OK, but when I say variable, the -1758 version reports anywhere from -85dBm to -100dBm on the FDMA control channel. -1352 RSSI was very stable at about -81dBm or so. Note that the target gain graph is a bit choppy compared to -1352 as well (although I think that the flat graph was when the VGA was fixed at 18dBm.
P25RX-II P25RX-II Firmware Updates / Testing
- Thread starter maus92
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If you think there is an issue with the hardware, I would be happy to check it out. Email me if you would like to arrange for that. 15dB off does sound like it could be a hardware issue.
Why would it be a hardware issue if a previous fw version did not do this? Adding that this was one of the earlier builds of RX-II, so if you think it might be a hardware issue, I have no problem with you wanting to look at it. But I am skeptical it is a hardware defect as the issue does not carry over fw versions.
As I mentioned a couple of posts ago, I did make a change to the minimum VGA gain. This is when you started seeing inaccurate RSSI values. I put it back to the value that it was previously in the latest version. If you install the latest (02-03_1032), you may find that the issue goes away because of the shift in the VGA gain. I would expect some variation in the RSSI accuracy for different gain settings, but it shouldn't be off by 15dB.
This is a test with the latest fw, 2-3-1032. Watch that over time, the RSSI begins to deteriorate on the FDMA control channel. The control receiver shows a steady RSSI and symbol plot using the same antenna system. The video is processing over at youtube, the hd version should be complete in a few minutes. There is also some audio from a Smartzone system also recorded, but obviously won't be indicated in the BT control panel. Sorry for that, I forgot to mute that source.
I watched the video. This is definitely not what I was thinking before. You can clearly see that the signal to the receiver drops. The gains shoot up to compensate. There is an issue that lies somewhere between your antenna and the ADC. Can you monitor with a different antenna? This might help you determine where the issue is. I guess you could also try swapping cables with your other system using the shared antenna. It doesn't appear to be a firmware issue.
Weird. The other two receivers are not experiencing any issues connected to the same stridsberg. The only difference between the three is the short pigtail, so I will swap that, but still unexplained is the stable RSSI on the FDMA cc a few versions back as there has been no antenna system / line changes, and I don’t physically touch the device as it is remotely mounted.
Thank you. The only other thing I can think of that has been changed that might explain the issue with firmware would be changes to the the channel filter bandwidth. I'm going to revert the channel filter for the P1 mode. I'll have a new release shortly.
02-03_1614 is available. This is a change to the channel filters for P1 and P2. Currently, they are fixed. Once the scanning profiles are added, you will be able to change these parameters per profiles. Profiles will be assigned by frequency.
@maus92, would you try this version when you have time and see if this takes care of the signal issue on the CC?
@maus92, would you try this version when you have time and see if this takes care of the signal issue on the CC?
I'm running 1659 after changing pigtails. Still seeing the same issue, but I brought up another RF tool that is showing some fluctuation with incoming signal strength on the cch that is correlating with the RSSI degradation seen in BT - could be wx related as it is nasty right now. I'll remeasure when the weather clears tomorrow.
freqseeker
Member
My county (King) has been on a Motorola Type 2 analog trunking system at 800Mhz for 20+ years now. This system has good days and really bad days RSSI wise depending on the weather or???. The users complain about it all the time. Now they are rolling out a new P25P2 system this year that looks to be utilizing encryption. 
When P25P2 systems came alive on 700Mhz I found similar flucuations in signal that @maus92 shows in his video. Uniden SDS200, SDS100, BCD325P2 and then P25RX and P25RXll all do the same. Here in the Seattle area we have lots of hills, trees and buildings (even though I'm not in the city of Seattle) to mess with signals.
I do think some of the firmware versions have had higher RSSI values though. Maybe filter or gain differences, or just translation of the rf strength.
I'm obviously not a rf engineer though, just a guess.
Over the years with the analog 800 system I experimented with different antennas and preamps. With preamps I would get excited when I could get more bars of signal (BC780XLT, BCD996T) only to find out I was overloading the front end and received fewer transmissions.
I try to give a day or two run on firmware to make sure it's not local conditions when possible.
I also notice the CC usually has a weaker signal than the voice channels.
Seeing the work Todd puts into this project gives me a greater appreciation for Uniden, GRE etc for what it takes to get things working nationwide or worldwide. Great work Todd.
Now onto the latest firmware.
When P25P2 systems came alive on 700Mhz I found similar flucuations in signal that @maus92 shows in his video. Uniden SDS200, SDS100, BCD325P2 and then P25RX and P25RXll all do the same. Here in the Seattle area we have lots of hills, trees and buildings (even though I'm not in the city of Seattle) to mess with signals.
I do think some of the firmware versions have had higher RSSI values though. Maybe filter or gain differences, or just translation of the rf strength.
I'm obviously not a rf engineer though, just a guess.
Over the years with the analog 800 system I experimented with different antennas and preamps. With preamps I would get excited when I could get more bars of signal (BC780XLT, BCD996T) only to find out I was overloading the front end and received fewer transmissions.
I try to give a day or two run on firmware to make sure it's not local conditions when possible.
I also notice the CC usually has a weaker signal than the voice channels.
Seeing the work Todd puts into this project gives me a greater appreciation for Uniden, GRE etc for what it takes to get things working nationwide or worldwide. Great work Todd.
Now onto the latest firmware.
@freqseeker, thank you for the comments. I also though it looked like it could be a fade in the video, but @maus92 mentioned that his other receivers on the same antenna did not budge on RSSI. This is why I was wondering about a bad cable, connection, solder joint, etc. You are 100% correct that some firmware versions have shown incorrect values. This happens when I change something that affects gains (like filters for example) and then forget to compensate for that using measurements with a signal generator / analyzer. Good comments about the preamps and RSSI. Not everyone understands that. If you put a preamp on the front-end, you are only going to see an improvement in performance if it has better noise figure / gain characteristics then the following amp (and you will limit the dynamic range of the system). Another related point to make is that any attenuation (loss from a long cable for example) before the first LNA (low noise amp) is sensitivity lost that you will not get back with amplification after the loss. This can be a good use case for a preamp, but you need to put the preamp *before* the attenuation/cable loss in order to have an improvement.My county (King) has been on a Motorola Type 2 analog trunking system at 800Mhz for 20+ years now. This system has good days and really bad days RSSI wise depending on the weather or???. The users complain about it all the time. Now they are rolling out a new P25P2 system this year that looks to be utilizing encryption.
When P25P2 systems came alive on 700Mhz I found similar flucuations in signal that @maus92 shows in his video. Uniden SDS200, SDS100, BCD325P2 and then P25RX and P25RXll all do the same. Here in the Seattle area we have lots of hills, trees and buildings (even though I'm not in the city of Seattle) to mess with signals.
I do think some of the firmware versions have had higher RSSI values though. Maybe filter or gain differences, or just translation of the rf strength.
I'm obviously not a rf engineer though, just a guess.
Over the years with the analog 800 system I experimented with different antennas and preamps. With preamps I would get excited when I could get more bars of signal (BC780XLT, BCD996T) only to find out I was overloading the front end and received fewer transmissions.
I try to give a day or two run on firmware to make sure it's not local conditions when possible.
I also notice the CC usually has a weaker signal than the voice channels.
Seeing the work Todd puts into this project gives me a greater appreciation for Uniden, GRE etc for what it takes to get things working nationwide or worldwide. Great work Todd.
Now onto the latest firmware.
It resulted in an improvement to the firmware, so that's good. Glad to hear it is working today.
freqseeker
Member
I thought the same until I read this.
Radio is fascinating to me. I like to experiment and figure things out as @maus92 has done.
Over the past 2-3 weeks or so everytime I hook my P25RX up to my ToughBook with Win 7 (now also a Win 10 Tablet) the software just displays Status Erasing App Area, Sending New Firmware Image ... and it says Working in the lower left ... but it never completes.
This is getting really frustrating. How do I get it to complete the Firmware update?
Everything had been fine, all was well, used it daily without issue, now this.
Suggestions?
This is getting really frustrating. How do I get it to complete the Firmware update?
Everything had been fine, all was well, used it daily without issue, now this.
Suggestions?
I take it that you already tried the various USB interface speeds?
brndnstffrd
Member
I use a CF30 running windows 7. Use the slow speed.
I also had the same issue a few times with it getting stuck there. The fix for me was putting the unit into bootloader mode and letting it do the update that way. I switched the speed to slow and I haven't had the issue return even through numerous firmware updates since reflashing it in bootloader mode.
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