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DMA P25 Decoding and Audio Issues


How can I adjust for the distortion/underwater sounds I hear on the digital trunktrackers?
Some voices are soft, others are loud. How can I fix this?


My audio is cutting out every couple of seconds. What is wrong?

  • You probably have one of the priority features turned on.
    • Close Call Priority -- audio will cut out every 2 seconds on all systems. If your model supports it, check out Close Call Do-Not-Disturb to keep the Close Call feature but lose the "gap."
    • Weather Prioirty -- audio will cut out every 5 seconds on all systems.
    • Conventional Priority -- audio will cut out every 2 seconds only on Conventional systems (that time is user configurable).
  • Another thing that causes audio cutouts is CTCSS or DCS, also known as "PL tone". If audio cuts out on a conventional channel with CTCSS, try changing the modulation setting to "FM" instead of "NFM". If the signal is weak, you may need to lower the squelch setting too.
  • On the BCT15, the bear tracker warning system (bear claw icon) will also cause your audio to cut out every two seconds when active (thanx KB3JNX)


I hear popping or thumping (from the scanner speaker) (from PC speakers). How do I stop this?
I hear a hum coming from the speakers even with nothing received

  • From the scanner speaker - This comes from the audio amp cycling on/off during scanning. It's likely a little DC is leaking into the audio chain at the time the amp is cycling.
  • From PC speakers - (with or without other cables, such as serial or USB cables attached- the solution is the same) - Add one of the following items in the audio line to the PC. The likely cause is a ground loop issue. The first item is easier to obtain; use only 1 pair of jacks. Other distributors exist for similar items. The solution is discussed here


I had a speaker plugged into the speaker out, but when I unplug it I get no audio. What has happened?

  • There is a known issue with the earphone jack. It may require a return to Uniden to fix, unless you are handy with disassembling the scanner to get to the jack to manually reset it.


Im hearing no activity on a trunked system

  • Is the system configured as the correct system type, eg Type II or P25?
  • Are the correct control channels frequencies programmed, are the channels unlocked, and can the scanner "hear" one of the control channels?
  • Is the scanner in ID Scan mode and are any talkgroups programmed? (Alternately, switch to ID Search mode.)
  • Are the appropriate Groups enabled and unlocked with the id's of the talkgroups you want to listen to?
  • Do you have at least one Group Quick Key enabled and allocated for the group where your talkgroups are defined?


Some users are more loud than others. AM sounds softer than others

  • Make sure you are using the correct MODE for your FM systems. For many systems, FM (which assumes 5 kHz deviation) is the correct mode. NFM (narrowband FM, assuming 2.5 kHz deviation) is only for narrowband stations and will make those channels the same loudness as the others. AUTO defaults to NFM and is not the correct setting for most systems on the air today (2010). By 2013 however all systems in the US will have converted to narrowband so NFM will increasingly be the correct setting.
  • You may need to adjust the digital and/or analog AGC settings

Return to the Uniden DMA FAQ


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