Kenwood TK-3401D Decoding (with DSD+)

OldRabbit

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Jul 15, 2020
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Hi, I am very new to Digital Voice decoding - but have used SDR# & Airspy for quite some time.

I just purchased a Kenwood TK3401D digital PMR - and am attempting to decode digital voice using the guides found for SDR# and DSD+.

Unfortunately, DSD+ does not appear to react to transmission from this unit at all - nothing in the event window.

I do have some partial decoding of data traffic using DSD+, so I know that audio piping is working.

Any idea if the Kenwood is using an unsupported encoding ?

Regards
Mike
 

OldRabbit

Member
Joined
Jul 15, 2020
Messages
62
Hi, I am very new to Digital Voice decoding - but have used SDR# & Airspy for quite some time.

I just purchased a Kenwood TK3401D digital PMR - and am attempting to decode digital voice using the guides found for SDR# and DSD+.

Unfortunately, DSD+ does not appear to react to transmission from this unit at all - nothing in the event window.

I do have some partial decoding of data traffic using DSD+, so I know that audio piping is working.

Any idea if the Kenwood is using an unsupported encoding ?

Regards
Mike
Update - Purchased Fastlane - and according to the event log I am now decoding dPMR - however, I do not hear any voice - only the digital signal in the output.

Will need to find the dummies guide to DSD+
 

jhampton2000

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Joined
Dec 19, 2005
Messages
849
Hi. DSD+ doesn't decode dPMR voice - frames only:

Decoder options:
-P Invert signal polarity (may be required for X2-TDMA and dPMR)
-mp optimize for PSK modulation (will not decode non-PSK)

-fa Auto-detect all protocols / frame types except dPMR [-fa]
-fd Decode D-STAR (no audio)
-fn Decode NXDN4800 (Kenwood NEXEDGE and Icom IDAS)
-fN Decode NXDN9600 (Kenwood NEXEDGE)
-fr Decode DMR/MotoTRBO (TDMA inputs + both output slots)
-f1 Decode P25 Phase 1
-fx Decode X2-TDMA
-fp Decode ProVoice
-fm Enable dPMR decoding (no audio)

You'll need this forked version of DSD (not DSD+) to decode dPMR voice:
 

OldRabbit

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Jul 15, 2020
Messages
62
Thanks - sounds like we may be getting dPMR support - and I don’t quite see the purpose of dPMR (no Audio) - believing that dPMR is audio only - no data ?

Also - would say NXDN9600 not be dPMR ?
 

jhampton2000

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Joined
Dec 19, 2005
Messages
849
Thanks - sounds like we may be getting dPMR support
I doubt it: it's be that way for many years, maybe even as far back as the first release of DSD+ (I'd have to check)

and I don’t quite see the purpose of dPMR (no Audio)
I believe it uses a different format of the standard AMBE+2 codec. So DSD+ does what it can but without the right codec interafce it fails on audio. Again, it's been requested but not added.

Also - would say NXDN9600 not be dPMR ?
Correct - different formats, albeit both FDMA. Confusingly Icom will offer products marketed as IDAS when some use dPMR and some NXDN4800. D-CR is essentilally the same as NXDN4800.
 

OldRabbit

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Jul 15, 2020
Messages
62
I think what confused me was ... that I thought DMR was equal to dPMR. Have seen several DMR decoding tutorials on YouTube using DSD+ - so thought dPMR would be same thing..

Still lot’s to learn
 
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