Whistler TRX1 Volume on different Trunked Radio Systems

[MrGroovy]

I have 3 Moto Phase 1 TRS systems and one Harris Phase 2 TRS. How do I adjust the volume so that the Harris Phase 2 TRS is the same volume as the MOTO TRS systems?

 

[Wackyracer]

There is no way other then buying a 2nd scanner and putting each system on its own scanner and adjust the volume appropriately to balance them out.

 

[JD21960]

Make sure AGC is checked on for your SYSTEM AND individual SITES. Also loudness for digital can be played with* using DAC and ADC GAIN* in the controls of the scanner under global settings

 

[tvengr]

Try this: (354) TRX-1: - Volume equalization between P25 Phase 2, Phase 1, and other modes | RadioReference.com Forums

 

[Wackyracer]

Try this: (354) TRX-1: - Volume equalization between P25 Phase 2, Phase 1, and other modes | RadioReference.com Forums

DAC adjustment is great until your decoding suffers....But if it works for you and no decoding issues then certainly use it!

 

[Ubbe]

DAC adjustment is great until your decoding suffers

isn't the DAC converting the digital signal from the DSP to analog to the audio system, the level that can be adjusted to match the native analog audio levels.

And ADC converts the receivers demodulated analog signal into digital that then feeds the DSP, and it is ADC that sets the decoder quality of digital signals together with the DSP level?

/Ubbe

 

[Wackyracer]

isn't the DAC converting the digital signal from the DSP to analog to the audio system, the level that can be adjusted to match the native analog audio levels.

And ADC converts the receivers demodulated analog signal into digital that then feeds the DSP, and it is ADC that sets the decoder quality of digital signals together with the DSP level?

/Ubbe

If the DAC is too low it is possible the DAC converter will not properly convert it to analog.

What is a DAC (Digital-to-Analog Converter) and How Does it Work?

Ever wonder what’s going on inside your audio equipment? How does the audio data on a CD, MP3, or WAV file stop being data and become sound? That “magic” is in large part thanks to a digital-to-analog converter, or DAC.

www.audioadvice.com

and here is how it applies to the Whistler scanners

GRE/RS/Whistler based DSP ADC/DAC Adjustments - The RadioReference Wiki

wiki.radioreference.com

 

[Ubbe]

If the DAC is too low it is possible the DAC converter will not properly convert it to analog.

No, it's just the output level you adjust, not the input that comes from the DSP, which is at fixed levels, digital to digital.

/Ubbe

 

[Wackyracer]

No, it's just the output level you adjust, not the input that comes from the DSP, which is at fixed levels, digital to digital.

/Ubbe

The DAC is a decoder (DIGITAL AUDIO DECODER), if you're to low or to high it WILL affect digital broadcast YMMV. Using it for just volume may affect the sound quality of the digital transmission and not just the volume.

 

[Ubbe]

Using it for just volume may affect the sound quality of the digital transmission and not just the volume.

No, its' already done handling the digital decode, you only adjust the analog audio level coming out of the DAC. It has nothing to do with digital quality, only analog audio level. It is the ADC that handles the level of the digital signal , that then goes to the DSP to be decoded and needs a proper level from the ADC to decode successfully.

/Ubbe

 

[dem1]

I read the RadioReference Wiki article on Whistler DSP ADC/DAC adjustments in 2016 when I bought my TRX-1 and could not make much sense of it. Not knowing its veracity, I fell back to Whistler's words in my TRX-1 manual that "DAC Gain sets output signal from CODEC, varying the audio level of decoded digital signals."

If ADC gain adjusts the level of analog input being fed to the analog-to-digital converter for proper encoding, then it makes sense that DAC gain adjusts the level of analog output from the digital-to-analog converter being fed to subsequent audio stages, and ultimately the speaker. That has been its sole perceived impact with my TRX-1.

If anyone with specific knowledge of Whistler's circuits can show that DAC gain actually operates in the digital sphere and could potentially hamper digital-to-analog conversion if set improperly, I'd be eager to learn more.

The "What is a DAC" article cited above discusses using outboard DAC devices for better high fidelity music quality. It is the difference between using a specialized, high quality device designed to perform a critical function, and performing that same function with a general purpose device like a computer or smartphone. But these devices encompass more than solely converting digital-to-analog, and may not be the most relevant example in determining how Whistler's DAC gain setting works.

 

[CycleSycho]

The DAC is a decoder (DIGITAL AUDIO DECODER), if you're to low or to high it WILL affect digital broadcast YMMV. Using it for just volume may affect the sound quality of the digital transmission and not just the volume.

What is a DAC (Digital-to-Analog Converter) and How Does it Work?... If I am not mistaken you may see it is a 'digital to analog' converter.


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[hill]

I don't have this scanner, but do have similar older radio in the PRO-668, The P25 P2 audio has always been way louder than the other P1 systems. I just learned to live with it and it's not too bad, since the audio on the P2 systems are much easier to hear at times.