Uniden BCD436HP issues for Charlottesville/Albemarle?

[stollings]

To the fellow members of this forum please forgive me if this had already been discussed here but I am a new premium member. I came here looking for answers so hope someone can help me to start listening again.

I have been listening to my scanner for a while now and was monitoring the P16 system. I received a lot of radio traffic on the P16 system without issue. I regularly update my scanner using the Uniden Sentinel software which I understand gets it's information from this site, correct me if I'm wrong. It is my understanding that Charlottesville/Albemarle just recently moved to the P25 system. My scanner is scanning the P25 system (East, West, Scottsville) and I do get occasional radio traffic coming through such as ACPD, CPD, UPD and Fire Dispatch but I seem to have lost all access to the school traffic I listened to. My scanner doesn't pick up half the traffic it once did. When I try to update the firmware and the database on the Sentinel software it says I have the latest updates.

I recently found on a Facebook a link to a scanner page named rdio.eastrivanna.com and when I listen on my smartphone and/or my computer the radio traffic is very frequent and picks up everything that I used to receive on the P16 system. I can have my smartphone and my scanner side by side and the app on the phone is going off like crazy but the scanner isn't picking up half of what the scanner app is picking up even though it says its scanning P25 East, West and Scottsville.

Can someone help me with where my problem(s) may lie? Is it possible that the Uniden Sentinel software still hasn't been updated completely with the current and new Frequencies and talkgroups for the area and time should fix that? Thanks for all your help and apologies again if this issue has already been addressed. I always use the easy update option using the sentinel software and has always proven successful my knowledge of going in and manually setting parameters is limited. Thanks again.

 

[Whiskey3JMC]

My money is on simulcast distortion since the P25 system you mentioned carries the same traffic on the same frequencies across multiple sites at the same time which causes most scanners to lock up & miss transmissions. You can try the mitigation methods mentoned in the wiki I linked but they work in very few cases. Ultimately you'd be better off with a Uniden SDS100 to monitor simulcast systems. Welcome to the RR forums!

 

[dave3825]

If the system is simulcast, you most likely will have issues with that scanner. There are many threads about X36 scanners and simulcast distortion. You can play around with different antenna and even try one with low or zero gain. The person streaming the system is most likely using either an SDS series scanner or and sdr dongle.

 

[jeepsandradios]

I would also limit your scan to the closest simulcast cell to you. If your in the east only scan east. Rest of time its searching for control data.

 

[mc48]

P25 audio decode level adjustment - The RadioReference Wiki

Easier to Read BCD436/536HP Digital Scanner Manual (marksscanners.com)

Just monitor the nearest site and make sure you have all the frequencies in red on the database page entered in.
Since all the frequencies listed are red this may be a Harris system and they are difficult for the 436 to handle, mine works good at times and other times its junk, my SDS-100's and 200 handle it great. In Sentinel I set the sites to manual threshold mode level 8 and it seems to help.
You should also verify that you have the correct service types turned on.

 

[TJX400]

Ideally, you're going to want an SDS100/SDS200. They're the only scanners that're capable of decoding linear simulcast modulation appropriately. While, yes, in certain conditions your BCD436HP may be able to decode some traffic from the closest site, it's highly unlikely you'll be able to get a consistent decode of the system with it.

 

[fredva]

The posts above are correct. The SDS series of scanners was developed after the x36 series and was built to handle P25 simulcast systems that the x36 (and every other scanner on the market) couldn't reliably decode.

 

[KT4HX]

As the above mentioned this is the result of the simulcast structure of the Harris P25 system now in use for Albemarle/Charlottesville. I monitor this system when I am passing through Charlottesville back and forth to our second property in Highland County. However, I am using the Uniden SDS200 and have no issues receiving traffic on the P25 system.

I have attached a screen shot from the database for this system and you can see that the East and West sites are listed as simulcast, meaning you are receiving the same transmissions from both sites. The SDS200 is built specifically to handle this type of "multi-cast", locking onto the strongest of the multiple sites. Unfortunately the 436 is not designed to handle simulcast, and results can be variable as mentioned above. I would employ the tips suggested by the others to see if that helps you get cleaner reception. You may also wish to read this thread about the same issue: TRX-1 Quit receiving Albemarle Co While this is about the Whistler TRX-1, the principle is the same. Hope everyone's input is helpful to you.

 

[stollings]

I wanted to write and thank everyone for the responses I have received regarding my issues. The consensus is that I have simulcast distortion and should look at getting at SDS100 or 200. What I don't understand is P16 was simulcast as well and didn't have any issues. The 436HP wasn't a cheap radio and neither is the SDS 100 or 200. With all these police departments and other agencies going to encryption it may just be just as well to hold on to the 436HP and just pick up what I can receive and just listen to everything else online on PC or the scanner app I have on my phone. I don't really want to invest in an SDS100 only to have for a short time and then they encrypt and be obsolete. I even looked into the Uniden website and found they had a trade-in option but they only offer a value of $150 on a trade which doesn't seem quite adequate for a radio I paid over $550 for. May have to face reality that with the advancement of radio technology and encryption my days of being a scanner enthusiasts may be coming to an end. Thank all for all your help.

 

[N4VKF]

P16 systems are analog trunking, so you would not have the issues with digital distortion.

 

[dave3825]

What I don't understand is P16 was simulcast as well and didn't have any issues.

P16 systems are analog trunking, so you would not have the issues with digital distortion.

I have a 436 and while in my area it does well, it does struggle with simulcast distortion in other areas running analog trunked systems. Not just digital.

 

[Brales60]

and neither is the SDS 100 or 200.

They're worth it, believe me.

 

[jeepsandradios]

I run the 436 on a P2 system with no issues. Its all where your located. Clean up your programming and use a rubber duck or scanner mounted antenna and you may be fine. The biggest fix is hearing only one site.

 

[fredva]

The reason that they are named East Simulcast and West Simulcast is that each site has multiple transmitters spread out over an area using the same frequencies. In a simulcast system, a "site" is not a single location with a single transmitter. If both East and West sites consisted of a single transmitter using different sets of frequencies, there wouldn't be a problem with distortion, even if they are carrying the same traffic.

you can see that the East and West sites are listed as simulcast, meaning you are receiving the same transmissions from both sites. The SDS200 is built specifically to handle this type of "multi-cast", locking onto the strongest of the multiple sites.

EDIT: I'm attaching a map showing the four transmitters for the West Simulcast site. They all transmit on the same frequency at the same time. That's the problem for scanners not built to handle that. The East Simulcast site has the same issue.

 

[fredva]

Delete.

 

[wthclt]

Does anyone in the Charlottesville/Albemarle are have a profile set with the 436 that does somewhat effectively receive the P25 sites that they would be willing to share? I know the SDS is the preferred scanner for this but I am specifically asking about the 436/536. I also realize that location is a key factor and what works for one may not work for all but I feel I am just missing some settings. Thank you in advance.

 

[tvengr]

Does anyone in the Charlottesville/Albemarle are have a profile set with the 436 that does somewhat effectively receive the P25 sites that they would be willing to share?

I may not be in the Charlottesville/Albemarle area but give this hpe favorites list file a try anyway. Save the attached zipped file to your computer and extract. Go to the File tab in Sentinel and click on Import from hpe file (Favorites List). Click on New Favorites List and name it Albemarle Co VA Click on OK. In the Downloads folder, open the extracted file (Albemarle Co VA.hpe). It will appear as a favorites list in Sentinel. Quick keys as follows:

FAVORITES LIST QUICK KEY:
0. Albemarle Co VA
SYSTEM QUICK KEY:
0. Albemarle Co VA
DEPARTMENT/SITE QUICK KEYS:
0. Albemarle Co Interop
1. Albemarle Co Fire/EMS
2. Albemarle Co Fire Misc
3. Albemarle Co EMS/Hosp
4. Albemarle Co Police
5. Albemarle Co Sheriff
6. Charlottesville Police
7. Charlottesville Sheriff
8. University of Virginia
9. Scottsville (Site)
SYSTEM QUICK KEY:
1. VA STARS
DEPARTMENT QUICK KEYS:
0. VA State Police
1. Ches Bay Bridge-Tunnel
2. Dept of Transportation
3. Dept of Motor Vehicles
4. VA Capitol Police
5. VA Port Authority
6. Dept of Emergency Mgmt
7. Dept of Fire Programs
8. Dept of Health
9. Dept of Environment Qual
10. Dept of Military Affairs
11. Dept of Mines
12. Dept of Forestry
13. Marine Resources Comm
14. Dept Conservation & Rec
15. Dept Wildlife Resources
16. Alcoholic Beverage Ctrl
17. Dept of Corrections
18. Dept of Juv Justice
19. Interop/Mutual Aid
20. Mobile Site
21. Radio Techs

 

[mc48]

Just a thought but why have a Q-key for the site if you only have one? No key will turn the site on with the system and then there is no chance of accidentally turning off the site.

 

[tvengr]

There are 3 sites. The Albemarle East Simulcast and Albemarle West Simulcast sites have no quick keys and will be active all of the time. The Scottsville site has a quick key so that it can be turned on and off as needed. Scottsville appears to be a minor fill-in site.

RFSS	Site	Name	County	Freqs
5 (5)	001 (1)	Scottsville	Albemarle	851.125c	852.425c	854.6375c
10 (A)	010 (A)	East Simulcast	Albemarle	851.4375c	851.975c	852.3125c	852.4625c	852.8875c	853.8875c	857.7375c
				858.7375c	859.7375c
30 (1E)	030 (1E)	West Simulcast	Albemarle	852.3625c	852.975c	853.0375c	854.9625c	855.1125c	857.0625c	858.0875c

 

[wthclt]

Thanks, I will give that a shot. I am familiar with creating lists and uploading them and also doing zip code/service type but not completely clear on the nuances of adjusting other profile and favorites list settings...and fear i may be turning something off or not making the correct adjustments.