse" to the location and select the file. Then press the Play button (sideways triangle). If you are not seeing the files when you browse in the Excalibur GUI, but you are seeing them in Windows Explorer, make sure you have selected the right file type in the Browse window.

If, in the Excalibur program, you browse to the right location and do not see the file you want, try the other extension, possibly you accidentally selected the wrong format. To look for the other format, in the Browse window, to the right of the "File Name" window there is another window, it will say either DDC or RXW, probably DDC. Select DDC (click on it) and pull down to RXW. Then see if your files show up.

T!
 

majoco

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Hi T!,

That pretty well sums up what I'm doing, but at the stage where I select my DDC file to be played back and it's not there, then clicking on "Files of type" looking for DDC or RXW, all I get is WAV or WWV. If I fool it by making "Files of type" *.* then it finds all the files, click on the DDC file and it gets transferred to the playback "File Path" but clicking on the "play' button does nothing.

I'll do some screen shots tomorrow so you can see what's going on.

In fact it's not worth getting up a real sweat about it, but it would be nice to get it to work.
 

majoco

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My friend with the G31 has said that he has it working well so it's my problem!

Attached is a screenshot of what happens when I click on "Browse" and open the drop-down for file type - all I get is a choice of WAV or WWV even though there are some DDC's in the folder. Also you will see that the main screen recording set up there is only the WAV setup even though I have clicked on insert FDT. The "File Path" is blank as I deleted it to see if it would find a new folder.

I'm thinking about composing an email to the WinRadio support desk in Aussie - but I need to experiment some more. I do recall that some time ago I tried unsuccessfully to get the VAC to work - I wonder if it's symptom of the same defect - the VAC works fine on my G303.
 
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Token

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OK, I may see what is going on here, if you are trying to find the DDC recordings as it looks in that picture. You are trying to replay DDC recordings in the Demodulator Record Facilities control. You must do it from the DDC Record Facilities control

In the DDC window select Spectrum display, not Waterfall:
165495742.4w6r20RU.jpg



While in Spectrum mode select the Red Triangle:
165495743.evXu2ZxR.jpg



You have now brought up the DDC Record Facilities control panel:
165495744.wzfVrpvH.jpg



You can now reselect Waterfall mode with the button in the upper left corner of the DDC window. You can also do manual DDC recordings, with manual start and stop. You can also set the Pre-Buffer size. If you have never used the Pre-Buffer you might like it. With, for example,a 3.0 second Pre-Buffer when you select the Manual start record button the recording goes back 3 seconds and start the recording then. So you can hear a signal start, hit record, and grab up to 3 seconds form before you hit the start record button.
165495753.h068vQPW.jpg




T!
 

majoco

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WinRadio G33 - DDC playback - fixed! Thanks Token.

Thanks Token, you've found the solution about the same time as I did!

I was led astray by this bit on page 77 of the User Manual...

Just a couple of misinterpreted words at the start of the recording section - "At the top of DDC and demodulator spectrum scopes there are special “red*triangle” buttons that serve to reveal their respective recording facilities.*" then it shows a pic of the audio spectrum display and it says "Pressing this button will reduce the height of the spectrum scope at the bottom
and utilize the extra space for the recorder controls."* Note "this button", not "these buttons", so I believed there to be only one button that did both functions!

So, if all else fails read the flaming manual and understand it!

Thanks for your help and work that you must have put in to this seemingly simple problem but had me tearing my hair out!

Cheers - Martin
 
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majoco

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Yay, it works! Last night I recorded 30 minutes of a 200kHz wide swath of the 8MHz aero band and it all works very well! About 3.5Gbits of storage space!

Thanks Token, Mike and all! - Martin
 

j_renner

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Hi I need help about G33;

Narrowband spectrum display corresponds to the DDC2 of G3xDDC SDR ?
and ddc1 for wideband recording ?

How the channels are related to these ddc1 and ddc2 while recording ?

How the unmodulated record(raw) can be captured ? I would like demodulate by another processing tools.

Did you every try or did you ever process your record in any processing program like octave or labview ?

Thx,
WR
 

majoco

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Narrowband spectrum display corresponds to the DDC2 of G3xDDC SDR ?
and ddc1 for wideband recording ?
The bandwidth you have selected on the demodulator screen width (the gray area) is indicated by the small gray line above the frequency on the waterfall/spectrum. Similarly what you see on the spectrum/waterfall full width is shown on the gray area on the full spectrum display.
How the channels are related to these ddc1 and ddc2 while recording ?
Don't understand "channels" - while recording what - audio?
How the unmodulated record(raw) can be captured ? I would like demodulate by another processing tools.
Unmodulated? - do you mean undemodulated? The audio recording is saved as a WAV file - most audio manipulation software will accept WAV files directly.

Reading through it all again, if you record the DDC2 screen, then you have to play it back through the receiver - then you can record the audio which comes as a WAV file and process that externally.
 
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j_renner

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The bandwidth you have selected on the demodulator screen width (the gray area) is indicated by the small gray line above the frequency on the waterfall/spectrum. Similarly what you see on the spectrum/waterfall full width is shown on the gray area on the full spectrum display.

Don't understand "channels" - while recording what - audio?

Sir, thank you so much for your quick response, I appreciated. As you know, g33 has three channels. While recording audio, if I chose ddc1 or ddc2, then step by step basically the relation of these three channels with ddc1 or ddc2. These three channel are divided within ddc1 and 2 ? What are the interactions of ddc's and channels in general while recording step by step?

Unmodulated? - do you mean undemodulated? The audio recording is saved as a WAV file - most audio manipulation software will accept WAV files directly.

Reading through it all again, if you record the DDC2 screen, then you have to play it back through the receiver - then you can record the audio which comes as a WAV file and process that externally.

Sir, does the receiver demodulate it by software after the record is completed ? For instance, The record can include any modulation technique, then how the receiver knows ? Therefore, I need raw(unprocessed) data to implement demodulation by another processing tool or do I need to demodulate ? I guess so...

Thx,
WR
 

majoco

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Hi Jeremy,

I have answered your questions here because any bit of info that gets read and understood by another reader may be of help to them as well - thanks for your email.

It would appear to me that your understanding of how the G33DDC works and what is being presented on the three screens is a little sketchy. I suggest you go to the very first entry in the "Software-defined-radio" forum and go through Tokens very informative Sticky post on the Winradio Excalibur.

Now, to hopefully answer your main question - you can only record audio from the "Demodulator Spectrum" window. The window shows the pre-demodulation spectrum so you can see the AM carrier and sidebands, the SSB sideband on it's own, the two tones of a fax transmission or PSK32 or whatever BUT you cannot record the pre-demodulation there. The form of demodulation is selected by you from the push-buttons along the top of the screen, AM right through to "User" (whatever that is.) It's not automatic, you have to determine what demodulator to use with the particular signal you have in the display - you will also have to fit the signal into the bandwidth ( the grayed out area) by adjustment of the pushbuttons or the "DEM BW" dropdown menu.

If you really want to record the RF signal then you have to go through the process that I had the problem with in all the previous posts under this heading. At the moment I haven't played with that much, and I haven' tried any method of using the saved signal and using an external demodulator to explore the data contained therein. You have to replay the recorded RF back through the receiver to observe, select the signal of interest and maybe re-record as audio. Your replayed file appears just as an off-the-air signal would, except you can play it as many times as you like and listen to individual signals that may have occurred simultaneously and record each audio separately.

Don't forget that there is a very good users guide in your 'documents and settings' folder that was downloaded with the software although it did lead me astray a bit as above! That's the problem with the writers of technical manuals - they know how to work the equipment down to the last button-push, but when it comes to writing it down and expecting a complete novice to understand it, there is something lacking!

MR. Moderator - if you feel that these few posts belong in a separate topic then feel free to move them.
 

majoco

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A PS...

I wonder if you are misunderstanding the three separate receivers that you can select from the pushbuttons top left of the screen - you can have any three frequencies selectable from these buttons and the highlighted one is updated from the current screen. However the cunning thing is if you have three frequencies within the current DDC bandwidth, then you can listen to all three at the same time and if you have stereo speakers connected then receiver 1 comes from the left, #2 from the centre and #3 from the right speaker! You can tell if you have it set up correctly, as all three will be white if correct and red if outside the DDC bandwidth. Either way its very handy for frequency-hopping!
 
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