• Effective immediately we will be deleting, without notice, any negative threads or posts that deal with the use of encryption and streaming of scanner audio.

    We've noticed a huge increase in rants and negative posts that revolve around agencies going to encryption due to the broadcasting of scanner audio on the internet. It's now worn out and continues to be the same recycled rants. These rants hijack the threads and derail the conversation. They no longer have a place anywhere on this forum other than in the designated threads in the Rants forum in the Tavern.

    If you violate these guidelines your post will be deleted without notice and an infraction will be issued. We are not against discussion of this issue. You just need to do it in the right place. For example:
    https://forums.radioreference.com/rants/224104-official-thread-live-audio-feeds-scanners-wait-encryption.html

PSR-800 and Narrowbanding

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Redgranite, WI
#1
Is there anything I can do to improve the audio of a narrowband signal. Our Sheriff's Department went to narrowband. The signal is good but it sounds all digitized and is often difficult to understand. Thank you.
 

DaveIN

Founders Curmudgen
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#2
Did you try turning the attenuators on and off to see if it made any improvement in signal quality? You could try turn off the digital arc.

Narrow band signals are subject to interference of nearby strong signals that may be near the bandwidth of the target signal frequency.
 

Ensnared

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Waco, Texas
#3
PSR 800 & County

Is there anything I can do to improve the audio of a narrowband signal. Our Sheriff's Department went to narrowband. The signal is good but it sounds all digitized and is often difficult to understand. Thank you.
Are you talking about 151.1225? I see where they are also using digital on 155.13 with a NAC of 700. If it is sounding "digitalized", it may very well be digital.

Which one of these frequencies are you talking about when you hear this sound?
 
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loumaag

Silent Key - Aug 2014
Joined
Oct 20, 2002
Messages
12,911
Location
Katy, TX
#5
I just imported that one frequency into my setup to see how it comes in (using EZ Scan) and it comes in as:
  • Mode = FM
  • Squelch = NAC 700
  • DMode = Digital
I'm not sure but why don't you give that setup a try. If that doesn't help, I would then try FMN before going back to Auto on the Mode selection.
 
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May 2, 2010
Messages
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#6
Waushara County Sheriff went to a full-time P25 VHF conventional simulcast system (Motorola Linear Simulcast Modulation). They previously were using mixed-mode analog & P25 and were NOT simulcasting.

All P25 consumer-grade scanners have difficulty dealing with the signal distortion caused by P25 simulcasting, and Waushara's is worse than most. To monitor Waushara County, I have to use a handheld, holding it horizontally and rotating the radio & antenna until I can null-out all but the Poysippi tower. It is a major pain. I don't think Waushara's radio techs have spent a lot of time adjusting the phasing between transmitter sites, which makes it exponentially worse for us.

Plus Waushara County uses digital encryption most of the time, in addition to the simulcasting.

FWIW, Waupaca County also went to a Tait simulcast P25 conventional system on VHF, but their techs have spent a LOT more time dinking with the phasing delay between the transmit sites. Still not perfect, but a lot better than when it first went on the air.

Most actual P25 transceivers have a setting for LSM - simulcast P25, which allows the radio's DSP to discard the distortion-damaged packets, allowing for a clear receive.

Uniden recently released a firmware update for their scanners that seemed to have helped with receiving Waushara County's P25 simulcasting. Unfortunately, no fix from GRE.
 
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