PSR500/PSR600: P25 clicking sounds

[Jn2022]

Hello again everyone! Thank you all for such great help. I am rolling now with a lot of the different police frequencies on both conventional and p25 trunking. One thing I’ve noticed on my PSR-600 though is that it goes in spurts where there is back and forth traffic on the P25 system, it will just start clicking back and forth between the control frequency and voice frequency without making a sound. It sounds like someone is just clicking a mic on and off and not saying anything. It will last for sometimes 4 or 5 seconds. Is this a normal thing or are my settings a little off?

 

[ScannerSK]

I've noticed this at times on the FRCC system in Colorado when using a simulcast control channel. For some reason certain voice frequencies are weaker in signal strength than the control channel so the scanner goes back and forth between the control channel and a kind of non-existant voice channel which creates a slight clicking noise. In an ideal setup, every control channel and voice channel would be broadcast with the same parameters which would prevent this from occurring.

If you watch your scanner display closely, you will probably notice this occurs with the same voice channel frequently however not with other voice channels. At least, this is the problem I experience which causes this to occur.

There really is no setting to help other than possibly a different control channel (non-simulcast tends to be best) or moving the scanner around so the problem voice channel(s) are received with greater efficiency.

Shawn

 

[tvengr]

Is it on a particular site, frequency, or talkgroup?

 

[tvengr]

There are 3 settings for P25 trunking in your scanner. You can experiment with them to see if that helps. In ARC500, go to Global Settings and the Expert tab. You will need to uncheck the Lock box in the lower left corner of the page to be able to make changes. The top setting is for the control channel. The bottom 2 settings are for the voice channels. Make a change in the value and then Upload to Scanner to see if it makes a difference. The default values are shown.

P25 Trunking

96CC HD2 TO Length of time to wait for P25 control channel detection timeout.
Default Value: 30 (300 ms). Values: Enter 10-250 (100 - 2500 ms).

96VC SQ TO Length of time to wait for P25 voice channel RF squelch timeout. Go lower to release squelch sooner, go up to extend squelch longer.
Default Value: 50 (500 ms). Values: Enter 10-250 (100 - 2500 ms).

96VC XF TO Length of time to wait for P25 voice channel digital IMBE timeout.
Default Value: 100 (1000 ms). Values: Enter 10-250 (100 - 2500 ms).

 

[ScannerSK]

I believe the problem occurs when the control channel continuously sends the scanner to a specific voice frequency that is too weak to be decoded properly. No setting is capable of fixing this. About the only fix is to move the scanner into a different location where that specific voice frequency is best received/decoded.

Why engineers/technicians would design a radio system where the control frequency is broadcast with different parameters, such as power output, than each specific voice frequency is beyond me. This seems like a receipe for problems however this is our FRCC system is set up here in Colorado for the Weld County Simulcast control channel. Several of the voice frequencies on the system are much weaker in signal strength than the other voice frequencies which causes issues whenever the control channel sends the scanner to those specific voice frequencies with lower power output.

The original poster may have a different issue however it sounds identical to the issue I experience here in Colorado.

 

[gmclam]

I believe the problem occurs when the control channel continuously sends the scanner to a specific voice frequency that is too weak to be decoded properly. No setting is capable of fixing this. About the only fix is to move the scanner into a different location where that specific voice frequency is best received/decoded.

And make sure you have a great antenna capable of receiving good quality signals from all frequencies of a trunked system (not just the CCs).

 

[Jn2022]

Is it on a particular site, frequency, or talkgroup?

Sorry it took so long to respond back! I do appreciate it. As far as I can tell, it doesn’t really matter on which site it’s on. I think it might be because it’s picking up from Kewaunee County which is to our south. So far, from what I’ve heard, Door county (my county) has not used their P25 system yet, just our neighboring county. Even though our towers are set up for it. They are scheduled to switch over in 2024 so I might just have to wait and see what happens.🤷‍♂️