Choppy P25 Signal on Pro-197 and Pro-106 - PLEASE HELP

[SCPD]

Hello Gang,

I have been messing with a brand new Pro197 for a week now... The P25 digital system that I have programmed in is very choppy. I have only the control channel for Butler County and Sedgwick County, Kansas programmed in the thing, and the signal strength is a full 5 bars. I have set TGRP's and have set the Wildcard and it doesn't matter. Have also tried some things from Radioreference.com, such as setting system to Roam and Stationary, turning on Digita AGC and Turning on "Check All CC" to no avail. Also have downloaded the programming stuff from rr.

When the 197 is on the system it seems as though it is not decoding correctly. It stops on the TGRP's and sometimes opens up on them, but it is always very choppy. Once in a great while, I will get a good strong lock, but rarely. I am running on a Kansas State 800 MHz digital simulcast system and I am sure the control channel is correct. It is also not a priority issue. I was running into the same problem with Pro-106's that I was programming... On my 996XT, there is an RSSI setting that is deep in the software that I changed to make it pickup better and it does not seem to have the problem the RS does...

I am less than 5 miles from one of our sites and we have tried several different antennas too.

Please - any help at all??? I have a Uniden 996XT and it does not do this???

THanks
Chad

 

[ST-Bob]

All digital comms are more subject to multipath interference than analog comms. When you are not moving you may have a stable enough signal to decode the digital system but once you start moving it'll drop out unless you're in a VERY strong signal area. Digital is an 'all or nothing' proposition and can be affected much more severely by multipath or weak signals than analog. This is often a reason for arguments over whether digital systems have more, less or the same effective range as older analog systems.

The manufacturer of course loves to point out the fact that the comms are 100% clear all the way to the maximum range which, for a stationary user, can be even greater than the acceptable audio static limit for an equivalent analog radio. This is pure salesmanship on the manufacturer's part in my opinion. You can generally make out what's being said in fringe areas on an analog radio system well outside the 'acceptable static' areas they state in their literature while you will get NOTHING on the digital system.

Moving the vehicle on a digital system brings you in and out of stronger and weaker reception zones which, on an analog system, makes noises which the human ear and brain can filter out. Result is you still can make out the comms well enough to get the message. Digital radios, however, lose the whole message or just get stuttering bits and pieces of it. This is probably what you're hearing.

The solution may be as simple as a good outdoor reception antenna. Or it could be a complicated as moving your desired reception area to somewhere else.

Welcome to 21st century comms. Might be better off going back to tin cans and string.

 

[ThinBlueLine22]

I am not familiar with the system you are monitoring, but in Minnesota there have been people that have problems monitoring a multi-site simulcast system. They receive the same signal from multiple towers and it causes something similar to what you have described...If you look around in the Minnesota forum, you may find the explanation there and what, if anything, you can do to negate the issue.

 

[garikfox]

Make sure there isnt any metal near the antenna, at least 2 antenna lengths from it.

Mine does the same thing when I place my Pro-197 near the window in my room.

 

[broonzbane]

Have you upgraded your firmware? Not sure if it will make a difference, but it's worth a shot. Go to the Wiki for the firmware upgrades (there are 2).

broonzbane

 

[Astrak]

What ST bob said is correct, scanner's are horrible with simulcast P25 and multipath interference. Your best bet is to start moving the scanner around to find a "sweet spot", there isn't much changing the settings will do.

 

[fmon]

Those 5 bars could be overload on front end. Try ATT.

 

[ind224]

Simulcast is a well known problem. When you have a TG being received press F2 and then F3. Now you can scroll through your CC's (arrow up or down) to see what CC gives you the best decode %.

My experience (3 106's and a 600) indicates you need 95% or better for good decoding.

As others have said, too much signal or not enough...you only want one site hitting the radio if possible.
Here in Indy folks are using beams,stubbies and incremental location changes as possible fixes.
For our MECA system I must have 5 bars to keep from dropping the audio..it is worse during the female automated fire dispatches.

These radios are very sensitive to abuse/dropping. After having two 106's sent in for alignment the difference was night and day.

I also know of a specific 600 that would not do P25 out of the box.

You seem to have tried all the tricks...check your decode percentage and shoot for high 90's.
Good luck!!

 

[SCPD]

Thanks for the replies thus far. I checked the analyze and am running 99% on one control channel and 92% on a second. I have tried entering only the 99% control channel and it works part of the time, and part of the time is still choppy. I am thinking I am not impressed with RS and may take this back and get the 996XT that I know works....

 

[ST-Bob]

It's probably not the scanner's fault but the fact that you have either inadequate signal or signal bouncing off of metal objects causing "multi-path" reception. Digital comms cannot tolerate multi-path.

No other brand scanner will be that much different in the same area with the same antenna IMHO. It's the technology, not the radio or the manufacturer. Digital is different than anything you've ever heard before. My suggestion is to get used to it and do whatever you can (and should) do to improve reception.

Just think how the public safety officers feel when they walk into your house and their hand-helds stop working... Warm and fuzzy ain't it, that's for sure.

 

[akaLTD]

I'm experiencing the same problem and like you have tried a lot of different things. I can tell you after listening to mine breaking up for several weeks it is very annoying & frustrating. Mine doesn't sound like it breaks up as bad as yours but it seems to do it at the most inopportune time and I end up missing some key pieces of information. I've got it working a bit better today but that could just be due to the atmospheric conditions.

I bought mine used and I can't take it back so I have no choice but to deal with it. And & it's not so bad that I'm real unhappy with it but if I'd bought it new, I would have taken it back & tried the Uniden. All I can say if you're unhappy with it now you'll probably be even more unhappy after listening to it for a few weeks constantly tinkering with it & only getting it marginally better if at all ... especially since your Uniden doesn't break up & works just fine.

 

[SCPD]

It actually belongs to a friend, but he is taking it back. I understand all the simulcast/digital 800 stuff and problems noted, but honestly - I have a 996xt and have had it for over a year with NO problem at all, on the same system in the same area. I had a 996t before that and it worked great. I have programed half a dozen 106's in the last week and they are better than this 197, but still not a Uniden. Sorry all you RS fans, but I think the Uniden is a better product - at least on our system.

 

[W6KRU]

It actually belongs to a friend, but he is taking it back. I understand all the simulcast/digital 800 stuff and problems noted, but honestly - I have a 996xt and have had it for over a year with NO problem at all, on the same system in the same area. I had a 996t before that and it worked great. I have programed half a dozen 106's in the last week and they are better than this 197, but still not a Uniden. Sorry all you RS fans, but I think the Uniden is a better product - at least on our system.

It's a good thing you put in that qualifier or I would have to take exception to your post. :lol: I have two 396s and a PSR-500 which is the same as a PRO-106. My 3966XT is lousy on the local simulcast system. With manual P25 adjustment my 396T is slightly better than the 396XT using the forced auto adjustment of P25. The PSR-500 kicks them both to the curb with ease.

I like the 396s features and the storage capability of the XT is awesome but the crappy decoding drives me nuts. As was said above they usually choose to go digital at the most inopportune times.

 

[broonzbane]

I mentioned the firmware upgrade because I was getting distorted (not encrypted) audio from some of the transmissions on the local APCO-25 system here in SE TN/NW GA. Upgrading the DSP firmware solved the problem.

But this does sound like a signal strength issue...

broonzbane

 

[datainmotion]

I'll have to agree with a couple posters here. Simulcast systems can be the bane of any scanner. But, having said that, my GRE 500 works better than my 996 when I am monitoring simulcast sites while mobile. My 197 seems to do well *where it is physically located*, but I have never had it in the truck where the 996 resides, to compare.

 

[Astrak]

Just think how the public safety officers feel when they walk into your house and their hand-helds stop working... Warm and fuzzy ain't it, that's for sure.

More than likely they wouldn't have any problems, a Motorola is a lot better than a scanner on a simulcast system.

 

[W6KRU]

More than likely they wouldn't have any problems, a Motorola is a lot better than a scanner on a simulcast system.

Better but not perfect by a long shot. I hear quite a few of the "unit xxx 10-9 you were digital" messages from the dispatchers. The portables seem to be more prone to do this but the mobiles have their issues in some locations as well. This will obviously vary by system and field locations.

 

[akaLTD]

I also occasionally get the "unit xxx repeat your traffic you're 10-1" .. sometimes they just say you broke up which always makes me laugh since it's one of the few times it didn't break up on my scanner.

And we do still have some areas that aren't covered very good even on their radios. Heard one the other day say he couldn't get out on the radio & couldn't get cell signal either.

Even with the breaking up problems I still like my 106. I like the button layout and the features plus the price was a big factor at the time. I still wonder how the 396xt would do in my area but for less than 1/2 the cost I'm still satisfied with my 106. For all I know the 396xt might be worse.

Mine is still doing better today so maybe some combination adjusting the expert settings might have helped.

 

[w2txb]

Think of the "chopping" of the signal as similar to that which occasionally happens with a cell phone in a marginal coverage area. The signals are sent and received in much the same way. Sometimes the problem is caused by "multipath", sometimes it is caused by being in an "RF Ghetto". A digital signal is either there or it is not - the nature of the beast - when it is good, it is very good; when it is bad, all bets are off.

 

[krokus]

I can vouch for that. My PSR-500 has issues with dropout, when sitting right next to the XTS-5000 I have been issued.

The scanner is trying to make the best of a taxing situation. If you use it on one place, most of the time, I would suggest a fixed antenna for those times. It would help.