low performance on p25 with DSD

[germerc]

I am using a pro 2006 scanner for my dsd project. I tapped at the discriminator point adding a 10k resistor then ran a coax to the back of the radio to a 1/8 jack. I set my mic in level for my computer around 5. (it is a "mic in" and not a "line in".)

Ihave a few repeaters and a 800 trunking system that i have put into a scan list for the scanner. the software dose not register at all when a further repeater keys the scanner but when I get traffic from my local trunking sytemand more local repeaters i get bits and pieces of audio. the pieces of audio that do end up comming through sound good but audio at all is very spoty.

i am open to any and all opinions as to how I can inprove my set up!

thank you

 

[moonbounce]

I am using a pro 2006 scanner for my dsd project. I tapped at the discriminator point adding a 10k resistor then ran a coax to the back of the radio to a 1/8 jack. I set my mic in level for my computer around 5. (it is a "mic in" and not a "line in".)

Ihave a few repeaters and a 800 trunking system that i have put into a scan list for the scanner. the software dose not register at all when a further repeater keys the scanner but when I get traffic from my local trunking sytemand more local repeaters i get bits and pieces of audio. the pieces of audio that do end up comming through sound good but audio at all is very spoty.

i am open to any and all opinions as to how I can inprove my set up!

thank you

Thanks for posting that info. I run DSD on an old Pro 20/20 with the same results, I was thinking of switching radios and trying my Pro 2006 but now I don't have (to thanks to you), as it sounds like I will have the same results as before. SSOOOO, if using a pro 20/20 or a pro2006 gives the same results, what about the computer.

I had been thinking that maybe my computer was at fault, maybe I need to upgrade my RAM, or sound card or processor. I currently have an Intel e5800 processor with 2G of DDR3 ram, that seems to be good enough to run anything I use the computer for, I don't know why DSD would be any different. Maybe I just have to settle with what I have? I have also tried many different tweaks with the same results, so I am at a loss to figuring out a way to make the sound quality better.

Moonbounce

 

[mtindor]

1. Processor is key [in my book] -- need a multicore hyperthreading processor of decent speed. Some machines are multicore (E5800 is 2 cores), but dual cores doesn't necessarily mean hyperthreading [E5800 isn't hyperthreading].

Various decoding software may rely upon both multiple cores and hyperthreading to achieve the best result.

2. When actively decoding P25 or DMR, you should have your task manager open and should view processor usage to see if it's spiking to 100% during decodes. My T5750 Core 2 Duo and my Pentium D HT 2.8 did.

3. Make sure you're using the latest available DSD4win (what many people call the Windows version of DSD) -- currently 1.6

4. Try to get your INLVL (as shown in DSD when it's decoding) to somewhere around 25-30%. At least that seems to be the sweet spot for me. If my INLVL is 25-35% I don't touch it. If it's higher or lower, I adjust the recording (input) audio level until DSD shows between 25-30 INLVL.

5. I don't know anything about the audio levels coming out of 2006 and 20/20 scanners with 10k resistors inline. I'd think it should be adequate. I think there are only certain scanners that are too hot on the incoming audio and need tamed.

Mike

 

[moonbounce]

Thanks Mike, my CPU usage in the task manager when DSD is active (apco25) runs anywhere from 5% to 27% with the odd spike to 37%, nlvl is 29 to 32%. The processors while not having hyperthreading, is a dual core 3.20 Ghz processor.

I was wondering what anyone who is not having an issue with the quality of the sound coming out of DSD might be running for a processor?

 

[AZScanner]

I get pretty decent decodes out of my old POS Celeron laptop using an SDR dongle and SDR# to feed audio to DSD. It works much better than the tap on my old BC895 because of the ability to adjust the filter settings, bandwidth, audio latency, you name it. For $20 you can't go wrong. I highly recommend getting one of these RTL-SDR's and downloading SDR#. It takes a bit of work to figure it out and get it properly set up but the results are stellar once it's dialed in, even on older hardware.

As for a proper machine for decoding (and for doing other things) I recommend going out and spending a few extra bucks on a gaming machine. These PC's are designed for very CPU intensive tasks (such as today's 3D games) so running DSD should be a walk in the park for them. Amazon has some good deals right now on gaming PC's - I saw one for less than $700. Or if your savvy enough to build your own, you can build a high performance gaming rig yourself for $100-200 less than that. Bear in mind also that a good portion of that cost is for a high performance video card, so if you're NOT planning on playing Crysis 3 or anything like that, you can save yourself a couple hundred dollars there as well and build a high performance machine (minus the video card) for $300-$400.

-AZ

 

[mtindor]

Thanks Mike, my CPU usage in the task manager when DSD is active (apco25) runs anywhere from 5% to 27% with the odd spike to 37%, nlvl is 29 to 32%. The processors while not having hyperthreading, is a dual core 3.20 Ghz processor.

I was wondering what anyone who is not having an issue with the quality of the sound coming out of DSD might be running for a processor?

Sounds like you should be okay for process then. I guess it has to be the audio that is coming in from the tap. Using DSD 1.6, you really should get fairly decent decodes from even the most basic discriminator tap.

Mike

 

[mmisk]

DSD Marginal w/ Onboard Sound

I have been using DSD for quite some time now with excellent results. At the moment I am listening to provoice on an old Celeron and it works fine. However on my triple core computer, DSD was only marginal and that is using the on board sound. This weekend I finally installed an old sound card I had kicking around and now DSD is excellent. So for some reason DSD did not work all that well with the on board sound, don't know why.
Perhaps this will help you and no real cost is involved. And don't forget that a really solid signal is required for digital radio comms, or at least that is what I have observed over several years of listening to these signals.
Good luck!