996XT failure help!

[jsncrso]

My 996XT isn't picking up one of my simulcast systems!

We had a massive countywide power failure here (no surge, just failure), so I removed my 996XT from it's perch on my desk and hooked it up in my truck with the 12v adapter to continue listening. All was fine for awhile until I noticed I wasn't getting anymore transmissions. Since my home setup includes a yagi antenna setup, I had the 20dB attenuator option enabled, so I turned that off on my scanner thinking that could be the problem, and of course it wasn't.

Fast forward until now, the power is back on and it's hooked up back to the way it was and now my main simulcast system is not being picked up. I can briefly see for a split second the talkgroup ID flash up on the screen repeatedly for the duration of the transmission (alternating with "ID SCAN") but nothing is picked up (it just keeps scanning). I have preformed several hard resets (Hold+2+9) and reuploaded several known good backup files on FreeSCAN and even downloaded fresh from RadioReference, but it doesn't work.

I scan two other systems. The conventional system works great, and the multicast system (with 2 towers scanned) seems to be working for the most part so far, it's just the simulcast system that won't output. I've checked the settings multiple times (and the backups included the settings) and all seems ok on that end.

Also, It's definitely not multipath interference, I have a yagi installed and tuned for this system with a short run of LMR400 and I have not had one issue with any interference for the 8+ months I've had this setup. And it wasn't the power failure either since it was working fine in my truck after for awhile until it died (note, it was the first time I've ever had this scanner mobile).

Anyone have any suggestions for me? I'm getting a bit worried this is a hardware issue.

 

[cg]

Problem with the site nearest you?
Missing only one system indicates the scanner isn't broken but either programming or problems beyond your control. Since you all but eliminated the programming error possibilities, I would lean toward a site problem. Put the scanner in your vehicle and drive around and see if you get it. If it is a trunked system, put the channels in the scanner in conventional mode and see if you hear traffic.Also, if a trunked system and you are doing control channel only, try adding all the channels to the system.

chris

 

[gr8rcall]

Check your rebanding tables,

 

[jsncrso]

Tried all of those, to no avail. Even re-aiming the antenna to different sites did nothing

Tried re-uploading the firmware (v1.06) and scanner won't accept it (yes both COM port baud rates are set and l/o+6 pressed, I've updated from v1.04 with no problems before). The firmware update program from Uniden just throws out an error before it can proceed.

Now, the scanner had a hard time receiving any programming over the serial port. FreeSCAN and ARCXT throw out errors, but I finally got it to accept input over 4800bps and re-uploaded my systems.

I hope Uniden customer support is good, because I'm about to contact them. I'll let you know what they say.

 

[UPMan]

The symptom you describe (briefly showing the TGID but flipping back to the control channel) is a nearly definitive symptom of an incorrect band plan. Sounds like you need to set it to the rebanded table, as suggested.

Re-uploading firmware has no good effect. Firmware is either applied or not.

 

[jsncrso]

Thank you for your reply UPMan. I thought I had done this but apparently I haven't. Can anyone explain or point me to a thread describing how to reband a table?

I thought rebanding was setting older scanners to accept old cell-phone frequencies?

 

[UPMan]

See http://info.uniden.com/twiki/pub/publish/EditBandPlan.html#Rebanded_Motorola_Systems

 

[jsncrso]

One last question, how do I know the parameters to set the band plan to? This is the system I am trying to pick up: Simulcast Site Details (Dare County Public Safety System)

The current configuration I have in FreeSCAN, under APCO 25 Band Plan, it lists:
Position 0, 851.00625MHz, 6.25KHz spacing
Position 1, 762.00625MHz, 6.25KHz spacing

As far as I know, this is what it had been working with all along, although I admit none of that looks correct. I understand the basics of rebanding, I just don't know the parameters, and I had assumed only old scanners had to worry with this.

 

[UPMan]

Actually, that system you should not need to enter a band plan. P25 systems are automatically populated. Are you sure it was programmed as P25?

 

[mikewazowski]

UPMan, you might want to read this article: http://www.aeroflex.com/ats/products/prodfiles/appnotes/8524/P25ControlChannelFunctions.pdf

We had a local P25 system go quiet until we manually entered the band plan that used to be broadcast automatically by the control channel.

It was confirmed by several prople that the system was no longer broadcasting band plans. Several weeks later, things returned to normal.

 

[jsncrso]

I've had it as a P25 Standard (digital XT), but I've also tried P25 one frequency truck and (what's currently on Radio Reference Database) Motorola Type II P25. They all do the same unfortunately.

Mike, what did you do to manually enter the band plan? It sounds like this could be the issue, being the scanner partially picks up the TGID's for a split second.

I will say there was an issue with the system after the power outage. I talked to the local fire chief today and he confirmed this, though the only thing he knew was a ticket was issued last week on it. However, it doesn't explain how other scanners (I know of 3) are still picking up the system just fine (and obviously the county radios are working fine too), especially when it's the same thing when I try to pick up other towers.

 

[mikewazowski]

If its a P25 system, let it scan it for a couple of minutes and then check to see if a bandplan has been entered.

Menu/Program System/Edit Site/Edit Band Plan

If not, then you'll need to figure out what it should be and manually enter it in.

Keep in mind that a P25 system not broadcasting it's bandplan is pretty rare.

 

[UPMan]

I've read that aeroflex paper several times. As you mentioned, it is very rare for the system to be running in "no band plan" mode (DOJ is about the only one I've heard of). You can always blank out the values, then scan the system. If any values get populated, then the band plan is in the data.

 

[SCPD]

~~~nevermind~~~~
Edit Site/Edit Band Plan

is different than

Edit System Option/Edit Band Plan

 

[jsncrso]

Alright, I went into the scanner directly and zeroed out both band plans for that system (the first one was 851.00625MHz and the second one was 762.00625MHz, both with 6.25KHz spacing) and hit E to save. After scanning the system for about 5 minutes, I checked again and the scanner repopulated the band plan with those same values.

I also went back and checked my FreeSCAN know working backup files from over the summer, and they have the same values as well.

So it seems the system broadcasting a band plan (albeit one that doesn't make sense to me). Unfortunately, this did not work and my scanner is still not working.

 

[gr8rcall]

What system are you trying to monitor? Can we get a link?

Also, try asking in the NC forum, as it may not be your scanner, but something with the system. It might be, or has been, or has in the past, happened to others!
NC forum here:
North Carolina Radio Discussion Forum - The RadioReference.com Forums

When you post there, give the following info:

What system.
What area.
What scanner.
What YOU'VE tried.

(I'm sure you know all that, but if its a system problem, the NC folks (like me) or going to want all that stuff.)

 

[jsncrso]

Its the Dare County P25 system: Simulcast Site Details (Dare County Public Safety System)
VHF and NC VIPER scan perfectly.

(and I did post in the NC forum under "Dare County issues

I know of 4 other people who are still scanning the system with their scanners without problems (Two using GRE, asking the other two now), so it's definitely an issue with my scanner. And I've tried resets and uploading known working backups multiple times, and resetting the band plans. Scanner is a 996XT with v1.06 firmware.

 

[PVPD730]

Sounds a bit silly, but have you checked the squelch? I had a similar issue recently where I relocated my 996XT for cleaning and somehow the squelch got out of whack. I normally keep mine set at 2, and it was set to 10 after I turned it back on. Might be worth a check...

 

[jsncrso]

Sounds a bit silly, but have you checked the squelch? I had a similar issue recently where I relocated my 996XT for cleaning and somehow the squelch got out of whack. I normally keep mine set at 2, and it was set to 10 after I turned it back on. Might be worth a check...

*cue the biggest facepalm on the entire earth...*


That was it! Somehow the squelch got turned up in my truck. I never even considered that being the other systems worked flawlessly. Plus I thought the knob was software based (nope!). Thank you so much for your suggestion, I can't thank you enough! And everyone else, thank you as well and take note of this for future reference

 

[gr8rcall]

Sounds a bit silly, but have you checked the squelch? I had a similar issue recently where I relocated my 996XT for cleaning and somehow the squelch got out of whack. I normally keep mine set at 2, and it was set to 10 after I turned it back on. Might be worth a check...

I thought about that, but didn't want to insult the OP.

(I'm not saying you did either) GREAT WORK!!!!!!