P 25 modulation adjustment?

TedTobias

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Hi Happy Tuesday! Is ther anyway to adjust the receive modulation on P 25 systems one transmissions loud one transmission is low I was wondering if I could equalize them out somehow? Hope this makes sense!

Thanks so much!
Ted
 

62Truck

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Which scanner are you using? I believe on some Uniden models there is a digital AGC setting that should equalize the audio.
 

jaspence

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The voice of the user makes a great difference. I have a couple of professional quality DMR radios, and other than ride the volume control, there is not much you can do about the person transmitting. They can be irritating, but the ones who have the mike too close cause distortion and clipping, which makes them hard or even impossible to understand.
 

ofd8001

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It is equally aggravating to radio users. You can send some folks to school and even give them books but they refuse to learn.
 

Ubbe

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Digital radios are much more sensitive to a correct modulation level as the dynamic range are much less than in analog. Also in analog you have clipping circuits that prevent overmodulation and those doesn't exist i most digital systems, it just overmodulate where the digital audio range hits the roof and becomes a square wave with hardly any dynamic range left. If the modulation gets too weak in a digital circuit it will make use of just a few bits at the bottom of the available dynamic and sounds more like a robot.

The audio level needs to be dialed in very precise and microphones have to be used in the exact same way each time, regardless of the enviroments background sound level to sound good in a digital system. An almost impossible task as humans have an inbuilt instinct to raise his voice if there are some enviromental noises. Analog systems are much more tolerant to different microphone use and different types of voices and background noise. Digital systems can use less bandwidth in its communication links compared to analog systems but to the expense of audio quality.

/Ubbe
 

tvengr

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Hi Happy Tuesday! Is ther anyway to adjust the receive modulation on P 25 systems one transmissions loud one transmission is low I was wondering if I could equalize them out somehow? Hope this makes sense!
If particular channels or talkgroups are consistently loud or soft, your can adjust the Volume Offset on each one.
 

bob550

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It is almost like users are not taught how to use 2way radios anymore.
And if they were, I think they all cut class that day. That aside, there's probably more than one cause for the problem the OP describes. Some scanners allow for adjustments to the volume of individual talkgroups. But that's only effective if the volume levels are predictable and consistent. Using this method in conjunction with the aforementioned AGC is your best bet.
 
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