Problem with reception on a bcd996t

[tx]

Hi everyone

Recently I became the proud new owner of a bcd996t. I really like this radio and it has lots of neat features but I'm having an awful time picking up full transmissions. I have two p25 sites programmed for two local counties and all the transmissions i pick up from police/ems is choppy as if there some horrible interference. I have set the waiting time for p25 sites and messed with attenuation and threshold levels but nothing seems to help. These signals are strong, and originating from the county I live in.

I went to radio shack today and bought a new multiband ground antenna with a 50ohm bnc whip to replace the stock telescoping one, but transmissions are still impossible to understand. I dug out my old Pro-29 handheld from long ago and to my disbelief it does not display the same audio problems my bearcat does on analog channels.

Anyone have any ideas?? I'm can't figure out what I'm doing wrong with this scanner.

 

[ka3jjz]

There are several possibilities here; however I would start by doing 3 things;

a. Going to the database (the link is in the blue toolbar under the logo) and supplying the URLs for the 2 systems you are trying to hear. Since you mention you have sites, I wonder if you have a problem with simulcast distortion, which is discussed here (anything in blue is a link)

http://wiki.radioreference.com/index.php/Simulcast_digital_distortion

There's also the possibility that the systems are not truly P25. If the database says 'Analog and APCO-25 Common Air Interface' they are not. Set your P25 detect to auto and let the 996 do the work. That's the point where adjusting things like the levels and others can make a difference

b. If you haven't already, upgrade the firmware to the latest version which does improve the quality of the digital decoding. It's a somewhat convoluted process, unfortunately, and it does require some level of attention to detail - DON'T skip any steps or shortcut anything. You will need to connect the 996 to the PC, and have a good Unzipper program (WinZip is the clear champ but there are many freeware ones, too). Here is the link to those instructions

http://info.uniden.com/twiki/bin/view/UnidenMan4/BCD996TFirmwareUpdate

c. Go to your user panel (click on 'account' on the very top blue toolbar) and supply the county/state where you are. That way folks more local to you might be able to answer your questions. You might get some better information in your state's forum, where other listeners with the same issue might have some answers (don't just repost the same details - be sure to be a bit more detailed, supply where you are and be sure to supply the URLs from the database, otherwise you'll just get asked the same questions all over again...) 73 Mike

 

[tx]

Thanks for the response! These are the two sites I'm attempting to listen to. Both sites are listed as Analog and APOC25 in the database.

Scanner Frequencies: Loudoun County Trunking System, Ashburn, Virginia
Scanner Frequencies: Fairfax County Services Trunking System, Fairfax County, Virginia

The simulcast distortion description sounds exactly like what I'm experiencing. I had these sites set to P25 Auto previously, but the problem persisted so I set the threshold manually to the value where I saw the lowest error rates. That made things a tiny bit better but not a whole lot.

I'm upgraded to firmware 3_02_00 on my scanner which is the latest uniden's site lists. The upgrade went smooth, no errors. I didn't notice any huge difference after the upgrade either.

 

[ka3jjz]

Did you program these systems as P25 (wrong) or Moto type 2 (right)? That will make a difference in the decode quality.

I would also suggest posting in the Virginia forum and see if others have different solutions. 73 Mike

 

[tx]

Both sites are set to Moto Type 2. I should mention on the 996 this issue also happens on AM channels, like the air band, where I'm not sure if decoding comes into play. But I can clearly hear air traffic control at the local airport on my old radioshack pro29, and the new antenna noticeably improves reception on that scanner.

I don't suppose anything like computer speakers or a network switch or my computer itself might be causing some local interference? Or maybe I just have a bad unit?

I'll pop into the VA forum and see if anyone there has similar issues too.

Thanks

 

[foxtrotyankee]

You want them set at Moto 2 , they are not true P-25 systems , they are using a interface.

 

[tx]

I recorded a short 30second sample of the kind of disturbance I'm hearing. You can listen to it on the link below.

drop.io lcems42

 

[UPMan]

You have Close Call priority turned on. (From your discussion, I was looking for "horrible interference noises" so almost missed that what you were getting was the audio dropping out every 2 seconds.)

 

[tx]

Brilliant!!! Thanks a million! I turned off CC priority and WX priority and I'm no longer getting the skips in audio.