Apco P25 does not work

[eggs4lunch1]

I have a new BCD396T and am still learning how to program it properly. I am trying to scan the Apco P25 Simi Valley, California PD frequencies listed here: http://www.radioreference.com/modules.php?name=RR&aid=629

I have programmed all of the P25 frequencies into a new Motorola P25 system in the scanner. I get nothing except that the signal strength meter flashes occasionally showing anywhere from a couple or bars to full signal strength. Even when the signal strength meter shows full strength, the SCANNER DOES NOT STOP ITS SCAN AND I GET NOT AUDIO.

I also programmed these same frequencies into a conventional system as a test. On the conventional system the scanner stops when a strong P25 broadcast is received. I can hear these broadcasts, but the P25 channels sound like the speaker is in the bottom of a well. When I receive a strong signal on the conventional system on a P25 channel, the screen displays "P25" on the 4th line. Sometimes the scan will stop on a weak signal, and I will be able to hear the start of a conversation which is then lost or is very garbled. When this occurs, the scanner sometimes displays "ENC" in place of the "P25."

I have the following settings in the scanner:

CTCSS search off
No channels are locked out
The system is not locked out
Modulation is set to auto
Data skip is off
Channel delay time is 2 seconds
System hold time is 2 seconds
Apco P25 Threshold is set to auto
Group Qkeys are enabled
ID search/scan is set to search
I-call is set to off
Attenuator is off
Mode (Trunk) is set to auto
Alert tone is off
Alert level is set to auto
Status bit is set to ignore
End code is set to ignore
Emergency alert is off
C-CH ONLY is off
The P25 trunk frequencies have been entered

I have not entered any Band Plan. Does this need to be done and if so how?

Any ideas as to what I am doing incorrectly?

Thanks for your help.

 

[UPMan]

That is not an APCO 25 Trunked system. For conventional (not trunked) digital, just program the frequencies into a conventional system.

 

[hankv]

When I receive a strong signal on the conventional system on a P25 channel, the screen displays "P25" on the 4th line. Sometimes the scan will stop on a weak signal, and I will be able to hear the start of a conversation which is then lost or is very garbled. When this occurs, the scanner sometimes displays "ENC" in place of the "P25."
.

ENC as in encrypted

 

[ChrisE_STB]

I have a Few Simi Valley officers as friends, and I have been told, that its "Dispatchers Choice" to run encryption on Channel one, and one of them Loves it, I think hes on Day Watch. check after 1900 hrs.


Chris

 

[eggs4lunch1]

Thanks for the information. I do not understand why when I program the frequencies as a CONVENTIONAL system the audio sounds like it's coming from a speaker at the bottom of a well. When I use the same system with the same settings and I receive a normal signal, like from the Simi Valley TownCenter (private security on 463.2625) it sounds very normal as do all the other local frequencies on this and other systems I have programed into the scanner. Is there something I have set improperly that causes the Simi PD UNTRUNKED APCO 25 system to sound wierd on a conventional system?

Thanks,

Roger

 

[UPMan]

You might be able to optimize the P25 threshold and improve this, but it is more likely signal quality. Even when received well, digital will sound significantly different than analog. When reception is not good, digital "artifacts" in the audio erode audio quality much more significantly than reception issues on analog.

 

[allen2]

I get the same problem with SVPD

The P25 transmissions from SVPD sound really bad but everything else sounds good. Even LAPD p25 sounds better and it's further away. I've tried adjusting the p25 level but I think it's best left on auto. I'm going to try building a better antenna outside and see if that does the trick.

 

[SegmentFault]

I live in T.O and SVPD does fine. The audio quality of IMBE Digital in my opinion is a lot better than analog audio due to it's superior audio reconsruction capabilities. What may be a problem for you is if you live in the fringe areas where you start introducing bit errors to the data stream due to weak signals. When this occur, it sounds like a broken record that just skpped a bunch of tracks.

Both LAPD (NAC 466) and SVPD (NAC 465) are conventional as peopel have mentioned. The only thing that I can get to from my T.O. location is West Valley/Van Nuys Division due to the mountain ranges in the way. The audio quality of LAPD's transmission is a lot better in my opinion that LAPD.

I have noticed some of the SVPD leadership using ADP based encryption on SVPD Dispatch. I have never heard SVPD dispatch originate encryption. I do hear quite a bit of encryption on SVPD's tactical digital frequencies.

 

[fire-medic8104]

I am having the same problem with mine. I can receive conventional channels fine, but P25 channels don't receive at all. Even if you just hold on one channel, I can receive it on a Motorola Astro, but not on the BCD996XT. I have been beating my head against a brick wall for the last four days and haven't been able to figure out what I am doing wrong. I know for a fact the frequencies and NAC codes listed on radioreference are right because I have them programmed into my Astro.

Does this sound like the problem you are having or are you receiving some P25?

 

[ka3jjz]

Without seeing the programming it's hard to say - did you, by chance, define the P25 channels with a PL? That won't work - either use no tone, or set up a NAC. 73 Mike

 

[fire-medic8104]

No, I put it under a conventional system, left the PL blank and put the NAC in. Left modulation on auto, attenuator off, audio type all. Under the system, I set analog and digital AGC on. I am not sure what else to do.

 

[fire-medic8104]

How do you adjust the p25 settings? I followed the information I have and pushed the channel select for function, pushed volume, then can't figure out which to turn or push to adjust the setting.

 

[RoninJoliet]

Set it to "digital Only??...Also , try programming it W/O the NAC??

 

[fire-medic8104]

Neither of those work, so I don't have an idea.

 

[ka3jjz]

Truly the only way to really figure this out is to dump the programming and post it here. Otherwise it's all pot shots in the dark. 73 Mike

 

[fire-medic8104]

Is there a way to save and post it, or I can email the profile.

 

[ka3jjz]

When you reply, look about 2/3 way down, for a button called 'Manage Attachments'. Click on that and follow the prompts. Zip (compress) your file and let folks know which program you are using (for the XT models, it's either FreeScan, ProScan or ARC XT). It would also be helpful if you supplied the URL of the system you are trying to receive from our database.

73 Mike

 

[fire-medic8104]

Ok, here it is, using ARCXT Pro.

Here is the link to what I am programming.
Department of Public Safety (DPS) Scanner Frequencies and Radio Frequency Reference