Missing Voice With DSD+

[rkillins]

I am actively decoding a DMR Motorola Connect Plus trunking system using DSD+.

DSD+ is getting the control channel signal from my discriminator tapped Pr097 via my line in of my PC soundcard.

I can hear the control channel noise through my speakers. Annoying, but I figure par for the course. My questions for which I hope someone with better familiarity than I with DSD+ can help with.

1) Periodically I hear voice. I am guessing this is DSD+ decoding? But it is drowned out by the control channel noise also being played through the speakers. Is there a way I can eliminate the control channel noise to allow monitoring only of the decoded voice?

2) In #1 above Imentioned "periodically" hearing voice. I will often times see the channel activity panel light up with active talkgroup activity. Sometimes I hear voice associated with the illumination, and many times I don't? Why could this be? Maybe I am misunderstanding what this application does and have too high of expectations. DSD+ is making a .wav file and the voice is almost legible.

3) I don't have all the frequencies of the channels that the control channel has found. Perhaps this is the reason I don't hear voice all the time? I wouldn't think so though as I'm not tuning anything with this information.

4) I edited the DSDPlus.frequencies file to reflect the limited information I know from RR. Channel 1 is the CC tuned at 453.71250, but DSD is displaying it as 452.0375, which is actually channel 2. Is this normal?

Con+, 158, 16, 1, 453.7125, 453.7125, 0
Con+, 158, 16, 2, 452.0375, 452.0375, 0
Con+, 158, 16, 3, 452.6625, 452.6625, 0
Con+, 158, 16, 4, 462.9375, 462.9375, 0
Con+, 158, 16, 5, 0.0, 0.0, 0
Con+, 158, 16, 6, 0.0, 0.0, 0
Con+, 158, 16, 7, 0.0, 0.0, 0
Con+, 158, 16, 8, 0.0, 0.0, 0

Thank you all in advance. I am very new to decoding. I have a RTL-SDR dongle on order which I'm looking forward to exploring with. Huge learning curve.

 

[DaveNF2G]

You need to use two receivers.

 

[cg]

Since you cannot control the scanner with the program and tell it to track a conversation, you are limited to monitoring one frequency (2 slots) at a time.
You are hearing the first slot with the control channel noise and when there is a conversation on the second slot, you hear that voice.

DSDPlus uses a different channel number for each slot so you should try changing your frequencies file to:
Con+, 158, 16, 1, 453.7125, 453.7125, 0
Con+, 158, 16, 3, 452.0375, 452.0375, 0
Con+, 158, 16, 5, 452.6625, 452.6625, 0
Con+, 158, 16, 7, 462.9375, 462.9375, 0

chris

 

[rkillins]

I see ... OK guys, thank you! Once I get my RTL-SDR I will be able to monitor voice easier?

 

[cg]

You should be able to use the scanner on the Control Channel and the computer will steer the SDR as the voice channel. You will need to read up on setting up DSDPlus for trunking but it can be done fairly easily.

chris