P25RX Tips And Tricks

Changes To The Roaming Mode Of Operation

Starting with version 2021-01-08_1810, the P25RX has improved roaming capabilities. Control channels are tracked dynamically and persistently across frequency changes. It will scan up to 16 control channel frequencies defined in the roaming flash memory. Add all frequencies to be scanned (including the "primary") to the roaming flash. This version uses up-to the first 16 entries defined in the roaming records. If you set the "Switch Control Channel After xx Secs Of Inactivity" to 0, then it will use the control-channel IDLE/BUSY bits to determine if it is time to move to the next channel (this results is much faster scanning). If there is voice activity, then it will remain on the current control channel for the defined talk group timeout (default of 2 seconds).

Scanning NXDN Voice Channels

Starting with version 2021-01-08_1810, the P25RX can be used to scan NXDN-4800 voice channels. Follow these steps to start scanning:



Reference Frequency

The reference frequency is the frequency of the internal reference. This determines frequency accuracy of the frequency synth and the A/D converters. You can use the ref freq value printed on the labels that the device came with or if you are currently monitoring a P25 Control Channel and the device has had some time to warm up, you can use the "Estimated Reference Frequency" shown on the "Signal Insights" page.

Talk-group Auto-Flash

By default, the configuration software has two options "auto flash" and "auto disable encrypted" in the talk-group editor tab enabled.  As new talk groups start coming in, the "auto flash" will write each new talk group to the P25RX flash memory.  As it is writing to flash, there is a brief interruption to the voice audio output.  If you have a system with many talk groups,  you might find it preferable to disable the "auto flash" in the beginning and just manually write the entire list of newly discovered talk groups when you are ready using the "Write Talk Groups" button.  This will prevent the audio from being interrupted every time a new talk group is added to the list.  Once you have a near complete list, you can re-enable the option so that any new talk groups that come in get captured to flash automatically.

$ ls altcc     (list the 'learned' alternate channels)

P25 Alt Control Channels
SYS bee00-34a, PRIMARY 859.962500, ADJACENT 858.987500, Site 2, RFSS 1
SYS bee00-34a, PRIMARY 859.962500, ALTERNATE 859.937500, Site 1, RFSS 1
SYS bee00-34a, PRIMARY 859.962500, ALTERNATE 858.962500, Site 1, RFSS 1
SYS bee00-34a, PRIMARY 859.962500, PRIMARY 859.962500, Site 1, RFSS 1
SYS bee00-34a, PRIMARY 859.962500, ALTERNATE 858.937500, Site 1, RFSS 1

$ <space>  (hitting space stops scrolling display, hit return to resume)

Reset Configuration To Default Values

If you decided to experiment changing various things with console commands and used the 'save' to write non-default values to the flash memory,  you can always reset to factory values with the

$ factory

command in the console.  This will reset configuration to default values and reset the device.

Troubleshooting - BTConfig will not start in Windows

This isn't happening for most people.  If this happens on your system, this is very likely due to Windows Defender blocking the application.  It is reported that Windows Defender may not even warn you that this is happening.  You may have to start the software manually on the command line in order to see the reponse from Windows Defender.  At this point, you will be able to verify that the application is ok for Windows to open.