SDR Issue - Appears to Decode, but No Audio

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seberry

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Hello everyone,

I seem to be having a bit of an issue with my setup. I'm attempting to monitor a p25 trunked system with SDR#, Virtual Audio Cable, UniTrunker, and DSD.

My problem is that everything appears to decode fine: I get a good green level in UniTrunker, and the DSD monitor window scrolls by continually. SDR# even trunks by flipping back and forth between the control channel and the voice channels. The only thing that's missing is the audio.

I've attached a screenshot for reference. Anyone have any ideas?

I have checked and verified that my default audio input and outputs are correct.

 

seberry

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Nov 8, 2010
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Colorado
Correction on my post - I have found that there is no problem with SDR itself - everything is working now, except scanning. I think that the antenna supplied with the dongle might be terrible because I can only get audio when tuning to a voice channel *ever so perfectly*, and even then it's not very good. Anyone have any tips, or is it time to find a new antenna?
 

BM82557

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Berkeley Co WV
I suggest you look into DSDPlus instead of DSD if for no other reason than the audio is much better. I never had much success with DSD myself. From your UniTrunker screen shot it looks like you have good signal strength.
 
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joeuser

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I'd like to add that you forget about SDR# & just use Unitrunker - it supports the RTL820 dongle natively & makes it much simpler to accomplish your goal

Sent from my Nokia Lumia 928 - Windows Phone 8.1 using Tapatalk
 
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Correction on my post - I have found that there is no problem with SDR itself - everything is working now, except scanning. I think that the antenna supplied with the dongle might be terrible because I can only get audio when tuning to a voice channel *ever so perfectly*, and even then it's not very good. Anyone have any tips, or is it time to find a new antenna?
The antenna seems fine seeing the green bars you're getting in Unitrunker. And if you're using the same dongle for the control channel and voice channels, and the green bars come back in Unitrunker after what should be a voice call is done, the only things I can think of are that 1) DSD is sending the audio to the wrong audio device (only DSD+ lets you select which one you want to use) or 2) encryption is being used.

If you have two separate dongles, make sure the one going to the voice channels is correctly calibrated. Zoom in on SDR# and make sure that when a voice call comes in, the tuner centers on the actual signal.
 
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