DSD and PSR-310

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alfonzo1955

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I am using my PSR-310 to track a Motorola Type II SmartZone system that contains both analog and APCO-25 digital. I am trying to decode the digital signal with DSD which has a feed from my tapped PSR-310. When I see a talkgroup that I know is digital, I don't get anything on DSD and nothing but weird noise (which is probably the digital) from my scanner. Can anyone help me?
 

SCPD

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The '310 does not follow ProVoice calls. You could scan the voice channels as conventional channels or purchase a second '310 to feed the Motorola control channel into Unitrunker while Unitrunker steers the first '310 to analog and IMBE calls. DSD would of course provide audio for the digital voice calls.
 
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SCPD

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The 310 can distinguish analog from digital calls as they're announced on the control channel. It's programmed to ignore the digital calls on a Motorola system. Otherwise you'd hear noise. If you've programmed the radio to scan the channels as conventional, it will work but you won't have much control over what you hear since you've given up filtering by talkgroup.
 

Mike_G_D

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The 310 can distinguish analog from digital calls as they're announced on the control channel. It's programmed to ignore the digital calls on a Motorola system. Otherwise you'd hear noise. If you've programmed the radio to scan the channels as conventional, it will work but you won't have much control over what you hear since you've given up filtering by talkgroup.
Hmm...not in my case. My 310 will track the digital talkgroups in the mixed mode Motorola system I monitor (San Diego County RCS) if I put them in. It's a problem when I load a file that was originally made for my 500 as I have to delete (or lock out) all of the digital talk groups or I will, of course, receive the raw P25 noise on those talk groups. In my case, I wish it would skip those talk groups as it would make the sharing of files between the 500 and the 310 easier.

-Mike
 

SCPD

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Hmm...not in my case. My 310 will track the digital talkgroups in the mixed mode Motorola system I monitor (San Diego County RCS) if I put them in.
The call type (digital vs. analog) is present only in the initial call grant. If you join a call already in progress, the radio won't know it's digital.
 

alfonzo1955

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Please, I still need help with this. I don't have the money to buy a digital scanner and I really want to listen to digital.
 

GTR8000

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kma371

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Thanks.

So what problem are you having with DSD? Have you tried inverting the signal?
 

GTR8000

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Is DSD decoding any voice for you? I would start at the basics and connect the tapped 310 to the soundcard, hold the scanner on a single voice channel in tune mode, then run DSD. At the very least you should see it start logging whenever the voice channel becomes active. It should also decode the audio, but you may have to play around with the input levels a bit to find the sweet spot.

You should definitely start out by making sure it can even decode the signal on a single voice channel before getting into things like having Unitrunker control a second scanner. You're also going to need a fairly modern and powerful computer to consistently decode the voice, an old single core processor is probably not going to do the job reliably, if at all.

My personal experience with DSD is that it can be hit or miss with P25 audio, especially if you don't have a good clean signal. I find it decodes MOTOTRBO much better. Your mileage may vary.
 

alfonzo1955

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My scanner seems to track the digital channels fine. I know which talkgroups are digital and I see them show up but DSD has no output.
 

kma371

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I'm trying to help but I'm not understanding you.

If your scanners tracking it fine, then what are you needing the DSD for?
 

DaveH

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I'm trying to help but I'm not understanding you.

If your scanners tracking it fine, then what are you needing the DSD for?
The scanner can't decode P25, so he's trying to use DSD to do that. The scanner
is tracking the digital TG, and feeds audio to the DSD decoder.

I'd make sure DSD is actually working, if everything else seems to be OK.
Testing with a P25 conventional channel with fairly continuous transmission
would be good, as you can make adjustments. Problem is, I don't know of
any such channels around Ottawa (which are not trunked, and non-encrypted).

The computing platform for DSD matters; the CPU demand is great and many
are not up to it. I think a dual core CPU of at least >1.6Ghz is required (someone
can help with finer details). Audio into the sound card should be adjusted
independently of the sound card controls (an inline volume control cord should
work).

Dave
 

kma371

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The scanner can't decode P25, so he's trying to use DSD to do that. The scanner
is tracking the digital TG, and feeds audio to the DSD decoder.

I'd make sure DSD is actually working, if everything else seems to be OK.
Testing with a P25 conventional channel with fairly continuous transmission
would be good, as you can make adjustments. Problem is, I don't know of
any such channels around Ottawa (which are not trunked, and non-encrypted).

The computing platform for DSD matters; the CPU demand is great and many
are not up to it. I think a dual core CPU of at least >1.6Ghz is required (someone
can help with finer details). Audio into the sound card should be adjusted
independently of the sound card controls (an inline volume control cord should
work).

Dave
Well that's confusing since he says "My scanner seems to track the digital channels fine"

Oh well
 

SCPD

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I *think* the OP means the radio will follow digital calls just fine. The radio's audio with be digital noise instead of voice but the radio does *track* calls as they move from channel to channel. If this is the case but DSD isn't working - I wonder if either (a) the OP is NOT using discriminator audio or (b) the Fleetnet system is simulcast - which is a bit harder to decode.

alfonzo - how is the PSR310 audio connected to your computer? Is this headphone audio or disciminator audio taken from a hard wired tap inside the radio?
 
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