P25RX Tips And Tricks

High Pass Audio Filter (starting with version 2021-09-30_1053)

hpf_cut 0.0  (default)

hpf_gain 1.0 (default)

If you would like to boost the high frequencies (cut the low), then try:

hpf_cut 0.5

hpf_gain 2.0

save

Control Channel Search  (Currently P25RX-II only)

cc_search start_freq channel_sp_mhz bw_mhz dwell_pre-detect_ms [iterations dwell_post-detect_ms]

dwell_pre-detect can be as low as 10.  A value of 25 may detect weaker signals more reliably.

optional parms:

iterations can be 0  (no repeats of search)

dwell_post_detect  (time to wait after signal is detected to see if a protocol is found. default 500ms if not specified. Iterations must be specified if dwell_post detect is to be specified)

In P25 mode,  P25 P1, DMR DATA, DMR VOICE, NXDN-9600 are detected

In TDMA CC mode, P2 Control channels, and P2 Voice channels are detected.

example run:
----------
$ cc_search 450 .00625 20 25 0 1000
signal found 450.000000 MHz
signal found 450.006250 MHz
signal found 451.025000 MHz FOUND P25 P1
signal found 451.075000 MHz FOUND P25 P1
signal found 452.325000 MHz FOUND DMR_BS_DATA_SYNC
signal found 452.325000 MHz FOUND DMR_BS_DATA_SYNC
signal found 453.512500 MHz FOUND DMR_BS_VOICE_SYNC
signal found 453.800000 MHz
signal found 454.306250 MHz
signal found 454.318750 MHz FOUND DMR_BS_DATA_SYNC
signal found 454.343750 MHz FOUND DMR_BS_DATA_SYNC
signal found 454.487500 MHz
signal found 454.493750 MHz
signal found 454.568750 MHz FOUND DMR_BS_DATA_SYNC
signal found 454.568750 MHz FOUND DMR_BS_DATA_SYNC
signal found 454.581250 MHz FOUND DMR_BS_DATA_SYNC
signal found 460.006250 MHz
signal found 460.012500 MHz FOUND P25 P1
signal found 460.637500 MHz
signal found 460.918750 MHz
signal found 460.925000 MHz
signal found 461.025000 MHz
signal found 461.443750 MHz
signal found 461.562500 MHz
signal found 461.700000 MHz
signal found 461.706250 MHz
signal found 461.825000 MHz
signal found 461.850000 MHz
signal found 461.962500 MHz
signal found 462.050000 MHz FOUND DMR_BS_DATA_SYNC
signal found 462.481250 MHz
signal found 462.662500 MHz
signal found 462.787500 MHz
signal found 463.212500 MHz
signal found 463.287500 MHz
signal found 463.375000 MHz FOUND DMR_BS_DATA_SYNC
signal found 463.537500 MHz
signal found 464.825000 MHz FOUND DMR_BS_DATA_SYNC
signal found 465.431250 MHz
signal found 466.668750 MHz
completed cc_search of 3199 channels, in 20.00 MHz of BW, in 551 seconds.
-----------
Logs are found in /Documents/p25rx/mac_id_xxx/p25rx_cc_search-xxx.txt
The number of iterations is optional

Pro96Com / Unitrunker Support

Starting with version 2021-09-15_0005, the P25RX  has full support for Pro96Com control channel data collection via TSBK and PDU type control channel messages. To use it, go to the console in BTConfig and enter the command: 'pro96_en 1'. If you want the device to come up in this mode after a power-up, then also issue a 'save' command. Note the com/serial port shown in the upper left hand corner and exit the BTConfig software. In the Data Configuration option of Pro96Com, select the serial port you noted and select the PSR-800/WS-1080/XXXX option for the scanner model. If you don't want voice channels to stop the data collection and cause missing information, then configure the P25RX to not "allow unknown talkgroups" and then disable all talk groups in the editor. This will prevent the P25RX from switching to a voice channel.

Importing DSD Talk Group Files Available To radioreference.com Subscribers  (starting with version 2021-02-18_0805)

From the front-page on radioreference.com, go to Databases->Frequency Database, and select your state->county. At the bottom of the county page, there is a list of systems. Click on your system. On the system page, select the "Downloads And Reports" tab. Select: "Download DSD Formatted Talkgroup Data File for Trunked System: xxxxx County"

1) Download the DSD Talk Group file from RR and save it to the "Documents/p25rx" folder on WIndows or ~/p25rx/ on Linux.
2) Rename the file to have a '.dsd' file extension.
3) From the Talk Group Editor tab in BTConfig press the "Import CSV" button and select the .dsd file that you downloaded and renamed.

Your P25RX flash memory now contains a list of talk groups for your system!

The files are actually text, csv formatted files. You could append multiple files before the import if you have multiple systems. If you edit these files directly, you must leave the first line of the file intact with the "DSDPlus.groups" string.

No Driver Found For P25RX On Windows 7 Systems

Some users have reported that they get a "no driver found" for the P25RX on Windows 7 systems. If this happens, please use this file to install a driver when prompted:

BTT Driver

The BTT Driver was generously made available by 'Clay Jones, KI4ANZ'. Thank you Clay!

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

If the "Estimated Reference Frequency" is shown in red on the "Signal Insights" tab:

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.