SDS100/SDS200: P25/Squelch

[Ubbe]

Invert and Wide Normal shows -116

That's probably your true value, with reference to what you are receiving. The other settings just shows the signal strengh from other systems adjacent frequencies.

/Ubbe

 

[Dexter2]

That's probably your true value, with reference to what you are receiving. The other settings just shows the signal strengh from other systems adjacent frequencies.

/Ubbe

Interesting. Now that I am watching it, I got SQ to 0 and Site Filter Off as mentioned its -45 but I see now when they start talking and only when their talking it its between -108 and -116 and as soon as they are done its right back to -45 faster than light. When the radio is charged I will do the Quick Save.

 

[Ubbe]

only when their talking it its between -108 and -116 and as soon as they are done its right back to -45 faster than light.

That means that the voice frequencies are received ok now but the control data channel are still interfered and the signal strenght detector in the scanner are measuring the level from the strong interfering transmitter.

There's a jump it frequency between control channel and voice channels and it could mean that the filters only can block out one interfering source at a time, as you seem to have several.

Uniden only made it possible to set one common filter for a whole site, from the beginning it was only one global filter for all systems so they have improved on that, which seems a bit unlogical as a site could have a wide spread in frequencies, as you have. I believe there are several users that could benefit from a filter setting for each frequency, so send an email to Uniden with a request for individual frequency filter setting, much like how the IFX functions now are done. Just duplicate that function but instead of On/Off it could have a selection of different settings.

/Ubbe

 

[jonwienke]

I put the Uniden antenna back on this morning. I haven't been able to do the Quick Save yet but so far its the similar song. When I try Filters with SQ on 2 it shows different this time alittle bit: Global and Wide Invert RSSI shows -60, Invert and Wide Normal shows -116 and Normal it disappeared and Off shows -45 and i received traffic as per the usual.

If changing your filter settings changes your RSSI from -45 to -116, then you have some very strong RFI interfering with your reception, and enabling the filter is blocking some of the interference.

 

[jim202]

There is a possibility that there is a bad transmitter on the voice channel causing the low receive level. It should be sending an alarm to the system manager that there is a problem. Just a thought before you pull your hair out. You might try contacting who ever manages the system and ask them if there is a problem they are not aware of.

 

[Dexter2]

It has to receive some data to be able to tell if the encryption flag are raised or perhaps the checksums doesn't match. The log goes on for ages without anything are decoded. At the end of the log it seems to start to work.

Dexter2, can you enter the control channel into Quick Save, channel+859.1125+Enter+Enter and edit at that point to audio mode Analog only. Then push the system button to start scan. Push system button and wait it for it set a hold on a system. Push system again and immediatly use the dial button to scroll thru the systems until you find the Quick save system. Now push the channel button and scroll thru the channels, if there are several, until you find that 859.1125 frequency. Set the squelch to 0 and listen to the audio.

It should be a datasignal there. Compare to the pure noise when you remove the antenna. Use the Uniden antenna to compare if the datasignal are received better. Move around with the scanner and notice if the datasignal are received better or worse.

The log shows that all your frequencies in that system are received very poorly. But the display still show a -50dBm level which is a very strong signal.

It could be the antenna connector that are bad, depends of if other systems at a comparable distance works just as bad. At least that signal strenght indication doesn't work as it should and needs to be repaired at Uniden and people have reported that when they have bad performance the signal strenght could be indicating between -60dBm to -40dBm and all was return to normal reception and signal strenght after a repair.

/Ubbe

So today was the first time I have been able to get the system to work throughout my house. SQ 1 and using Wide Invert, I took it outside and it still worked, however when I got Downtown and it no longer worked, I got it to work using Wide Normal and when I got closer home I switched it back. One thought I did have was, I noticed the Police System frequencies are close in numbers but different towers (not even in the same county) and I live really close to the Police System tower, that may explain and also explain why the closer I got to the Transit system tower it worked fine with SQ on 2 and Global Site Filter.

I just did the Quick Save I believe correctly and nothing happened, it was the same loud noise as if I took the antenna off.

 

[Ubbe]

I just did the Quick Save I believe correctly and nothing happened, it was the same loud noise as if I took the antenna off.

You can listen to that quick save frequency and change the filter to different settings, you can use global setting as it it easier to do, if the Quick save system are set to use global.

If you do not manage to get some datasignal instead of noise then it's not much you can do. The SDS design are using a receive amplifier that set's its gain automaticly depending of the signal it sees, and unfortunatly the receiver are designed mainly for sat and television signals which are 5-10Mhz wide and when used as a 2-way radio receiver in NFM or FM mode it is way too wide in it's signal strenght detector and "false detect" on adjacent frequencies.

The different filter setting are a way to block adjacent frequencies either higher or lower in frequency but cannot do both at the same time. If you are unlucky you have interfering transmitters both higher and lower in frequency and no filter setting will help you. If Uniden had been smart they would have kept the old tried designed like they have in BCD436 and most other scanners and only added a SDR receiver for the final IF frequency to get it to handle simulcast transmissions the proper way. This SDR receiver they are using doesn't have the sensitivity necessary for a scanner so they added a pre-amp which makes things even worse for the SDR receiver to try and cope with a complicated RF enviroment.

/Ubbe

 

[Dexter2]

You can listen to that quick save frequency and change the filter to different settings, you can use global setting as it it easier to do, if the Quick save system are set to use global.

If you do not manage to get some datasignal instead of noise then it's not much you can do. The SDS design are using a receive amplifier that set's its gain automaticly depending of the signal it sees, and unfortunatly the receiver are designed mainly for sat and television signals which are 5-10Mhz wide and when used as a 2-way radio receiver in NFM or FM mode it is way too wide in it's signal strenght detector and "false detect" on adjacent frequencies.

The different filter setting are a way to block adjacent frequencies either higher or lower in frequency but cannot do both at the same time. If you are unlucky you have interfering transmitters both higher and lower in frequency and no filter setting will help you. If Uniden had been smart they would have kept the old tried designed like they have in BCD436 and most other scanners and only added a SDR receiver for the final IF frequency to get it to handle simulcast transmissions the proper way. This SDR receiver they are using doesn't have the sensitivity necessary for a scanner so they added a pre-amp which makes things even worse for the SDR receiver to try and cope with a complicated RF enviroment.

/Ubbe

Thank you for your time through this. I try that tomorrow, but at this point I feel I'm just gonna keep doing what I am doing until this radio kicks the bucket and just listen to the other systems separately.

 

[Ubbe]

There is in fact one thing that you could do if you really want to listen to that system. Don't use that 859.1125 control channel and program the rest of the channels as sites in a new P25 One Frequency System, not in a trunked system, and with NAC ignore. Set the filter for that system so that the voice channels are received as good as you can.

It's much easier for the scanner to decode weak and interfered signals in conventional mode compared to trunked mode.

/Ubbe

 

[Dexter2]

There is in fact one thing that you could do if you really want to listen to that system. Don't use that 859.1125 control channel and program the rest of the channels as sites in a new P25 One Frequency System, not in a trunked system, and with NAC ignore. Set the filter for that system so that the voice channels are received as good as you can.

It's much easier for the scanner to decode weak and interfered signals in conventional mode compared to trunked mode.

/Ubbe

Oh okay thank you for that might try as last resort. For some reason, the RSSI is staying in the 100's now but it still works. I also noticed it mainly works with SQ on 2 where I live in the start of the day, like around 4am-5am I receive more activity with SQ on 2 then as 6am comes and the remainder of the day you see what the videos show. It doesn't last that long as the number of buses out on the road are very few.

 

[Dexter2]

There is in fact one thing that you could do if you really want to listen to that system. Don't use that 859.1125 control channel and program the rest of the channels as sites in a new P25 One Frequency System, not in a trunked system, and with NAC ignore. Set the filter for that system so that the voice channels are received as good as you can.

It's much easier for the scanner to decode weak and interfered signals in conventional mode compared to trunked mode.

/Ubbe

I think I programmed it right, I have four Sites using the four remaining frequencies. I programmed it from the highest to the lowest frequency and I notice its rotating out of order its going Site 0, Site 3, Site 2, Site 1, repeat.

 

[Dexter2]

Good morning - Yesterday I programmed the system additionally as the P25 One Frequency and P25-X2-TDMA just to experiment. Neither worked, no "DATA" and no signal bars. However, on the One Frequency a weird talkgroup popped up on two occasions I don't know what the system was but it was TGID 63335, there was no activity but it did show on the screen for a good 10 seconds. I went back to the correct Trunked system. I could have programmed the two types wrong but that was my experience and I'm not sure what the difference is was the X2-TDMA.

 

[jonwienke]

X2-TDMA is obsolete, and guaranteed not to work.

 

[Dexter2]

Update 5/20/2020 - With the One Frequency, Nothing happened I left it on for two days, so yesterday I added the 859.1125 frequency and it showed DATA and signal bars on the screen, I soon then recieved activity but there was no sound. If I understand correctly once 859.1125 picked up the data from the call it was supposed to switch to the Site with the voice channel, but it did not.

Also, on the original Trunk system I am now able to pick up on the 2nd Site but it appears because its in alphabect order. For instance, if I alter anything (volume, go to radio settings, etc) it appears it starts scanning at the 2nd Site which is Altamont, I recieve perfectly, once the call is completed it proceeds to the Brunswick Site and stays on there thereafter. Not sure if the firmware update helped this, but this never happened before. So now, I have both Sites on and the 3rd one still avoided.

 

[Ubbe]

Update 5/20/2020 - With the One Frequency, Nothing happened I left it on for two days, so yesterday I added the 859.1125 frequency and it showed DATA and signal bars on the screen, I soon then recieved activity but there was no sound. If I understand correctly once 859.1125 picked up the data from the call it was supposed to switch to the Site with the voice channel, but it did not.

It probably switched to the voice channel but it had no reception from that frequency. The filter you are using are the best for the control channel, so you are receiving that, but the filter are not the best for the voice channel. If you choose another filter it will kill the control channel, that is ok, but will receive the voice channels, that is what you want when scanning it as a one frequency system.

Also, on the original Trunk system I am now able to pick up on the 2nd Site but it appears because its in alphabect order. For instance, if I alter anything (volume, go to radio settings, etc) it appears it starts scanning at the 2nd Site which is Altamont, I recieve perfectly, once the call is completed it proceeds to the Brunswick Site and stays on there thereafter. Not sure if the firmware update helped this, but this never happened before. So now, I have both Sites on and the 3rd one still avoided.

It probably shouldn't do that if the two sites belongs to the same system. As soon as a call has ended it will skip all other sites in a system and instead proceed to the next system. That is how I understand it and also how it works in my scanner. But it could also be dependent of the system type and firmware version.

/Ubbe

 

[jonwienke]

If the system is a standard P25, programming it as One Frequency will break the control channel / voice channel functionality. Programmed system type needs to match actual system type, or things aren't going to work right.

 

[Ubbe]

It's still gonna work better than it does now.

/Ubbe

 

[Dexter2]

With the One Frequency: I programmed the four frequencies for the system, as Ubbe mentioned to leave out the 859.1125. When doing so, nothing happened, it would simply rotate between Site 0, Site 3, Site 2, and Site 1. Never picked up any activity or talkgroups. Never showed the word "DATA" or any signal bars. I played with the different Filters and on one occasion I picked up a Talkgroup ID: 633335 (Note: no system ID,WACN, or anything popped up for this), thought that was a strange number and it disappeared after five seconds. I then added the 859.1125 frequency (Site 4). Once I did that, DATA and signal bars appeared (Note: the system ID, etc showed) and it stayed on that for awhile. That's when I began receiving the usual known Talkgroups. I then saved those, but then I noticed it would stay on that 859.1125 frequency and not rotate to the voice channel frequencies in Sites 2 and 1. Also, when I watched the activity now, there was no sound, I could see the activity on the screen but there was no voice.

Now with regarding the usual system, I should have rephrased. When I reprogrammed the radio this time around, I did not Avoid Sites right away, that's when I noticed I am now able to receive some activity on Site 2, though I always use and live near Site 1, and I Avoid Site 3 Completely. But this only happens if I turn the radio on originally, no longer hold on a Talkgroup, or return to scanning after I was in Settings. For example: When I turn the radio on now, it will start out on Altamont Site 2, if there is no activity on Talkgroup 20 (just an example) it will continue and rotate to Site 1 the Brunswick site, and it will remain on that Site until activity. Now, if there was activity on 20 when I turn the radio on under Altamont, it will remain there and I will listen to the transmissions once complete it will do what I said above and move on to the Brunswick Site. When I'm holding on the two sites it rotates as it should I believe. The comment now is because this had not happen before since I added this new bin/firm files. All this time before, I only picked up the Altamont Site if I went to that county the tower is in and thus I would loose the Brunswick Site. Now that I am able to pick up Altamont at times, the chances of me missing Talkgroup 20 are a lot slimmer.

But again, there also may be the radio issue because this system only works perfectly consistently with Squelch on 1.

 

[werinshades]

With the One Frequency: I programmed the four frequencies for the system, as Ubbe mentioned to leave out the 859.1125. When doing so, nothing happened, it would simply rotate between Site 0, Site 3, Site 2, and Site 1. Never picked up any activity or talkgroups. Never showed the word "DATA" or any signal bars. I played with the different Filters and on one occasion I picked up a Talkgroup ID: 633335 (Note: no system ID,WACN, or anything popped up for this), thought that was a strange number and it disappeared after five seconds. I then added the 859.1125 frequency (Site 4). Once I did that, DATA and signal bars appeared (Note: the system ID, etc showed) and it stayed on that for awhile. That's when I began receiving the usual known Talkgroups. I then saved those, but then I noticed it would stay on that 859.1125 frequency and not rotate to the voice channel frequencies in Sites 2 and 1. Also, when I watched the activity now, there was no sound, I could see the activity on the screen but there was no voice.

Now with regarding the usual system, I should have rephrased. When I reprogrammed the radio this time around, I did not Avoid Sites right away, that's when I noticed I am now able to receive some activity on Site 2, though I always use and live near Site 1, and I Avoid Site 3 Completely. But this only happens if I turn the radio on originally, no longer hold on a Talkgroup, or return to scanning after I was in Settings. For example: When I turn the radio on now, it will start out on Altamont Site 2, if there is no activity on Talkgroup 20 (just an example) it will continue and rotate to Site 1 the Brunswick site, and it will remain on that Site until activity. Now, if there was activity on 20 when I turn the radio on under Altamont, it will remain there and I will listen to the transmissions once complete it will do what I said above and move on to the Brunswick Site. When I'm holding on the two sites it rotates as it should I believe. The comment now is because this had not happen before since I added this new bin/firm files. All this time before, I only picked up the Altamont Site if I went to that county the tower is in and thus I would loose the Brunswick Site. Now that I am able to pick up Altamont at times, the chances of me missing Talkgroup 20 are a lot slimmer.

But again, there also may be the radio issue because this system only works perfectly consistently with Squelch on 1.

You've been working on this a long time. After many suggestions, and you've ruled out programming issues, I would suggest sending it in for repair with that squelch issue to start and any other problems noted. You would have had it back by now from Uniden with a 4-5 week turnaround on average. You're not getting sufficient decode to monitor the systems for whatever reason. Maybe do that and after you get it back, post the results?

 

[Dexter2]

Is -100's RSSI and one to three signal bars a normal reading?