P25RX P25 Phase 1/2/DMR Receiver With Bluetooth Audio Support

[turnpike61]

You say you have multiple systems that show up as SYS_ID 10, are you sure they are not different sites of the same system? A system can have numerous sites that are part of the same system. Just curious.

It may be. I have no way of telling, since the description tag shows up on some "ID 10" sites, which confirms them, and on others, with widely varying TG's, it does not. All I know is that I really wish I could 1:1 reconcile the headers in the TG editor to the Control channel list more easily.

 

[W4KRR]

Would an amplified speaker work with this? Such as this one:

https://www.amazon.com/Uniden-BC23A-Communications-Amplifying-Receivers/dp/B009TNAGDA

 

[turnpike61]

Would an amplified speaker work with this? Such as this one:

https://www.amazon.com/Uniden-BC23A-Communications-Amplifying-Receivers/dp/B009TNAGDA

It should work very well based on my personal testing.

 

[turnpike61]

BTT" Another feature request: can the software be changed to offer a capability to "lock out" entire systems - not just TG's - from the roaming list? I would like to be able to exclude some systems and focus on a single one, or two, depending on what is going on.

Thanks for considering.

 

[btt]

HI BTT: My measurements current stable FW to 10-10.0651:
First, I confirmed good signal strength on all of these an another receiver. The antenna for that receiver is about 10 feet higher, but it let me know that I could copy the signal at reasonable strengths. Each of these is S9+ on a IC-706MKIIG, so I verified each was audible at good strength from my location. The P25RX was connected to a Diamond Discone at 35 feet, and I am at just short of 600 feet ASL up on a ridge. All of these are VA STARS control channels:

Frequency and signal on stable FW and new FW:
152.2025 -89 dbm/-93 dbm
151.070 -112dbm (no sig)/-117 dbm (note: S9+ on other receiver/antenna as well as SDS200 with whip on back)
151.3925 -77 dbm/-81 dbm
152.5475 -78 dbm/-83 dbm

As you can see, all lost signal, which wasn't good to begin with, with the new FW. I could decode with both, but signal strengths were lower.
Also, as a side note, the software does not ouput audio to PC when in FM mode, so I had to attach as separate amplified speaker to listen to the audio when monitoring the P25 CC directly.

Thanks.

turnpike61,
Thank you for making the VHF measurements. The rssi being reported lower with the new firmware makes sense. The max RF gain allowed to the RF agc was decreased (it was too high in previous versions). The reported rssi for frequencies between 130 and 220 MHz were not calibrated correctly. There is a new version available 2020-10-10_0858 with the correct calibration applied for this frequency range. I've verified that the measured return loss for this frequency range is acceptable. I specifically tested frequency 151.07 on two units with an input of -73 dBm (S9) with an HP sig gen. They measure correctly (within 1 dB) with firmware version 10/10_0858. Please give the latest firmware a try. The performance probably will not change from the 1010_0651 version, but the reported signal strengths for 130-220 MHz range should be accurate now.

BTT" Another feature request: can the software be changed to offer a capability to "lock out" entire systems - not just TG's - from the roaming list? I would like to be able to exclude some systems and focus on a single one, or two, depending on what is going on.

Thanks for considering.

I will make sure this is on the list. I think you are the 2nd person to request this.

-------------------------

I have received some good feedback this morning regarding the updates to the audio agc (since version 10/10_0651 this morning). No more clipping/audio pops.

 

[turnpike61]

turnpike61,
Thank you for making the VHF measurements. The rssi being reported lower with the new firmware makes sense. The max RF gain allowed to the RF agc was decreased (it was too high in previous versions). The reported rssi for frequencies between 130 and 220 MHz were not calibrated correctly. There is a new version available 2020-10-10_0858 with the correct calibration applied for this frequency range. I've verified that the measured return loss for this frequency range is acceptable. I specifically tested frequency 151.07 on two units with an input of -73 dBm (S9) with an HP sig gen. They measure correctly (within 1 dB) with firmware version 10/10_0858. Please give the latest firmware a try. The performance probably will not change from the 1010_0651 version, but the reported signal strengths for 130-220 MHz range should be accurate now.


I will make sure this is on the list. I think you are the 2nd person to request this.

-------------------------

I have received some good feedback this morning regarding the updates to the audio agc (since version 10/10_0651 this morning). No more clipping/audio pops.

HI. Thanks for the rapid response. With this new FW, I am seeing the following changes in signal strength indication:
152.2025 - now -86 dbm = +3dbm
151.070 - now -110 dbm - +2 dbm
151.3925 - now -76dbm = +5 dbm
152.5475 - now -78 = +5 dbm

I have not noted any pops in the audio.

New questions: since the DB you are pulling from (FCC records?) doesn't present me with these CC's, I have to add them manually, and the software lets me do that. Frequencies are entered and save properly in roaming flash. However, any customization I make to any other field on the Control Channel tab is not "sticky", so I cannot manually enter the grantee or any other information. I have looked in the manual, and have not figured out if I am doing something wrong, or if this is a software limitation.

Thanks.

 

[W4KRR]

New questions: since the DB you are pulling from (FCC records?) doesn't present me with these CC's, I have to add them manually, and the software lets me do that. Frequencies are entered and save properly in roaming flash. However, any customization I make to any other field on the Control Channel tab is not "sticky", so I cannot manually enter the grantee or any other information. I have looked in the manual, and have not figured out if I am doing something wrong, or if this is a software limitation.
Thanks.

I noted the same thing. You can manually enter frequencies, but nothing else.
I also noticed that not all trunking systems appear in a database search. Example: Searching a 30 mile radius of Miami Florida doesn't bring up the Miami-Dade County P25 trunked system, which is probably the largest Public Safety trunking system in South Florida, if not in all of Florida.

 

[btt]

I have not noted any pops in the audio.

New questions: since the DB you are pulling from (FCC records?) doesn't present me with these CC's, I have to add them manually, and the software lets me do that. Frequencies are entered and save properly in roaming flash. However, any customization I make to any other field on the Control Channel tab is not "sticky", so I cannot manually enter the grantee or any other information. I have looked in the manual, and have not figured out if I am doing something wrong, or if this is a software limitation.

This is currently a software limitation. This is already on the list of needed features. You can manually add the frequencies (which do get stored in the P25RX flash memory), but the other information is part of a compressed .zip flat-file database. In order to solve this in a future software version, it will probably store the extra user information in a separate file. Eventually, I would also like to integrate RR DB API functionality into the software.

 

[btt]

I also noticed that not all trunking systems appear in a database search. Example: Searching a 30 mile radius of Miami Florida doesn't bring up the Miami-Dade County P25 trunked system, which is probably the largest Public Safety trunking system in South Florida, if not in all of Florida.

Do you know if this system is in the FCC database? Maybe this is another case where this is only in a state-maintained database?

 

[btt]

I want to emphasize that even though the unit is reporting poor decode the voice decode is actually very good. If it didn't report the signal quality I would not have known there was a problem (if there even is one).
This is the WSP 700 system that is multicast on the Federal VHF system I listed above as well as the original conventional P25 channels. I'm not a RF engineer but there could be an issue caused by the multicasting.
I am very impressed with this little unit.

freqseeker,

I just found something that could be causing this issue. Can you test a new version 2020-10-10_1135 on the web site and see if your control channel with the low TSBK/sec count and erratic sync is improved?

[edit]
I should probably give some more explanation. I have been puzzled by the plots shown by freqseeker where the symbol plots show such a great looking SNR and symbol sync, but also show a terrible TSBK/sec for the control channel. Combine this with freqseeker reporting that the voice channels work great despite this. I started thinking this might indicate that something is wrong with TSBK decoding.

I found that the sync timeout defined would not be long enough for full-length, multi-part TSBK messages. I'm wondering if this is the cause of the issue. _1135 version has an increased sync timeout for these message types.

 

[W4KRR]

Do you know if this system is in the FCC database? Maybe this is another case where this is only in a state-maintained database?

This system appears in the FCC database under several different callsigns as "Miami-Dade County".

 

[btt]

This system appears in the FCC database under several different callsigns as "Miami-Dade County".

Thanks. I've been looking into this. It looks to me like the reason these records didn't work is because the latitude information is missing (longitude is there). I haven't looked at this for quite a few months, so I might be missing something.

[edit]
No, I was wrong on that. Looking at the wrong columns.

 

[freqseeker]

I just found something that could be causing this issue. Can you test a new version 2020-10-10_1135 on the web site and see if your control channel with the low TSBK/sec count and erratic sync is improved?

I drove to the site while monitoring the signal and error rate. No change in TSBK as the signal increased. I wanted to rule out my home location and antenna. I didn't think it would change. I did note that the IQ plot went from small four corner groups to an X pattern when mobile.

I have the 1135 firmware running and there is no change that I can detect.
Is there anyone else seeing this behavior? If not I assume it is a system issue.
I will mess with it more later today. I just wanted to rule out local interference issues.

 

[freqseeker]

The above post was for the 700 WSP system. I tried the VHF federal system with 1135 and the TSBK decode has jumped to the upper teens with a blue and occasional green signal. We are having thunder storms at the moment for what that's worth. May have to disconnect outside antenna soon until the storms pass.

 

[boy7777777777]

Mine has always went to an x pattern when mobile since I’ve owned the unit, but it decodes flawless regardless.

 

[btt]

In addition to indicating symbol synchronization, the "X" pattern indicates that the amplitude is changing (some of the symbols are closer to zero than others). This can be due to modulation, being mobile, moving the antenna around, fading, etc.

 

[btt]

This system appears in the FCC database under several different callsigns as "Miami-Dade County".

I think I figured it out. The Miami-Dade FCC entries are listed as non-fixed, mobile classification. I was not putting mobile units into the database. I added them and the database size only increased by around 1MB, so I'll leave them in there. This is the only change to version 10/10_1500 (not a firmware update, software only).

 

[btt]

The above post was for the 700 WSP system. I tried the VHF federal system with 1135 and the TSBK decode has jumped to the upper teens with a blue and occasional green signal. We are having thunder storms at the moment for what that's worth. May have to disconnect outside antenna soon until the storms pass.

I went back and looked at the plots and see that the WSP 700 system is getting around 25 TSBK / sec? I have seen some systems that only transmit 27 TSBK/sec instead of the usual 40/sec. There may be nothing wrong there. If your VHF has jumped to a blue/green signal quality, that is a large improvement isn't it? That is working pretty good compared to yesterday where you were seeing 0-15 TSBK/sec. Can you post another screenshot of the "signal insights" tab? (once the storms pass).

 

[freqseeker]

I went back and looked at the plots and see that the WSP 700 system is getting around 25 TSBK / sec? I have seen some systems that only transmit 27 TSBK/sec instead of the usual 40/sec. There may be nothing wrong there. If your VHF has jumped to a blue/green signal quality, that is a large improvement isn't it? That is working pretty good compared to yesterday where you were seeing 0-15 TSBK/sec. Can you post another screenshot of the "signal insights" tab? (once the storms pass).

The SS911 system (Pierce County) is the one that was getting 25 TBSK.
WSP 700 was the very first plot at 8 TSBK.

Here is a recent plot of the VHF system.



Here is a recent plot of the WSP 700 system. Just now I have watched the TSBK hit low teens with a very occassional blue light. Mostly single digits with very good audio.



The VHF is very much improved.
As I said before if I didn't see the SIG LED and not knowing what TSBK was I would guess the lower number was better (as in number of errors), but I know it's the opposite. I don't think there is a problem, I'm willing to bet as this evolves we will find more reports of this type of decode.
I hope I didn't send you on a wild goose chase.

I noticed the "Estimated Reference Frequency" is red on the VHF plot and green on the WSP 700 plot. What is the threshold and or significance of that?

 

[boy7777777777]

The red means the reference frequency needs adjusted on the P25RX config tab of the software. That will help decode issues. What ever the estimated frequency is, put that in the P25RX config reference frequency box.