You're not showing the System Evaluation display, so it's hard to tell what's going on. From what you are showing it looks as if there's not a good, clean signal there. You need to have about a 12dB signal-to-noise ratio for it to demodulate the audio properly. Given that you're only showing two bars at the top and two at the bottom (it won't play without all three on the bottom), I'd say that's what's happening. Plus, it looks like you have some serious in-band power interference on the GQRX display, making matters even worse.
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What may help is if you set the following in the System Evaluation window:
Misc Settings - MLC: Number of iterations: 4
Audio - Reverberation: Off (not really sure that will help, but won't hurt processing)
Interferer Rejection - Bandpass Filter: On
Interferer Rejection - Modified Metrics: On
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Hi!
I have tried as you suggested, but MSC CRC is always red, even when SNR is >14.
As a result no audio, I will try to get some shortwave DRM and update here.
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As a rule, you'll also want your receiver filter at least 10kHz wide and Sharp instead of Normal. You may also want to look at the local noise source that's creating in-band interference... Almost looks like mains or display noise, so you'll want to look at the antenna you're using.
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I have build Dream from https://github.com/godarklight/dream for Ubuntu 20.04
I am able to decode local DRM channels but playback is not working due to the following errors-
*** playback UNDERFLOW
fill failed 5
Can you please help me resolved this issue?
Last edit: Subhadip 2024-04-15
You're not showing the System Evaluation display, so it's hard to tell what's going on. From what you are showing it looks as if there's not a good, clean signal there. You need to have about a 12dB signal-to-noise ratio for it to demodulate the audio properly. Given that you're only showing two bars at the top and two at the bottom (it won't play without all three on the bottom), I'd say that's what's happening. Plus, it looks like you have some serious in-band power interference on the GQRX display, making matters even worse.
Thank you for the insight.
Looks like SNR is the root cause. I am attaching a screenshot of best SNR I could get for reference.
What may help is if you set the following in the System Evaluation window:
Misc Settings - MLC: Number of iterations: 4
Audio - Reverberation: Off (not really sure that will help, but won't hurt processing)
Interferer Rejection - Bandpass Filter: On
Interferer Rejection - Modified Metrics: On
Hi!
I have tried as you suggested, but MSC CRC is always red, even when SNR is >14.
As a result no audio, I will try to get some shortwave DRM and update here.
As a rule, you'll also want your receiver filter at least 10kHz wide and Sharp instead of Normal. You may also want to look at the local noise source that's creating in-band interference... Almost looks like mains or display noise, so you'll want to look at the antenna you're using.