SDR-Radio V2 discriminator audio output

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Markb

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After reading Scott's "Maximum Overdrive" thread, I tried the official trick of using FM-Wide and the 12.5 kHz filter and am not having any success decoding. I am using VAC (paid version). I have what sounds like wideband, discriminator audio, i see a waveform on UT's oscilloscope, but it looks a little flat. It shows about 20% decoding accuracy but no decoding whatsoever. Anyone have any ideas? Same problem whether P25 or 3600 SmartZone. No luck with DSD+ either.
Also, using the same VAC and same UniTrunker settings, I can run HDSDR which works great.

TIA,
Mark

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br0adband

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I've noticed similar activity myself using SDR-Radio (gotta love that recursive acronym style name) and the fact that the output from SDR-Radio is very low when FM Wide is chosen as the demodulation type; increasing all the volume controls in the path from start to finish don't help do much of anything in terms of the decoding performance either. I get a lot of decode errors of all kinds regardless of what protocol is in use (P25, DMR/MOTOTRBO, NXDN, etc) with SDR-Radio that I don't get using SDR# for the same purpose tuned to the same frequency and passing the baseband along to DSD+.

Maybe it has something to do with audio levels for FM Wide, I have no idea, all I know is that I don't even bother at this point using SDR-Radio for any digital mode monitoring whatsoever since (in my experience of using it) there's just something going on somewhere that wrecks the signal before it gets to DSD+, again at least for me.

When I fire up SDR# and DSD+ and hit Play, wham, near-perfect decodes of any protocol I'm capable of tuning in, period. Also, SDR-Radio seems to reverse the polarity of most every signal I try to decode with it; systems that I know for a fact are negative (-P25, -DMR, etc) that have zero issues with SDR# + DSD+ always end up being detected as the opposite if fed from SDR-Radio.

I like the program, I really do, and it does "sound better" than SDR# does by default, perhaps the reason it sounds better is part of the problem - there appears to be a lot of filtering going on that doesn't immediately appear to be anything we can totally disable to get a more pure (for lack of a better term) baseband signal for passing to DSD+ or DSD for the digital stuff.
 
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Forts

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But... who cares if the polarity is reversed? If it decodes, then hi-5's all around. I'm really not sure how the whole polarity thing works but I do know it has nothing to do with the setup of the actual system. It's not like there is a setting for a TRBO repeater where you select + or - polarity.
 

Markb

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I spent a few minutes before work this morning messing with VB cable and it did not make a difference. The fact is that if SDR-Radio works for one person, it *should* work for others, hardware differences aside.
I am not ready to throw in the towel just yet, The multiple VFO option is huge, so it would be a huge bummer if it doesn't end up working.

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Markb

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Been there, done that. Unless there is some nuance that I am missing. SDR-Radio is sending audio to Unitrunker, the VFO is tuned dead-center with 12kHz filtering and set to FMw.


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KC1UA

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It's a pretty cut and dried procedure. But....I think we have to take into consideration different sound devices, different PC's, different OS's,etc. and all of the side effects that can be caused by any combination of them.

That said, on three separate PC's, two of which run Windows 8.1 64 bit and one that runs Windows 7 Pro 64 bit, I have not had one bit of an issue using this method. And SDR# works fine as well.

Check recording device sound levels, make sure they're at 48000 Hz and not 44100, etc.
 

Markb

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Well, I tried it today and got it to work on an older, slower laptop. I can only run 2 VFO's and 2 instances of UniTrunker. Any more and the audio gets choppy. I'll have to mess around with the original laptop some more. Hopefully it's something with the soundcard settings. Otherwise it may be time for a new desktop. :)

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Markb

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PROBLEM SOLVED!!!!

After many sleepless nights, I realized what the problem was. I had the EQ active, so SDR Console was not in fact sending raw audio. Once I turned the EQ off, I was off and running. I had been using the EQ for HF monitoring with my Afedri Net-SDR.
I hope this is helpful for someone who is experiencing the same problem.

Back to decoding........

Mark

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