AM audio spectrum display not symmetrical

All bug reports here please
jdow
Posts: 800
Joined: Mon Aug 10, 2020 8:17 pm

Re: AM audio spectrum display not symmetrical

#21

Unread post by jdow »

You are simply and comprehensively wrong. It may not be what is "right" as you see it. It may be confusing as you see it. It is displaying precisely what comes out of the demodulator. If turning on the 25 Hz HPF does not cure it perhaps the audio feed to the O'Scope could be changed appropriately. But, the DC bias is there. It is real. It is a required part of the demodulation process. And there is no way to remove it reliably and accurately without filtering. If you don't like that take it up with the creator about the "bad design" for the universe.

{^_^}

RadioSDR1
Posts: 59
Joined: Sun Jun 26, 2022 4:41 pm

Re: AM audio spectrum display not symmetrical

#22

Unread post by RadioSDR1 »

You say “It is displaying precisely what comes out of the demodulator” yet I said’ “What I have learned through this dialogue is that the DC bias from the AM carrier is being brought forward to the audio waveform” and I also said “The fact it can be filtered (mostly) out by the 25 Hz HPF in the equalizer function proves it is a problem. If all that is required to fix this is to filter it, then that filtering should be applied automatically behind the scenes in code pertaining to the AM function so then nobody needs to think about it.”

You say “But, the DC bias is there. It is real. It is a required part of the demodulation process.” I say that is a ‘straw man’ arguement because that statement is not germane to the substance of my last post and I am also not questioning the existence of DC bias or its presence as part of the demodulation process. What I am questioning is this software bug where DC Bias isn’t being filtered out before it gets into the audio and audio oscilloscope waveform.

Then you say “And there is no way to remove it reliably and accurately without filtering.” And I say to that, no kidding as this was the substance of my last post.

Are you gas lighting me on purpose for amusement? I don’t get it.

jdow
Posts: 800
Joined: Mon Aug 10, 2020 8:17 pm

Re: AM audio spectrum display not symmetrical

#23

Unread post by jdow »

When I read what you say you seem to agree with me and then suddenly say something the exact opposite that sounds like "But SDRC should fix it anyway." There are reasons to have the DC present on output sometimes and other times have it filtered. There is a filter selection. What more do you want? I do not see that there is a problem here.

Perhaps I misconstrued what you said. If so I am sorry.

{^_^}

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