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Can any of you think of any idea why I would be able to see the UID of a transmission but not hear it?  I'm trying to scan my city's (Joplin, MO) P25 system.  Sometimes I'll hear a patrol officer, a lot of times I won't.  I VERY rarely hear the dispatcher, and very rarely have hear a whole conversation with both people.  It's pretty frusterating to know that the scanner is sensing a transmission but not playing it.  I would say I'm missing the majority of the traffic.

Any help would be appreciated.  I basically just downloaded the data off of radioreference into freescan and have tried a lot of trial and error since.  Mostly error though, I'm pretty new to the digital side of scanning. 

Assuming you are talking about this one,
http://www.radioreference.com/apps/db/?sid=5649

The only thing I can think of is you might have to change the P25 decode settings. You might have a high error rate on receive if it is not adjusted properly and that can cause the symptoms you are having.

How far are you from the transmitters? You could be in a "fringe area" and sometimes you're getting a good enough signal to decode, others time, no. From what *I* have seen, digital does not carry like the old conventional used to. I'm in the KC area and can't pick up the new Johnson County (KS) system in Olathe/Overland Park area. If I go out there with the handheld, it starts talking about stateline so the system is set up correctly.

Assaf,

Yes, that is the system I am trying to receive.  How do you adjust P25 decode settings?  Is it the type (i.e. Mot type II/P25 or P25 Standard (digital XT) or is it something different?    I'm not exactly sure what that system type option should be also, because the radioreference file I downloaded has it set at Mot type II/P25 but most of the other P25 system files I've seen are set to P25 Standard.  Is there a way of telling the right system type from the information in that link you posted?  I have tried it both ways btw, but havn't got anything that works better yet.  Also, I'm not sure if it's part of the problem or not, but when I make a new profile and import the city from radioreference, the first time I upload it to the scanner, freescan shows 1 error saying that the apco band plan is missing or blank or whatever.  It doesn't do it on subsequent uploads of that profile.  I've looked and sure enough the band plan is all zero's, but so is every other P25 system I've seen so far, so I'm wondering if that's normal.  Idk.

Tom Vanderpool,

I do live live on the edge of my city, but get a pretty consistent 3 to 4 bars on the indicator.  I've also tried running it in the truck while I drive around the middle of town, but I still was unable to hear the dispatcher's (and some other units') traffic, even though I could pick up mobile units lound and clear.  It was the same story, I could see UID's on the display showing that someone was transmitting, but it just didn't play the audio. 

The strangest part of all of it to me is the fact that it seems to come and go.  And by that I mean that every once in a while, the elusive unit that I can't hear, I'll all of the sudden be able to her.  then it will stop again.  that's what kinda makes me wonder if there's some missing frequencies in my program file or something. Does anyone know if the trunking system would keep communication on the same frequency between two users?  Knowing that would atleast make the missing frequency theory plausible or busted.

One other thing, this system appearently just very recently underwent rebanding, and rebanding is now supposed to be complete.  I would assume that could/would require some sort of modification of the profile right? 

Is there a way of telling if the radioreference data I downloaded it good for the newly rebanded system?  Would the FCC license have what I need in it?

If it's been rebanded, then make sure you have it set up correctly. That may be what the issue is (and the hint to that may be the initial error you receive with FS on upload). Take a look at how to enter the upper and lower and offset (I think it is). I've not had to do this yet, so can't offer a lot of help. Take a look on RR, has been some talk over there (do a search for reband I suppose).

Tom

I see where to enter the upper, lower, step, and offset, but I have no idea where to find what the step and offset should be.  Is it the same for all P25 systems?


Also, I'm thinking about trying to attack this from a different angle.  I'm new to the 396xt, but shouldn't I be able to somehow just define a frequency range and have it scan all the traffic within that range?  Would that work for this type of setup?

You might check Radio Reference for the upper and lower freqs. I believe I have seen in one of the threads that the step is always the same (up to this point, believe Upman was the one mentioning this).

As for scanning a frequency range, sure, you can do that, but it would NOT TRUNK that range. Remember, on trunking each time they key then COULD move to a different frequency.

Tom

For a full P25 system, he doesn't need the base, offsets etc. The scanner should download all of that from the control channel.

How many signal bars are you getting?

For a full P25 system, he doesn't need the base, offsets etc. The scanner should download all of that from the control channel.

How many signal bars are you getting?

Driving around today, I was getting a steady 4-5 maybe 6 bars (I'm not sure how many it has, but it looked pretty full).  Is it normal for the signal bars to all blink on and off steadily at a rate of maybe once a second?

I made e-mail contact with the administrator of mokanscan (a reigonal scanner page) and the guy told be that he had been down to joplin a couple months ago and scanned the system just fine.  We compared frequencies and he gave me a couple more to add, but it still was the same problem.  Could hear the mobile units, but couldn't hear the dispatcher.  I would have asked him for his programming file, but he was scanning on a pro-106, so I thing that would probably not open in freescan, right?.

Does this at all seem like it could be a hardware issue since I've received the dispatcher a couple times (though very rarely, maybe like twice)?  The only reason I ask is because I just bought it and I'm trying to figure out if I may need to send it back.

I really do appreciate your guys' help btw, hopefully I'll be able to figure out something.

Would you, by chance, know of anyone else in your area that has the same scanner (sorry, can't remember if you're on a 396 or 996XT). You could compare notes with them on this.

If the scanner is receiving any of the folks that use the system, I would say that pretty much tells you that the scanner is working. If you're getting that many bars of signal strength it sounds like you've got a good signal. I guess if all else fails, you could try a hardware reset of the scanner BUT SAVE YOUR PROGRAMMING FIRST!

Tom

The only other thing to check to is to make sure it is operating in Control Channel Only mode. The scanner typically doesn't let you turn this off, but if you are using FreeSCAN it can  be overrode even by accident.

Driving around today, I was getting a steady 4-5 maybe 6 bars (I'm not sure how many it has, but it looked pretty full).  Is it normal for the signal bars to all blink on and off steadily at a rate of maybe once a second?

This cutting in and out could be a priotary, see http://forums.radioreference.com/uniden-scanners/128991-uniden-scanners-new-user.html under "If your audio is cutting out every couple of seconds, then", turn all three off.

If you haven't tried it, how about turning the attenuation on for the system,listed under site setup. If this doesn't help turn it back off.

Does it hang up on a talkgroup like someone is transmitting?  Do you ever see ENC on the screen?

Tom,

Yeah I don't know anyone that has a 396.  I don't even know anyone else that has a scanner.  I have been wondering if a hard reset was in order.  I'll have to find a user manual download to figure out how to do it.  At least I feel a little better that nobody seems to think it's a faulty unit.

Assaf,

That may be a very likely culperate.  I'm not where I can look at it right now, but I do remember seeing a checkbox in freescan for control channel only, and I'm about 90 percent sure it was unchecked.  I never messed with it because I wasn't sure what it did.  I'll definately try that first.

Click23,

Yeah I've turned off the priority modes.  It does hang up on a talkgroup when someone trasmits, just can't hear them (sometimes).  I don't see ENC on the screen ever, which I'm assuming means encoded/encrypted traffic.  I know for sure they don't encrypt traffic on their main talk groups except for certain kinds of calls like armed robberies etc... 

You guys are an awsome help.  I'll try these ideas tonight and hopefully will have something positive to report back.

Also, when you monitor other frequencies or systems, does it do the same thing?  If you do not have anything else programed, switch it over to weather and let us know if it cuts in and out.

Well there's no other p25 systems (to my knowledge) within radio range.  I have scanned other conventional systems like the sheriff's departments and they seemed to all work just fine.  I havn't tried the weather yet.  I've made lots of changes in freescan and whatever changes I've made, atleast the signal bar stays consistantly on.  A steady 3-4 bars.  Occasionally 5.   One of the programming attempts, whenever the uid for the dispatcher would come up, I would hear the speaker come on but not hear any talking.  Then I would hear the mobile unit respond.  I did hear a couple full conversations again last night without changing the programming, but it was short lived, and then went back to how it was before, where I could only hear half conversations.

Can you guys take a look at the tables here at this links.

http://wiki.radioreference.com/index.php/Joplin_Public_Safety_%28P25%29

https://tatoolssecure.800ta.org/PublicTaTools/(wpgk3455czmrhxzogwyls245)/CallSignCheckerResponse.aspx

My question about the table in the first link is if anyone knows what the data columns are.  I'm particularly interested in the 2 columns on the right.  They look like frequencies and I'm not sure if I need to add them to the system somehow.  I can't tell if the table contains the steps and offsets or not. 

On the 2nd link, my question is the far right column.  It says moile freq's.  Seems like kinda the same deal as the first table, but has different numbers so I think it must be something different.  I'm trying to determine if it's saying that the fixed base (fb2/fb2c) is broadcasting on the left columns freq's and that the mobile units are broadcasting on the right columns freq's.  I may very well be mis-understanding it though, so I'm just curious if someone knowledgable on the the matter knows how to read and use it.

Also I'm going to try manually adding every frequency I've ever seen associated with this system from all scanner resources, both pre- and post-rebanding, just in case something is missing.  In the trunk frequencies tab of the system in freescan, there's a column called "LCN" and though the frequencies aren't necessarily in numerical order, the LCN's are.  Do I need to add an LCN number to any freq I add, and if so is it necessary that it be anything in particular or in any particular order?

The only frequencies you have to worry about are the control channel frequencies. LCNs and the rest of the information is superfluous. They are listed for detail, but none of that extra information matters for scanning purposes. All you need are the 2 shown.

Try creating a new P25 system, just enter the two frequencies listed, no TGIDs, and have it on ID Search and it should work. If that doesn't work then you might need to manually enter the P25 bandplan.

Well I tried that both through freescan, and also did a hard reset and tried it directly from the keypad, with no luck.  Still the same story, some traffic comes across, some doesn't.


I guess this may sound like a dumb question, but how do I find out the band plan for a particular system?  None of the resources I've seen online show band plans, I mainly just see frequencies and TGID's.

I am not seeing the 866 range freqs for Joplin in the FCC ULS database. They did have a couple of ranges that were in the 8xx range and I put those in FreeSCAN. You might want to try them and see if/how they work.

The table on RR seems to be quite the mess to me. Not a format I've seen elsewhere on RR.

Tom

I would leave the scanner on a system for a while, then check the band plan on it to see if it managed to download it. If not, then I believe youhave to use one of the trunking programs to find out what it is, but I've never done it myself.

I guess this may sound like a dumb question, but how do I find out the band plan for a particular system?  None of the resources I've seen online show band plans, I mainly just see frequencies and TGID's.

I would leave the scanner on a system for a while, then check the band plan on it to see if it managed to download it. If not, then I believe youhave to use one of the trunking programs to find out what it is, but I've never done it myself.

UniTrunker works with the 396/996. At least version 1.0.0.10 does. Not the EASIEST thing to get working, but I finally saw it run and control the radio. Stopped there, so I'm not much further "In" to this stuff than Assaf.

Tom

Well I appreciate everyone's help, but after a lot of research, it seems like there's a real possibility that the 396xt may not be able to scan this system.  Appearently this has been the official word from Uniden to people on certain other new systems.  I'm still trying to find out a lot of the details, but in the mean time, I'm temporarily throwing in the towel on getting this to work.  I just wanted to thank you guys for your time and effort.

Here's a new version of the file with some additional info I found recently on Radio Reference. Might save you some time/effort.

Tom

Thanks Tom.   I just downloaded it and will try it as soon as I can and report back what I find out. 

Also just to confirm, when you guys scan P25 systems, it will say something special on the screen when they are transmitting encrypted, right?  Like ENC or something just to let me know that it's encrypted.  Mine has never shown anything like that on the screen, so I'm just trying to double check everything to make sure my problem isn't them encrypting their traffic (which I know for fact they very rarely used to do).   I can't imagine they would have started doing it now on all routine dispatch traffic, as it degrades the audio quality so badly, but just dotting my i's.   

Yes, when the transmission is encrypted, you will see ENC on the screen. I just looked and I am seeing the control channel freq display (think I'm in mode 3 from memory) while scanning the P25 system here (Indep).

I have seen link (and something else that I can't remember right now) but that seems to be when the radio is having trouble hearing the broadcast.

In the file, the Joplin3 is the info from what the guy posted at RR yesterday, just did EZ Grab and put it in the file for you. Still not sure why I couldn't find THOSE freqs in the FCC database - guess I'm still a newbie at that. <g>

At least you have a starting place and can play with the file a bit to see what might work best for you.

Tom

Well I'm so disappointed, but I've finally got the answer.  They're encrypted.

I had my 396XT in display mode 3, but it doesn't show ENC anywhere on mine in that mode.  After reading your mention of the word link being displayed, I knew I had seen that atleast once somewhere in one of the other modes and decided to check it out and see if that was the problem.  So I went through the other modes, and in Mode 1, there it was.  Dispatch keyed up and there was ENC right beside it.  I can't beleive it because encryption was one of the first things I suspected, but ruled out because I didn't see ENC on the screen.  That's life I guess.  Murphy is alive and well it would seem. 

Anyway, I can't beleive how many people came out of the woodwork to help me try to figure this situation out.  Real nice bunch of guys the scanning community is.  Just wanted to say thanks to you guys for your time and help.  At least a bad answer is better than no answer. 

Thanks again.

Sorry to hear. I didn't suspect they were encrypted because the database shows them as clear, but sometimes only someone with local knowledge can help.

Well I'm so disappointed, but I've finally got the answer.  They're encrypted.

I had my 396XT in display mode 3, but it doesn't show ENC anywhere on mine in that mode.  After reading your mention of the word link being displayed, I knew I had seen that atleast once somewhere in one of the other modes and decided to check it out and see if that was the problem.  So I went through the other modes, and in Mode 1, there it was.  Dispatch keyed up and there was ENC right beside it.  I can't beleive it because encryption was one of the first things I suspected, but ruled out because I didn't see ENC on the screen.  That's life I guess.  Murphy is alive and well it would seem. 

Anyway, I can't beleive how many people came out of the woodwork to help me try to figure this situation out.  Real nice bunch of guys the scanning community is.  Just wanted to say thanks to you guys for your time and help.  At least a bad answer is better than no answer. 

Thanks again.

I would say it's pretty strange that only one side of the conversation is encrypted (you were hearing dispatch and not cars or vice versa - didn't you say one time it sometimes changed?).

It may be that they are working some bugs out of the system and will be in the clear eventually if they are listed that way on RR. Or might be one or more dispatchers playing with the new toy. When the new wears off, it may be more hassle to hit the encrypt key that just to key up. We can always hope!

Glad you finally have a resolution, not what we wanted to hear, but an answer at any rate.

Tom

Thanks.  Yeah I didn't think about that, but yes, I absolutely have heard that particular UID (the dispatcher's) come across a few times.  Weird.  According to a guy on radioreference, they started encrypting a few months ago.  Yeah I kinda wonder if it's just the dispatchers choice or a new policy.  Unless the audio quality for the encryption has gotten a lot better, I really don't see a sound tactical reason for using it for all calls.  I'd say the vast majority of dispatch generated calls are past tense, like stolen property, accidents, etc... or low priority calls which wouldn't warrant nor benefit from encryption anyway.  Who knows.  Maybe the encrypted audio quality has improved enough that it's not really a nuisance anymore.