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Tune audio levels in DStar gateway #analog_bridge

Waldek SP2ONG
 
Edited

Hi,

I would like to set the correct audio levels in my DStar gateway, where I use ircddbgateway / MMDVM_Bridge and 2 Ananlog_Bidges connected via USRP

A simple AB connection diagram is below
 
AB DMR                                                    AB DStar
[USRP]                                                       [USRP]
RX   <--------------------------------------------- TX
TX    ---------------------------------------------> RX
aslAudio = AUDIO_USE_GAIN                    aslAudio = AUDIO_USE_GAIN
dmrAudio = AUDIO_USE_GAIN                  dmrAudio = AUDIO_USE_GAIN
agcGain = 10                                              agcGain = 10
dmrGain = 0.35                                           dmrGain = 0.35

I would like to be sure that when I set the audio levels from DSTAR to DMR I need to correct it:

Tune in USRP_DSTAR agcGain  and dmrGain in USRP_DMR    ????


when I set the audio levels from DMR to DSTAR:

Tune  in USRP_DMR agcGain and dmrGain in USRP_DSTAR     ???

I would like to suggest whether it is correct or how to choose the right levels in both directions

73 Waldek SP2ONG

Steve N4IRS
 

Set one Analog_Bridge to unity in both directions and use the other Analog_Bridge to set levels in and out.

Sent via smoke signal (AT&T)


From: main@DVSwitch.groups.io <main@DVSwitch.groups.io> on behalf of Waldek SP2ONG <sp2ong@...>
Sent: Tuesday, September 10, 2019 7:02:31 AM
To: main@DVSwitch.groups.io <main@DVSwitch.groups.io>
Subject: [DVSwitch] Tune audio levels in DStar gateway #analog_bridge
 

[Edited Message Follows]

Hi,

I would like to set the correct audio levels in my DStar gateway, where I use ircddbgateway / MMDVM_Bridge and 2 Ananlog_Bidges connected via USRP

A simple AB connection diagram is below
 
AB DMR                                                    AB DStar
[USRP]                                                       [USRP]
RX   <--------------------------------------------- TX
TX    ---------------------------------------------> RX
aslAudio = AUDIO_USE_GAIN                    aslAudio = AUDIO_USE_GAIN
dmrAudio = AUDIO_USE_GAIN                  dmrAudio = AUDIO_USE_GAIN
agcGain = 10                                              agcGain = 10
dmrGain = 0.35                                           dmrGain = 0.35

I would like to be sure that when I set the audio levels from DSTAR to DMR I need to correct it:

Tune in USRP_DSTAR agcGain  and dmrGain in USRP_DMR    ????


when I set the audio levels from DMR to DSTAR:

Tune  in USRP_DMR agcGain and dmrGain in USRP_DSTAR     ???

I would like to suggest whether it is correct or how to choose the right levels in both directions

73 Waldek SP2ONG

Waldek SP2ONG
 

Steve,

Thank you, set in the first AB

aslAudio = AUDIO_UNITY                   
dmrAudio = AUDIO_UNITY

and try to tune in the second AB

aslAudio = AUDIO_USE_GAIN                 
dmrAudio = AUDIO_USE_GAIN


and adjust agcGain and dmrGain

One question about a scalar, if I would like to use AUDIO_USE_GAIN, it is only a multiplier, for example agcGain = 2, this is 2 times the level
but if I would like to use AUDIO_USE_AGC, the agcGain scalar will be in dB?

Waldek


Mike Zingman - N4IRR
 

For transcoding, I would never use AGC.  Only use linear gain (AUDIO_USE_GAIN) for best results.

Waldek SP2ONG
 

Mike

Thank you for sharing your experience
and I can confirm your suggestion after the trials I did with linear gain and AGC

Waldek