Need Help Setting Up P25

[slyjoker87]

I recently purchased a Uniden Bearcat bcd325 P2 for my father for father's day. He asked me to get him a new police scanner so he could pick up the digital channels. My father lives in Peoria Illinois which recently switched to digital. I tried setting up the P25 channels using the RR database. I couldn't get it to work on my own so I downloaded freescan and used the import feature, but I am still getting nothing.

I have a suspicion that this problem is related to the fact that my area uses simulcast with a digital system which is causing problems receiving. Some research I've done suggests that this may be a problem, but I am not technically skilled enough to diagnose what is happening or troubleshoot.

Any help and advice is appreciated.

 

[ofd8001]

Yes simulcast systems can be difficult to program and figure out if something doesn't seem to be working.

The first question is: Do you see any type of indication on the signal strength meter? If so simulcast distortion should be suspect. You are getting signal but the scanner is having trouble decoding the signal it receives from the multiple sites.

You can confirm a simulcast distortion problem by taking the scanner to about 1/4 mile of a site. If you hear everything fine there, but audio disappears or gets garbled as you move away, then simulcast distortion is likely.

If you do not get any type of signal strength indication, then you may not have programmed sites correctly.

Also for the very new user, I'd suggest using ID Search mode in the beginning. That way you'll hear everything, giving a comfort level the scanner performs. After you are comfortable the scanner is "working", then switch to ID Scan so all you receive are programmed talkgroups.

 

[darunimal]

Uniden DMA FAQ - The RadioReference Wiki. The first 4 blue texted items under here DMA Scanner Topics and Terms should help, minus the third one.

 

[darunimal]

System, Site w freq's, groups, and TGID's all make up one single Digital System, without one of each you have nothing, nada, zilch Attenuation and or a high Squelch 7-15 would help with Simulcast, maybe even no antenna, but are you even scanning the system/site and group yet. If you have AGC on turn it off

 

[slyjoker87]

So I went for a test drive and I got a pretty good signal when I was right under the tower. It degraded to probably less than 50% about a mile away and by about two miles it was completely dead.

The meter seems to go back and fourth between full and looking for control channel as well, which is odd. Not sure whats going on...

Edit: I also used the software Freescan paired with RR database to make sure my control channel and TGID were set up properly.

 

[ofd8001]

The "dropping down the coming right back" signal strength indication is normal for a trunked system. It's due to some "internal housekeeping" that the scanner does.

So you heard good/clear audio near the site, then as you traveled away about a mile, the audio garbled up and was gone 2 miles away? Sure sounds like simulcast distortion.

There are some things you can try. It's a trial and error situation - make the adjustments, program them and see if you get improvement. Unfortunately it is time consuming to find the right combination, but you probably can obtain some improvement.

Use your FreeScan programming. Navigate to the applicable site. There are some settings you can change and see what happens. Check the 20db Attenuation box, change the APCO modes (Default or Manual). Lastly the treshold (don't go any higher than 15). Obviously remember what you started with so you can restore if needed.

You may have to try some different combinations to see what works best.

 

[slyjoker87]

What if nothing works? Would a different antenna help? Or should I just return it and give up?

(remember its for my dad and he's not want to have a headache trying to get it to work all of the time)

 

[AggieCon]

Try running it with the squelch all the way open/down. Is it going to be primarily stationary, or will he use it on the go? Placement and antenna selection are important. How many control channels and sites did your program? Try a just a single site and the control channel that is actually active.

What exactly does the received audio sound like? Are you getting any audio?

There are ways to improve reception. It takes time and experimentation.

If you want a solution that supports P25 simulcast, you need to look for the Unication G4/G5 or (for much less money) software defined radio and free/cheap software.

If you are using the stock antenna, you should get one tuned to 800 mHz, and, if it will be stationary, I recommend a Yagi.

 

[ofd8001]

As odd as it may sound, a "better" antenna is "worse". The issue is that the scanner is receiving signals from multiple sites. They arrive a little out of sync and the scanner has trouble decoding them.

So the key is "worsening" the reception. Yagi antennas are directional, so they can be pointed to one site, thus reducing signal from other directions. I've seen paper clips used with some decent results.

With this being a simulcast system - multiple sites all using the same frequencies, you cannot "pick and choose" a single site.

My community uses a 13 site simulcast system. The x96 series scanners can be tolerable with adjustments, but not pristine. There are areas where reception is better, usually closer to a site. Perhaps your dad might be in one of the "blessed areas".

I like the x36 series much better. If you got the option of returning it for a 436, that's a thought.

Just out of curiosity, what system are you trying to monitor?

 

[AggieCon]

Even if there is a simulcast site on a system, it does not exclude the possibility of additional "better" sites on a system that a scanner might try to look for, causing problems.

I disagree with the "use a bad antenna" approach. While timing issues are part of the problem, the main reception problem with simulcast systems is that there is a frequency (really Phase Shift) modulation component and an amplitude modulation component to the signal. The consumer scanners aren't good at handling this. Even with a weaker antenna, the scanner will be receiving the same signals in essentially the same proportions. But by utilizing a directional antenna, you modify the ratios: You are now receiving more of the closest and strongest signal compared to everything else that is out of time, primarily due to extreme multipath. My guess is that this approach (maximizing the reception of one strong path) helps the radio achieve stable frequency lock even though the amplitude of the signal changes continuously.

I've never improved performance (of hardware or software scanners) by using worse antennas, but I can usually fix problems by using a better antenna.

 

[ofd8001]

The simulcast system I listen to has 13 sites, all of which transmit on the same frequencies. I'm unaware of how to program my scanner so that it receives only one of them and would welcome any instructions on how to do so.

On the "antenna", once I was monitoring the local system and knew there were active transmissions but I wasn't hearing audio. I removed the scanner antenna and began to hear audio.

http://forums.radioreference.com/radio-shack-scanners/237694-paper-clip-antenna.html

http://forums.radioreference.com/general-scanning-discussion/249889-building-antenna-scan-p25.html

 

[AggieCon]

I am unsure which system you monitor, so I have no idea how many sites it has.

A system consists of 1 or more sites. A system is not simulcast. A site either is or isn't simulcast.

A simulcast site is 1 site.

A simulcast site has 2 or more repeater locations. It sounds like the simulcast site you scan has 13 locations.

A system can have multiple sites that cover a specific geographic area. In fact, there can be multiple simulcast sites covering the same geographic area. This is common in many large urban areas. There can be multiple simulcast and single location sites in the same area. Certain talkgroups might be available on only certain sites. Sometimes this is referred to as "layers."

There is also a "subsystem" organization in between the system and site organization, but I'll leave that alone for now.

I can't speak to your antenna success, and each situation is different. However, the OP indicated he has good luck near the tower and it falls off as he departs. That tells me that he might have luck with an appropriately tuned antenna, ideally with good gain and preferably directional.

http://forums.radioreference.com/mi...forum/331324-simulcast-distortion-buster.html

I use this one: https://www.amazon.com/gp/product/B00L3ZRF9A/ref=oh_aui_detailpage_o05_s01?ie=UTF8&psc=1

 

[ofd8001]

I might be mis-understanding something or we are getting caught up in word nuances. To me a simulcast system is two or more sites, all of which are using/transmitting the same frequencies.

My local system, Louisville MetroSafe Louisville Emergency Communications Network: MetroSafe Trunking System, Multiple, Kentucky - Scanner Frequencies specifically the Jefferson County Simulcast has 13 sites (one isn't listed). As I understand it when a given talkgroup (such as Police 1) is active it is transmitting one the same frequency (such as 859.7625) on all 13 sites.

Simulcast - The RadioReference Wiki

 

[kayn1n32008]

I might be mis-understanding something or we are getting caught up in word nuances. To me a simulcast system is two or more sites, all of which are using/transmitting the same frequencies.

My local system, Louisville MetroSafe Louisville Emergency Communications Network: MetroSafe Trunking System, Multiple, Kentucky - Scanner Frequencies specifically the Jefferson County Simulcast has 13 sites (one isn't listed). As I understand it when a given talkgroup (such as Police 1) is active it is transmitting one the same frequency (such as 859.7625) on all 13 sites.

Simulcast - The RadioReference Wiki

How you describe simulcast system is correct.

 

[AggieCon]

Word nuances, but they are important. Don't blame me. I didn't create the terminology.

The system you monitor has 1 subsystem and 4 sites. You are correct in your understanding for the simulcast site, but in your explanation, replace site with location and system with site.

The point of simulcast is that multiple locations work together on the same frequencies as one site.

It is important to understand this, because it determines how things are programmed and how radio traffic is handled by the trunking controllers.

I think you are saying "site" as in "tower site." But with trunking, the "site" has a technical relevance.

 

[slyjoker87]

As odd as it may sound, a "better" antenna is "worse". The issue is that the scanner is receiving signals from multiple sites. They arrive a little out of sync and the scanner has trouble decoding them.

So the key is "worsening" the reception. Yagi antennas are directional, so they can be pointed to one site, thus reducing signal from other directions. I've seen paper clips used with some decent results.

With this being a simulcast system - multiple sites all using the same frequencies, you cannot "pick and choose" a single site.

My community uses a 13 site simulcast system. The x96 series scanners can be tolerable with adjustments, but not pristine. There are areas where reception is better, usually closer to a site. Perhaps your dad might be in one of the "blessed areas".

I like the x36 series much better. If you got the option of returning it for a 436, that's a thought.

Just out of curiosity, what system are you trying to monitor?

I could try to return it to Amazon and pick up a 436. But is it really going to address the simulcast issue any better?

Also trying to monitor the Peoria, Illinois area public safety channels.

 

[AggieCon]

It could be better on the margin, but it's hard to tell. I suggest posting a thread in the Illinois forum asking about others' success receiving Peoria County, and what equipment they use.

Without understanding your goal, it is hard to help you. Too often, people order a radio and then post on here asking why it's not working. Instead, a better approach is to start off on here, state your goal, and then ask for advisement.

Are you wanting a portable radio to use around town, or will it be used mostly in the home? Or in the vehicle?

What services are you interested in monitoring, specifically? What cities? Fire? Police? Other? Many of the TGs appear to be patched to analog frequencies (might not be true anymore).

Are you interested in airband, military air, CB, ham, businesses, etc. or only the public safety?

If most of the listening will be from a house, how is it situated to the tower locations? Do you have the option for an outside antenna? If not, what is the construction of the house and can you place an antenna on the side closest to the tower? Do you already own antennas that you can use?

At the moment, out-of-the-box scanning is a myth. It takes some time and work, but it is possible to receive most systems well.

No one can tell you whether or not to buy a new radio, but, if you have the money, you can compare the two. One might be a little better. It might even be a lot better. But you're going to be getting into some expensive equipment.

As I previously mentioned

If you want a solution that supports P25 simulcast, you need to look for the Unication G4/G5 or (for much less money) software defined radio and free/cheap software.

The Unication is not that much more than a 436; however, it isn't a consumer type scanner. But if your dad already has one for conventional scanning, that's not an issue. With software defined radio, you can get setup for under $100, assuming you have an appropriate computer, and you will likely have good results.

I want to help you get this to work, but it's going to take work and perhaps some frustration. Also, more information would help.

 

[kayn1n32008]

It could be better on the margin, but it's hard to tell. I suggest posting a thread in the Illinois forum asking about others' success receiving Peoria County, and what equipment they use.

Without understanding your goal, it is hard to help you. Too often, people order a radio and then post on here asking why it's not working. Instead, a better approach is to start off on here, state your goal, and then ask for advisement.

Are you wanting a portable radio to use around town, or will it be used mostly in the home? Or in the vehicle?

What services are you interested in monitoring, specifically? What cities? Fire? Police? Other? Many of the TGs appear to be patched to analog frequencies (might not be true anymore).

Are you interested in airband, military air, CB, ham, businesses, etc. or only the public safety?

If most of the listening will be from a house, how is it situated to the tower locations? Do you have the option for an outside antenna? If not, what is the construction of the house and can you place an antenna on the side closest to the tower? Do you already own antennas that you can use?

At the moment, out-of-the-box scanning is a myth. It takes some time and work, but it is possible to receive most systems well.

No one can tell you whether or not to buy a new radio, but, if you have the money, you can compare the two. One might be a little better. It might even be a lot better. But you're going to be getting into some expensive equipment.

As I previously mentioned



The Unication is not that much more than a 436; however, it isn't a consumer type scanner. But if your dad already has one for conventional scanning, that's not an issue. With software defined radio, you can get setup for under $100, assuming you have an appropriate computer, and you will likely have good results.

I want to help you get this to work, but it's going to take work and perhaps some frustration. Also, more information would help.

Well put. Very good advice