is there an Issue with p25 p2?

[I_Am_Infinite]

I've had my sds 200 for about 2 months or little more, no issues but seems to get interference at times, similar to like when u have say 2 people trying to talk at same time on same frequency. I noticed it would get a little digitally reception with 5 bars and I'm like wtf, so I watched and after the transmission there was, another talk group active on the same frequency on slot 2.

Does these scanners have a little issue with reception when there is 2 talk groups active on the same frequency even thou one tg using slot 1 and other slot 2. Its like they interfere or the scanner can't adequately separate the 2 transmissions..

Maybe others have had this issue or maybe might not even notice if the system isn't very active like the lake county Indiana p25 p2. I've noticed it a few times, and it seems to happen only when both slots r used on same frequency at same time like I've said as if the scanner can't separate the 2 slots from each other very well, it is the only times I've noticed any bad reception is when 2 talk groups on same frequency at same time, anyone else notice this.. Maybe it mine, maybe its something uniden needs to make better with separation of transmissions on the different slots when there 2 talk groups on same frequency..

Thanks

 

[Whiskey3JMC]

More info is needed. How is (are) said frequency(ies) programmed? If DMR is in question, did you program the frequency(ies) conventionally with digital audio mode or as a DMR one frequency system? If the latter you can program in the talkgroups and select which timeslots to pass the audio through per talkgroup

 

[trentbob]

As a rule the SDS radios work very well on tdma Phase ll systems. Not sure your issue is due to what you described.

On the radio itself you might try to use the filters and you very well might find a difference.

On the radio itself using real-time results of performance indicators temporarily use global filters to sample the system on wide normal, invert and wide invert. You are already on normal filter by default. If you see an improvement on any of the other filters then write it down, put Global back on normal as it affects every object on the radio and you don't want to compromise performance on objects where normal works best.

Drill down in the menu and put the better-performing filter on the few sites that you use. The filter that you chose will only affect the system you are having a problem with.

Avoid using the auto filters as they slow scanning way down and put the filter indicator on your display to help you keep track. Since you made the changes on the radio itself so as to hear real-time results it's important that you go and hook up to Sentinel and transfer the data from your card to your profile first thing so as to save any changes you made directly on the radio. This may or may not work but hope it does.

 

[I_Am_Infinite]

More info is needed. How is (are) said frequency(ies) programmed? If DMR is in question, did you program the frequency(ies) conventionally with digital audio mode or as a DMR one frequency system? If the latter you can program in the talkgroups and select which timeslots to pass the audio through per talkgroup

Its on a Lake County Public Safety Trunking System, Countywide, Indiana - Scanner Frequencies and its like it gets interference when there 2 talk groups on 1 frequency, like the scanner ain't quite splitting the 2 apart on each slot well and there bleeding through causing interference. Otherwise it comes in perfect, it only seems to happen when the system sends them on the same frequency. It shouldn't cause any issues because there on different slots even though on same frequency, but it seems to and I've only noticed any interferance when it happens, like I said as If the scanner can't quite split the 2 different transmissions from eachother.

As a rule the SDS radios work very well on tdma Phase ll systems. Not sure your issue is due to what you described.

On the radio itself you might try to use the filters and you very well might find a difference.

On the radio itself using real-time results of performance indicators temporarily use global filters to sample the system on wide normal, invert and wide invert. You are already on normal filter by default. If you see an improvement on any of the other filters then write it down, put Global back on normal as it affects every object on the radio and you don't want to compromise performance on objects where normal works best.

Drill down in the menu and put the better-performing filter on the few sites that you use. The filter that you chose will only affect the system you are having a problem with.

Avoid using the auto filters as they slow scanning way down and put the filter indicator on your display to help you keep track. Since you made the changes on the radio itself so as to hear real-time results it's important that you go and hook up to Sentinel and transfer the data from your card to your profile first thing so as to save any changes you made directly on the radio. This may or may not work but hope it does.

I agree it works very well on this system but few times its like there's interference.. I was listening to a transmission from east Chicago pd on frequency 771.41875 slot 2 and it was not coming thru well (5bars) I'm like wtf, but as soon as that transmission ended it went to st john, lowell, dyer talkgroup on that same frequency 771.41875 slot 1 coming in perfect. I noticed it a couple more times also, on frequencies that were also 5 bars perfect but only happier when there was 2 tg active on same frequency different slots, as if the scanner was not separating them well, its only happened a few times when there's 2 on one frequency.

Usually the system don't use 2 at same time but if its busy on the system it needs to use a frequency for 2 talk groups using the 2 slots on that frequency, and that's when I notice it has like pixelation.

I'm not sure about the filters things, I'm not very good with this scanner yet. Thanks

 

[tvengr]

Does these scanners have a little issue with reception when there is 2 talk groups active on the same frequency even thou one tg using slot 1 and other slot 2. Its like they interfere or the scanner can't adequately separate the 2 transmissions..

You have me confused. In a P25 trunked system, the frequencies go into the site or sites. If you are saying two talkgroups on the same frequency, you must be referring to P25 conventional, which can use the same frequency with different NAC codes. If there is a talkgroup ID (TGID), that could be DMR conventional. If that is the case, program it as one frequency trunk to be able to enter TGID and slot numbers. For the SDS200, you would need the DMR paid upgrade.

 

[trentbob]

Its on a Lake County Public Safety Trunking System, Countywide, Indiana - Scanner Frequencies and its like it gets interference when there 2 talk groups on 1 frequency, like the scanner ain't quite splitting the 2 apart on each slot well and there bleeding through causing interference. Otherwise it comes in perfect, it only seems to happen when the system sends them on the same frequency. It shouldn't cause any issues because there on different slots even though on same frequency, but it seems to and I've only noticed any interferance when it happens, like I said as If the scanner can't quite split the 2 different transmissions from eachother.


I agree it works very well on this system but few times its like there's interference.. I was listening to a transmission from east Chicago pd on frequency 771.41875 slot 2 and it was not coming thru well (5bars) I'm like wtf, but as soon as that transmission ended it went to st john, lowell, dyer talkgroup on that same frequency 771.41875 slot 1 coming in perfect. I noticed it a couple more times also, on frequencies that were also 5 bars perfect but only happier when there was 2 tg active on same frequency different slots, as if the scanner was not separating them well, its only happened a few times when there's 2 on one frequency.

Usually the system don't use 2 at same time but if its busy on the system it needs to use a frequency for 2 talk groups using the 2 slots on that frequency, and that's when I notice it has like pixelation.

I'm not sure about the filters things, I'm not very good with this scanner yet. Thanks

To be honest with you, I actually get a little bit digitally once in a while on my counties tdma Phase 2 system on my apx7000 LOL.

 

[tvengr]

Its on a Lake County Public Safety Trunking System, Countywide, Indiana - Scanner Frequencies and its like it gets interference when there 2 talk groups on 1 frequency, like the scanner ain't quite splitting the 2 apart on each slot well and there bleeding through causing interference.

Missed your post right before mine. On the scanner display, does it stay on P25 Slot 1 or Slot 2, or does it alternate between the 2 when receiving transmissions with the crosstalk problem?

 

[Ubbe]

.... get interference at times, similar to like when u have say 2 people trying to talk at same time on same frequency.

Its on a Lake County Public Safety Trunking System, Countywide, Indiana - Scanner Frequencies and its like it gets interference when there 2 talk groups on 1 frequency, like the scanner ain't quite splitting the 2 apart on each slot well and there bleeding through causing interference.

That system are P25 phase II. Try and increase the delay for the TG's. Maybe you have them set to 0. Your first statement about hearing two people at the same time seems strange. You probably only hear them one at a time and after each other, not at the same time?

/Ubbe

 

[I_Am_Infinite]

Missed your post right before mine. On the scanner display, does it stay on P25 Slot 1 or Slot 2, or does it alternate between the 2 when receiving transmissions with the crosstalk problem?

Ya it stays normal on whatever slot the talk group is using but it seems like i would have a weak signal, so its not coming in good is what it sounds like even with 5 bars.

The scanner operates as normal, but like at times the transmission gets, gargled is probably a better word (digitally or pixely I called it earlier), and the only time I've noticed it is when it seems there also another talk group active on that frequency.

In truth the scanner (sds200) should not have an issue with crosstalk, on a tdma system using different slots. I mean that's what the p25p2 systems are made for, like say it has 10 frequencies on the system but its actually equals 20 really because of slot 1 and 2. But it seems on the scanner when there's 2 on the same frequency it causes interference. Its hard to explain this with words.

All I know it comes in good, but sometimes It gets gargled, which I didn't understand because it's 5 bars signal strength (rssi 70-80s). I was watching it one day and I noticed it was gargled, that transmission ended and another talk group came on, I noticed it was the same frequency that was just gargled and this time (millisecond later) was crystal clear the only difference was a different talk group and different slot. It seemed like that when the talk groups where active at same time it cause the gargled issue as if even thou it was on one talk group and a different slot (slot2), the other active one (slot1) somehow inside the scanner was causing the interference or gargled transmission. Like the scanner wasn't very good at computing, having 2 active talk groups on a frequency at the same time.

So it seemed that it was an issue with the scanner not differentiating the signals well inside it and when there was 2 active talk groups on 1 frequency the scanner gets gargled. Otherwise when there's only 1 slot active there's no issue but when the system is busy and needs to use a frequency for 2 talk groups it gets gargled it seems.

Ubbe, I'm not literally hearing both at the same time, its just when there 2 active it causes gargled transmission. My wording I'm sure sucks trying to explain things.

Well that's about the best I can do to try to explain it.

 

[tvengr]

Ya it stays normal on whatever slot the talk group is using but it seems like i would have a weak signal, so its not coming in good is what it sounds like even with 5 bars.
The scanner operates as normal, but like at times the transmission gets, gargled is probably a better word (digitally or pixely I called it earlier), and the only time I've noticed it is when it seems there also another talk group active on that frequency.

It sounds like you are just having a garbled audio problem unless you are hearing 2 distinct conversations at the same time. That sounds like you are having problems decoding the control channel due to interference. Try using the filters on the Countywide Simulcast site. Invert or Wide Invert often solves the problem. You can try all of the filters to find the one that gives the best decode.
.

 

[I_Am_Infinite]

It sounds like you are just having a garbled audio problem unless you are hearing 2 distinct conversations at the same time. That sounds like you are having problems decoding the control channel due to interference. Try using the filters on the Countywide Simulcast site. Invert or Wide Invert often solves the problem. You can try all of the filters to find the one that gives the best decode.
.

Its definitely a garbled audio issue but it seems to only happen when there 2 talkgroups using the same frequency using the different slots, that's y I said it seemed as though the scanner was having issues receiving the talk group at that moment because the frequency that was being used at that point was also being used by another talk group, since its all good otherwise.

How do you do filters from the scanner controls, I seen a global filter setting but I'd rather try in on just 1 of them, because that's the only one using phase 2 with 2 slot on a frequency and the other things I monitor use phase 1.

Nonetheless it seems whenever its on a frequency, say on 771.41875 and one talkgroup (say 33) is on slot 1 and another talkgroup (say 28) is on slot 2 I notice the garbled audio then, but say talkgroup 33 is on 771.41875 on slot 1 or even slot 2 without the other slot in use its fine, its only when both slots are in use the scanner gets gargled audio.

Also 5 bars decoding the control channel and on voice channels should be perfect, I wud understand if my signal is bouncing from 5 to 4 or 3 bars or less then audio gets garbled, that wud make sense but when it perfect and only happens when there's a frequency with both slots active its weird.

I would definitely like to try some of these filter things just to see what happens really, because everything I pick up is good except when that happens. Thanks

 

[tvengr]

I would definitely like to try some of these filter things just to see what happens really, because everything I pick up is good except when that happens. Thanks

In Sentinel, go the Tools tab and make sure that Target Model is set to SDS200. In the favorites list editor, click on the site and the Options tab and select the filter you want. Save and close the favorites list and write to scanner. You can also select the filter in the scanner menu: MENU > Scroll to Manage Favorites > Press E > Scroll to favorites list > Press E > Review/Edit System > Press E > Scroll to system > Press E > Scroll to Edit Site > Press E > Scroll to site > Press E > Scroll to Set Filter > Press E > Select filter > Press E > Press AVOID to exit menus.

 

[I_Am_Infinite]

tvengr,
Thanks so much I been tinkering with the global one for bit know. I appreciate the information very much.

 

[tvengr]

In the scanner, do this: MENU > Scroll 1 click to the left to Settings > Press E > Scroll to Global Auto Filter > Press E > Select filter > Press E > Press AVOID to exit menus. All sites in the scanner with filter set to Global will be affected by the Global setting. This will NOT affect any site with a filter selected other than Global. The filter in each site defaults to the global setting unless a specific filter is selected.

 

[bemyax]

Here's a thought. If the difficulty lies on the transmission side, no amount of jacking around with the scanner will fix it. (Apologies if I'm out of line here.)

 

[werinshades]

Put this on the Indiana forum if you haven't done so already. This sounds like you programmed in the frequencies as conventional when they should be trunk tracking it. If TGID 33 is transmitting, on Slot 1, you should never see TGID 28 come in right after the transmission on Slot 2 unless you have a TGID Priority set up. Can you post a video and capture it?

About the filters, since you're trying to monitor a 700 Mhz. trunking system, as it was said, try Wide Invert and also try Attenuator on the one site ONLY. Follow the instructions posted, and go from there once you confirmed it's set up as a trunking system.

 

[I_Am_Infinite]

Put this on the Indiana forum if you haven't done so already. This sounds like you programmed in the frequencies as conventional when they should be trunk tracking it. If TGID 33 is transmitting, on Slot 1, you should never see TGID 28 come in right after the transmission on Slot 2 unless you have a TGID Priority set up. Can you post a video and capture it?

About the filters, since you're trying to monitor a 700 Mhz. trunking system, as it was said, try Wide Invert and also try Attenuator on the one site ONLY. Follow the instructions posted, and go from there once you confirmed it's set up as a trunking system.

Na, its programmed right it scans fine there just times when there's is both slots active there's interference, gargled audio.

Here's a thought. If the difficulty lies on the transmission side, no amount of jacking around with the scanner will fix it. (Apologies if I'm out of line here.)

Its very possible i won't be able to fix the issue, especially if its something within the scanner. I think it more in the scanner, when listening to a talk group while there also another on the other slot..

Put this on the Indiana forum if you haven't done so already. This sounds like you programmed in the frequencies as conventional when they should be trunk tracking it. If TGID 33 is transmitting, on Slot 1, you should never see TGID 28 come in right after the transmission on Slot 2 unless you have a TGID Priority set up. Can you post a video and capture it?

About the filters, since you're trying to monitor a 700 Mhz. trunking system, as it was said, try Wide Invert and also try Attenuator on the one site ONLY. Follow the instructions posted, and go from there once you confirmed it's set up as a trunking system.

I understand it seems I'm saying I'm like watching 2 talk groups simultaneously, but ur misunderstanding, maybe I'm not wording it right. Say on my screen I see TGID 33 on slot 1 on frequency 771.41875 when that transmission is done they unkey the scanner searches again it then stops on another transmission and talk group that is active say TGID 28.

Hopefully your with me up to this point.. Well what I noticed is the transmission gets gargled if theres TGIDs (people on the system) on the same frequency using the different slots (both slots in use) but when there only a single TGID active using just one of the slots (both slots not active) it comes in perfect, its like the scanner can't split the two apart well with its technology and if there's both slots active on a frequency its get garbled.

Its damn hard to explain and words are so inadequate.

Here's another way to try to look at it. Say if you had a conventional frequency and not a trunked system as I have now and 2 people try to talk at same time its gets interference. Well when your scanning a trunked p25 p2 the scanners technology keeps the transmissions separate using each slot to avoid interfering with eachother, well its like the technology is not working right, and somehow when say I'm paused on aa talk group that should be coming in perfect, its gets garbled but only if the other slot is active and also regardless of frequency its on , if there only one slot active is fine, also regardless of frequency. Its only when a frequency is active with both slots in use.

So say if I'm on TGID 33 stationary, it can any frequency and come in great but as soon as it gets active by some other TGID using the other slot it gets gargled.

I've tried me best to explain this, so hopefully u cam understand what I mean.. I appreciate all the help, feedback and everything.. On a side not I did gain about 8-10 dBm on RSSI but switching from normal filter to Wide Norm or Wide Invert, I've yet to see if it helps with the issue, and I'm trying see which one I like better Wide N or Wide I based on noise and rssi.

Thanks again

 

[Ubbe]

The garbled sound indicates interference from another frequency. It would explain what happens if you receive another frequency in the system at that 771.48175 channel. It will help somewhat if you have a longer delay set for the TG's, like 5 sec.

I have a similar problem with an analog trunked system that uses some 30 channels in a 2MHz spectrum. They are all weak at -100dBm to -80dBm and what other frequency I hear on the wrong channel depends of what filter and IFX I use. But I am only substituting one interfering frequency with another. So I am totally unlucky with the frequencies in that system.

/Ubbe

 

[werinshades]

Na, its programmed right it scans fine there just times when there's is both slots active there's interference, gargled audio.


Its very possible i won't be able to fix the issue, especially if its something within the scanner. I think it more in the scanner, when listening to a talk group while there also another on the other slot..



I understand it seems I'm saying I'm like watching 2 talk groups simultaneously, but ur misunderstanding, maybe I'm not wording it right. Say on my screen I see TGID 33 on slot 1 on frequency 771.41875 when that transmission is done they unkey the scanner searches again it then stops on another transmission and talk group that is active say TGID 28.

Hopefully your with me up to this point.. Well what I noticed is the transmission gets gargled if theres TGIDs (people on the system) on the same frequency using the different slots (both slots in use) but when there only a single TGID active using just one of the slots (both slots not active) it comes in perfect, its like the scanner can't split the two apart well with its technology and if there's both slots active on a frequency its get garbled.

Its damn hard to explain and words are so inadequate.

Here's another way to try to look at it. Say if you had a conventional frequency and not a trunked system as I have now and 2 people try to talk at same time its gets interference. Well when your scanning a trunked p25 p2 the scanners technology keeps the transmissions separate using each slot to avoid interfering with eachother, well its like the technology is not working right, and somehow when say I'm paused on aa talk group that should be coming in perfect, its gets garbled but only if the other slot is active and also regardless of frequency its on , if there only one slot active is fine, also regardless of frequency. Its only when a frequency is active with both slots in use.

So say if I'm on TGID 33 stationary, it can any frequency and come in great but as soon as it gets active by some other TGID using the other slot it gets gargled.

I've tried me best to explain this, so hopefully u cam understand what I mean.. I appreciate all the help, feedback and everything.. On a side not I did gain about 8-10 dBm on RSSI but switching from normal filter to Wide Norm or Wide Invert, I've yet to see if it helps with the issue, and I'm trying see which one I like better Wide N or Wide I based on noise and rssi.

Thanks again

I do understand and yes you explained it better. Hopefully the filters help and also try the Attneuator. I listen to Starcom on my SDS200 which is also a 700 Mhz system, and that helps me out. If it doesn't work, turn it off, nothing to lose I say.

Did you get a response from anyone monitoring the Lake County system in the Indiana forum? Might be the system as someone else mentioned.

 

[I_Am_Infinite]

The garbled sound indicates interference from another frequency. It would explain what happens if you receive another frequency in the system at that 771.48175 channel. It will help somewhat if you have a longer delay set for the TG's, like 5 sec.

I have a similar problem with an analog trunked system that uses some 30 channels in a 2MHz spectrum. They are all weak at -100dBm to -80dBm and what other frequency I hear on the wrong channel depends of what filter and IFX I use. But I am only substituting one interfering frequency with another. So I am totally unlucky with the frequencies in that system.

/Ubbe

Ya definitely like interference from another frequency, except the frequency seems to be the systems own frequencies when both slots are active.

I do understand and yes you explained it better. Hopefully the filters help and also try the Attneuator. I listen to Starcom on my SDS200 which is also a 700 Mhz system, and that helps me out. If it doesn't work, turn it off, nothing to lose I say.

Did you get a response from anyone monitoring the Lake County system in the Indiana forum? Might be the system as someone else mentioned.

Thanks, I tried my ass off to get that out right, rewriting and writing etc, hopefully others can understand better to. Ya I hope so to messing with both Wide Norm and Wide Invert Im sure I will end up using one of these since I'm getting 8-10 dBm rssi better than before on just Normal, I'm hoping it will fix that issue to but if its in the system or even in the scanner technology not separating them good when using both slots.

Couple other things on a side note, how come some P25 P2 systems like Starcom dont have the slots like some others, like Starcom is P25 but not TDMA? Do they all eventually switch from regular phase 2 to TDMA phase 2. Ok and forget the couple part, I've now forgot my other question 😂.

Thanks everyone