Spartanman
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Hi, im trying to decode a TierIII with DSD Plus but im not getting a good signal. I get the following data and errors. Could someone help me decoding the dignal (if its posible).
DSD Plus TierIII
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Describe your complete setup:
1. type of SDR
2. what if any SDR software you are running
3. how are you piping the audio to DSDPlus
4. Show the waterfall so we can see what the signal looks like (signal to noise ratio) and the filter width.
I can make some guesses based upon your screenshot, but if you really want help you need to be forthcoming with all of the relevant info
1. type of SDR
2. what if any SDR software you are running
3. how are you piping the audio to DSDPlus
4. Show the waterfall so we can see what the signal looks like (signal to noise ratio) and the filter width.
I can make some guesses based upon your screenshot, but if you really want help you need to be forthcoming with all of the relevant info
Spartanman
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Im using a RTL-SDR V3. With airspy. The audio is going to DSD Plus with virtual cable.
I should know the answer to this, but does the free version even handle DMR Tier III? I'm not sure DMR TierIII was even around when the free version was created.
Open your Audio window in SDRSharp and make sure that "Filter Audio" is unchecked.
And, although I should know the answer to this I do not -- does the free version from the website even handle DMR Tier III? I'm not sure DMR TierIII was even out when the free version was created.
And, compare the signal to the noise. You have your gain all the way up and likely do not need to have it all the way up. Slide your gain down little by little until your SNR (signal to noise) ratio worsens. Then boost the gain back up a notch. Your best performance would not normally be at max gain.
Open your Audio window in SDRSharp and make sure that "Filter Audio" is unchecked.
And, although I should know the answer to this I do not -- does the free version from the website even handle DMR Tier III? I'm not sure DMR TierIII was even out when the free version was created.
And, compare the signal to the noise. You have your gain all the way up and likely do not need to have it all the way up. Slide your gain down little by little until your SNR (signal to noise) ratio worsens. Then boost the gain back up a notch. Your best performance would not normally be at max gain.
Spartanman
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I have already unchecked. I somethimes get this: (NXDN96 CB DATA) and somethimes the same but voice. I dont hear nothing.
Spartanman
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And somethimes this too
You won't hear voice unless there is a voice call occurring, and it is not very likely that you will hear a voice call on a TIII control channel. Most TIII Control channels have both slots dedicated to control/data. But maybe you are lucky.
If you are seeing references to NXDN, it might be just because of a bad decode or maybe there is also an NXDN signal present on the same frequency and mixing with the DMR signal and causing interference. With 20db+ of SNR you should get a decent enough code for clean DMR.
Try the a more standard sample rate to see if decode improves. 1.8 should be fine, but it's an odd one. Set the sample rate to what the dongle allows by default (which I think would be 2.4).
If you are seeing references to NXDN, it might be just because of a bad decode or maybe there is also an NXDN signal present on the same frequency and mixing with the DMR signal and causing interference. With 20db+ of SNR you should get a decent enough code for clean DMR.
Try the a more standard sample rate to see if decode improves. 1.8 should be fine, but it's an odd one. Set the sample rate to what the dongle allows by default (which I think would be 2.4).
CC indicates it's a control channel.
The ? for channel is because it hasn't determined the LSN or LCN (and probably never will unless there is an actual DMR voice transmission on timeslot 2).
But you clearly need to decode the signal better, and I'm not sure what to tell you since you look like you have a decent enough SNR and your Bandwidth setting is okay and you claim "Filter Audio" is off.
You might be feeding too much or too little audio into DSDPlus from SDRSharp. Raise and lower your SDRSharp volume a little at a time and see if decodes get better or worse. If the incoming audio is too "hot" it's going to clip the signal.
The ? for channel is because it hasn't determined the LSN or LCN (and probably never will unless there is an actual DMR voice transmission on timeslot 2).
But you clearly need to decode the signal better, and I'm not sure what to tell you since you look like you have a decent enough SNR and your Bandwidth setting is okay and you claim "Filter Audio" is off.
You might be feeding too much or too little audio into DSDPlus from SDRSharp. Raise and lower your SDRSharp volume a little at a time and see if decodes get better or worse. If the incoming audio is too "hot" it's going to clip the signal.
Umm, in this screenshot, in the Audio window you DO have "Filter Audio" checked. I see it. I told you that Filter Audio CAN NOT be checked if you want a good decode.
Spartanman
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I have unchecked hahaha. I move the audio but the signal dosnt change. What audio do you mean¿?
I meant the audio slider in SDRSharp. Increase audio a little bit, then decrease audio a little bit. See if you get a better decode with more or less audio being fed from SDRSharp.
That's all I got. Somebody else will have to help you from here.
Spartanman
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Roger! Thaks for your help! Have a goooood dayy!
(I wait for new answers)
Ubbe
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You can reduce the bandwidth. When you receive a signal you drag the edge of the bandwidth in the spectrum display to just cover the received signal and nothing outside of it. It is the red and orange part you should cover and nothing of the yellow.
If the adjustment are unsymmetrical, it cuts into the red at one side but are still in the yellow at the other side, then go into the cogwheel setting and adjust the ppm until it is symmetrical.
I don't use that late version of SDR# but in the older versions you can hold the mouse pointer over the signal and it will tell you the signal/noise relationship, you should have as high value as possible and you might get that with a lower gain setting. It looks as if the signal are just 10dB above the noise floor, so pretty low and too much noise to be decoded properly. Maybe you can do something with the antenna, just moving it slightly might change the reception considerably, or use a FM broadcast filter.
/Ubbe
If the adjustment are unsymmetrical, it cuts into the red at one side but are still in the yellow at the other side, then go into the cogwheel setting and adjust the ppm until it is symmetrical.
I don't use that late version of SDR# but in the older versions you can hold the mouse pointer over the signal and it will tell you the signal/noise relationship, you should have as high value as possible and you might get that with a lower gain setting. It looks as if the signal are just 10dB above the noise floor, so pretty low and too much noise to be decoded properly. Maybe you can do something with the antenna, just moving it slightly might change the reception considerably, or use a FM broadcast filter.
/Ubbe
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