r820t\sdrsharp\dsd1.6

[moonbounce]

Just wondering if anyone has been able to use all three to decode AP 25 with any success. I was think I will need two sound cards and probably up my RAM, but before I go and buy the card and RAM I just want to know if anyone has the same setup so that I know it is possible to do.

Moonbounce

 

[mtindor]

Just wondering if anyone has been able to use all three to decode AP 25 with any success. I was think I will need two sound cards and probably up my RAM, but before I go and buy the card and RAM I just want to know if anyone has the same setup so that I know it is possible to do.

Moonbounce

It's certainly possible. However, RAM isn't nearly as important as CPU. A multicore hyperthreading processor is needed for best results, although single-core CPUs of reasonable horsepower may yield okay results.

Bigger picture is getting your settings right in your SDR software. I can't tell you how to do that. Every SDR package is different. I'd recommending using SDRSharp with the Filter box UNchecked.

With decent CPU power and proper audio settings, you should be able to decode P25, DMR, NXDN just fine.

Mike

 

[moonbounce]

Well I have intel dual core 3.20 ghz with 2GB of DDR3 ram and Windows7 Pro, I think that should do the job.
I am thinking that SDR Sharp would have to be routed from the speaker output of one sound card into line in on a second card where dsd would decode AP 25 and send it out to the speakers?
You Tube has videos of a lot of people who have done it but they are short on instructions on how to do it. I guess I will just plug away.

Moonbounce

 

[mtindor]

Well I have intel dual core 3.20 ghz with 2GB of DDR3 ram and Windows7 Pro, I think that should do the job.
I am thinking that SDR Sharp would have to be routed from the speaker output of one sound card into line in on a second card where dsd would decode AP 25 and send it out to the speakers?
You Tube has videos of a lot of people who have done it but they are short on instructions on how to do it. I guess I will just plug away.

Moonbounce

You can use a program like Virtual Audio Cable (VAC) as the go-between without having to use multiple sound cards and have cables flying all over.

Dongle --> SDR Sharp ---> VAC --> DSD

So you would install VAC. Then in SDRSharp you'd set the output device to Line 1 (Virtual Audio Cable).

Then you'd set Line 1 (Virtual Audio Cable) as the default input device in Windows.

Virtual Audio Cable is the key to doing this with minimal hassle. Of course, it adds a little resource load to the system.

If you get all of that running to where audio is definitely feeding into DSD but you aren't making much sense of the decode, you should open up your task manager and watch the CPU usage while a P25 decode is happening. If it's spiking 100% CPU during P25 decode, then you've got a CPU bottleneck. The only solution for that would be more cowbell.

Mike

 

[moonbounce]

Thanks Mike

Right now my CPU with SDRSharp or DSD running is anywhere from 19 to 39% so I think the CPU should be up to the task. Also the security I have running on my computer doesn't like the VAC software that I am trying to download, so I think I might have to go with another sound card. So one question, would a sound card ease any resource problems if I should run into high CPU usage once I have the two programs running? Right now I can't tell as I can only run DSD or SDR but not both together, thanks.

Moonbounce

You can use a program like Virtual Audio Cable (VAC) as the go-between without having to use multiple sound cards and have cables flying all over.

Dongle --> SDR Sharp ---> VAC --> DSD

So you would install VAC. Then in SDRSharp you'd set the output device to Line 1 (Virtual Audio Cable).

Then you'd set Line 1 (Virtual Audio Cable) as the default input device in Windows.

Virtual Audio Cable is the key to doing this with minimal hassle. Of course, it adds a little resource load to the system.

If you get all of that running to where audio is definitely feeding into DSD but you aren't making much sense of the decode, you should open up your task manager and watch the CPU usage while a P25 decode is happening. If it's spiking 100% CPU during P25 decode, then you've got a CPU bottleneck. The only solution for that would be more cowbell.

Mike

 

[mtindor]

A second sound card would only remove any resource usage that VAC would normally consume, and that really isn't much. VAC doesn't consume nearly as much as either SDR software or DSD would consume. Good luck with the multiple sound card approach.

Mike