APCO 25 Voice Problems

[Sipho]

I've had this BCD396T about 3 weeks and have been having problems when receiving any P25 systems. short transmissions are not clear. After a few seconds on a longer transmission the audio is sometimes much better. Some voices have higher voice peaks and they distort pretty bad. I've tried setting the threshold to optimize the decode threshold and it helps but still bad. I noticed on the signal strength indicator that it is not steady. Even if I go to hold. It seems to be like scanning. I can get 5 bars but then they drop to 1 or 2. On conventional sysems it is steady. I've tried with AGC both on and off and no change. Close call is switched off. Seems like women voices are harder to copy. I also tried Auto, manual and default on the threshold and also Auto, FM, and NFM with the modulation. They have little or no effect.
Question.. Is this all the better it is suppose to work or do I have a problem with a bad scanner?
Question.. Should signal strength be steady when receiving in P25 mode?

I called Uniden support and they offer little or no help? If I need to send it in then I will but do not want to be without it for 3 weeks and have it come back saying nothing was wrong and it being in the same condition.
I guess what I'm asking is does the P25 system sound as good as the other systems?
At times I can not understand them.

 

[wyldman]

Change the antenna.

Reception is key for for P25.I was having the same problems with our province wide system,until I used a better antenna.Once you get better reception,then you can customize the thresholds and other settings for optimum decoding.

 

[rbm]

Make sure you have the latest firmware installed (1.11.03). That made a big improvement on one of the systems in my area.

Also, I had to set the "AUTO decode threshold start level" on one system to 10 to improve decoding. That improved the initial part of the transmissions. See page 102 (step 5) in the PDF version of the BCD396T Owner's Manual.

If you're seeing the signal drop periodically, it seems that you may have priority or some other function interrupting your reception.

On a 'good' system with a strong signal, it will sound like the person talking is in the same room with you. There is one system that is so bad that I rarely listen to it.

 

[Sipho]

I'm using Radio Shack's Outdoor Scanner/Ham Discone Antenna. 25mhz-1.3ghz.

Thanks for the sugguestions. I will try them.

 

[rfaricy]

An antenna would not cause this on a consistent basis if the radio is stationary.

If it is losing the first part of transmissions only, it is definitely a combination of a decode threshold that is not decoding properly, and the fact it is set to AUTO. You want the decode to be set to the LOWEST setting, and then the lowest setting with the lowest error rate. You should really turn off AUTO and set it to MAN, as that way, transmissions will be consistent, and if they stay garbled, you know you have to change the decode threshold.

Start from 5 and work your way to 10 in MAN mode. You will likely find a setting that will cure this issue.

 

[800crazy1]

mine is set to 10 and auto for decoding CT.STATE POLICE and that really works well for me . excellent reception. as noted by RBM

 

[wjf]

Turn OFF the AGC. Possible that the system is already using AGC and you're bumping into it.

 

[Sipho]

I took your suggestions and went to manual mode and also turned off the AGC and adjusted the threshold and it seems to be doing much better. I do have the latest flash firmware. This did make a huge improvement. I will continue to fine tune to get it better.
Thanks guys for all of your help. You saved me from sending it in and being without it for a while.

Bill - Gilbert, AZ

 

[k46tank]

Where can I find the firmware upgrade for the 996T? I have an older version than what RBM gave in his post. I think mine is 1.02.?? It is out in the car and I can't remember for sure. I went to the Uniden website and I didn't see it anywhere.

 

[DaveIN]

Where can I find the firmware upgrade for the 996T? I have an older version than what RBM gave in his post. I think mine is 1.02.?? It is out in the car and I can't remember for sure. I went to the Uniden website and I didn't see it anywhere.

There has not been firmware upgrade to the 996 to date. I don't think there will be until re-banding has been settled on, but time will tell.

 

[DaveIN]

mine is set to 10 and auto for decoding CT.STATE POLICE and that really works well for me . excellent reception. as noted by RBM

Wow 10, ihink that is some kind of record. I've not seen it that high so far, but if it works that's great.

 

[Sipho]

unwilling BCD396Tscanner on P25 Systems.

I recently bought the Radio Shack 800MHZ antenna and put it to use and my signal did increase by a huge amount. Where my signal strength was unsteady, it now is rock solid and I have 5 bars. I continued to try different settings on the threshold adjustments and using manual mode and any other thing I could think of and it still is terrible reception. So today as of 08/02/06 I sent it back to Uniden for repair. It must be a bad unit from what I hear of other radio coming in clear. Most of the time it is uncopyable and not worth listening to. So I'm very disappointed and I hope that Uniden finds the problem and corrects it as I do want to monitor these P25 systems. So far I can't get any with any decent quality and even when I travel to different locations. So that's the latest on what is happening with my BCD396T scanner that I've had less than 3 weeks.

 

[hiegtx]

I recently bought the Radio Shack 800MHZ antenna and put it to use and my signal did increase by a huge amount. Where my signal strength was unsteady, it now is rock solid and I have 5 bars. I continued to try different settings on the threshold adjustments and using manual mode and any other thing I could think of and it still is terrible reception. So today as of 08/02/06 I sent it back to Uniden for repair. It must be a bad unit from what I hear of other radio coming in clear. Most of the time it is uncopyable and not worth listening to. So I'm very disappointed and I hope that Uniden finds the problem and corrects it as I do want to monitor these P25 systems. So far I can't get any with any decent quality and even when I travel to different locations. So that's the latest on what is happening with my BCD396T scanner that I've had less than 3 weeks.

Sipho,
Which P25 system were you have problems with, specifically? If you are in Gilbert, I'm guessing Maricopa County. Looking at the database, there appears to be only two true P25 systems, Glendale and Phoenix Regional (PRWN). Any others with P25 usage are mixed mode, like Maricopa County, which are programmed as Motorola Type II. If all of them, regardless of type or programming, were giving problems, disregard this suggestion.

 

[Sipho]

Phoenix Regional which includes Phoenix, Gilbert, Tempe, Chandler & Mesa are the ones that are causing me problems. I pick up Simulcast D for Mesa, and C for Tempe/Chandler.
I have not been able to piick up the Phoenix Police however on Simulcast A. The Maricopa Trunk works very well. I guess it is mainly the Phoenix Regional that is not working well.
I never tried Glendale as it is a good distance from me. I'm on the East side and they are on the West side.

 

[hiegtx]

Phoenix Regional which includes Phoenix, Gilbert, Tempe, Chandler & Mesa are the ones that are causing me problems. I pick up Simulcast D for Mesa, and C for Tempe/Chandler.
I have not been able to piick up the Phoenix Police however on Simulcast A. The Maricopa Trunk works very well. I guess it is mainly the Phoenix Regional that is not working well.
I never tried Glendale as it is a good distance from me. I'm on the East side and they are on the West side.

Sounds like you've covered most of the obvious trouble spots. It could be either a bad scanner (you say you've sent it in?), or some really weird P25 adjustment setting required on this one system (there are differences).
Make sure each site is a separate system. Don't combine sites. If you do, the scanner will find the first active control channel in the "system" file, then move on to the next system. It will not check the other control channels loaded in the same system.
Don't be surprised if Phoenix does not appear on the sites in your area. Often, in this type system, the radios (handheld or vehicle) are associated with a site or group of sites. You will not hear them elsewhere on the same trunked system unless they are out of zone.

Once you (hopefully) repaired & tweaked scanner comes back from Uniden, you might post in the Arizona forum, ro see if anyone has a PRWN file to share. Maybe, for some oddball reason, a slightly different programming approach might work a little better.

 

[Sipho]

BCD396T P25 Audio problems

Thanks for the input. Uniden will receive it sometime on Monday..the 7th of Aug I'm not sure what their turnaround is. I hope not very long. Since then I've been surfing the Forum and found some discussion that is getting me confused. One says that any time there is anolog included with the system to program it as a Motorola Type II system. Also another post said that it might be listed as Motorola P25 and to program it as a Motorola Type II system as well. They said there were very few true pure P25 systems. So now I'm not sure what to think. I guess I will wait and see what Uniden has to say and what they find. Then go from there. Thanks for the input and I will post again once I find out anything. I will also post on the AZ Forum. Thanks again.

 

[rdale]

Those are CQPSK systems, all scanners have significant issues with CQPSK unless you have an incredibly strong signal. And I mean within 2-3 miles from the tower at the most, without much interference from the other towers... Nothing you can do except try to find a perfect spot for the antenna, but if it works for one it may not for another!

 

[Sipho]

Thanks for the information... I might just have to live with it. I read a rumor that the whole Phoenix trunk system is not doing well. The fire dept went back to analog until 2011 because they had trouble inside buildings. So it said... that would be good news to me and then I would not have to hassle bad audio. My BCD396T just got to Uniden for repair today. Hope their turn around is not slow. I miss the little burger already.

thanks for all of the information guys.

Bill

 

[ppmd]

Wondering what happened to Sipho

Sipho,

Did you ever get your 396T to work with Gilbert? I am also in Gilbert, and just bought the 396T. Reception of the P25 system in Gilbert / Mesa is horrible. I used stock antenna, Radio Shack 800 MHz (slight improvement, but not much), and a small mag mount for the car. The reception is really spotty.

I have tried various settings for the P25 on Manual, Default, and Auto. I turned the squelch all the to zero. Still the reception sucks.

I have the latest firmware.

I have searched the Net and this Forum for answers, and probably read every one. No solution so far.

Wondering what you ever did with your scanner. I am ready to throw in the towel.

 

[N_Jay]

Simulcast systems are hard to receive if you are outside the area they are designed to cover.

How is analog reception, maybe your antenna or line is bad?