Cobb County P25 on Uniden and GRE video

[b7spectra]

The radio system in question, is the Cobb County DTRS (not analog) multi-site system. I live within 1.2 miles as the crow flies (that's a southern expression for straight line), and with a stock, 800 dedicated and attic antenna and the reception is still the pitts. The ONLY time I receive the Cobb system clearly is when I'm outside of the County at least 5-10 miles from the nearest tower site.

The Metro Atlanta area is covered in DTRS with the exception of the Fulton County analog TRS (which for the age of it, works pretty damn good!). As MTS2000des has told me, Cobb has one of the oldest vocoders compared to all the other DTRS and that could be part of the reception problem. Even with at the County 911 Center (I have had the luxury of sitting with a friend of mine there), the reception is not the greatest.

I'm like everyone else - HOPING that UPman is reading all of this and that this "upgrade" will take care of the problems everyone is having. I can't afford to keep having to buy and sell my scanners just so I can hear my local jurisdiction!

 

[N8IAA]

Hey! No PM talking about me!

The 396 works great on the Fulton Analog system, but that about it. I use it mainly because of the remote head capability. Since I haven't played much with the GRE or PSR, I don't know if they have the remote head capability.

Nope. No PM's about you. GRE is the company, PSR is what's in front of the scanner--PSR-500, PSR-800. Mike, the PSR-900 will be a mobile version of the 800 with a remote head. Still the same MP3 keypad setup. Not good for mobile, unless you just want to listen to all the scanlists, I mean playlists, that are currently running on the scanner.
Larry

 

[troymail]

i would like to say that cobbs p 25 system is way better than the p 25 systems here in south carolina like the one charleston county has if you were to here it on your scanner its so awful you would want to throw it out the window

I'll second that! I was really frustrated trying to listen to the Charleston system in December when I was there -- right downtown and couldn't understand a single thing. It was better when I got out of the city.

 

[t_shuffle]

The conditions do not appear to be the same. There appears to be (in the background) a teddy bear holding the GRE. The Uniden sounded like it was in an echo chamber. If the Uniden was in the same location as the GRE then I would consider it a valid test.

If you honestly attribute all that to a teddy bear, then I'm going to Toys R Us tomorrow and buying a few. I wonder what they do for AM DXing?

 

[kk4eb]

For what it is worth, I live about 1 mile from the Gordy tower site. I get about 99.9% perfect copy of the Cobb DTRS system with my 396XT. I get dropouts on a very infrequent basis - perhaps one or two seconds of speech over several hours of monitoring. My guess is that my QTH is 'shadowed' from the Kennesaw Mtn site, therefore simulcast CQPSK-LSM is not a factor. If however, I move to another location such as the Town Center mall area where I believe signal levels to be about equal between these two sites, then dropouts are frequent. Just wanted to point out that there are conditions where the XT does indeed work well. Looking forward to the update to see if it makes any improvements.

 

[opticalserenity]

Are you talking about Gordy Parkway? If so, I'm pretty close to that. The video was shot close to the intersection of Scufflegrit Road and Sandy Plains Road.

 

[MTS2000des]

The radio system in question, is the Cobb County DTRS (not analog) multi-site system. I live within 1.2 miles as the crow flies (that's a southern expression for straight line), and with a stock, 800 dedicated and attic antenna and the reception is still the pitts. The ONLY time I receive the Cobb system clearly is when I'm outside of the County at least 5-10 miles from the nearest tower site.

The Metro Atlanta area is covered in DTRS with the exception of the Fulton County analog TRS (which for the age of it, works pretty damn good!). As MTS2000des has told me, Cobb has one of the oldest vocoders compared to all the other DTRS and that could be part of the reception problem. Even with at the County 911 Center (I have had the luxury of sitting with a friend of mine there), the reception is not the greatest.

I'm like everyone else - HOPING that UPman is reading all of this and that this "upgrade" will take care of the problems everyone is having. I can't afford to keep having to buy and sell my scanners just so I can hear my local jurisdiction!

Cobb recently pushed new firmware and a system release bump which took care of the rough audio issues, and last summer the FTR's came down and did some fine tuning, so I don't think this is an excuse Uniden or their fanboys can use to defend the poor performance of the 396/996.

Apparently it has to have a PERFECT, distortion free, multipath free signal.
This isn't reality except in a lab.

I had the SAME issues receiving Atlanta's 7.2 simulcast system as Cobb's.
Sure it does great on analog, so does my FT8800R minus trunking decode.

We'll soon see if the touted firmware update solves the problem...the problem some assert doesn't exist.

 

[K4SVT]

Cobb DTRS

seems to me they need to go X2-TDMA that mode is clear as nexedge sounds good most recent FW we have in our radios is 16.00.01...not bad but still seems to have the same issues like D-Star...my base works fine most of the time. but my portable is crap all over the place with dead spots...but just my 2 cents i pick cobb up better on my HP then my county radio..its sad a radio half the money works better...

 

[kk4eb]

>Are you talking about Gordy Parkway? If so, I'm pretty close to that. The video was shot close to the intersection of Scufflegrit Road and Sandy Plains Road.

Correct. If you zoom your location on the attached map, you will see that you are just about midway between the Kenn Mtn and Gordy Parkway sites:
WQHN949 (COBB, COUNTY OF) FCC Callsign Details

This is probably the worst-case situation as you are probably receiving both sites with near-equal signal strengths.

 

[K4SVT]

P25

no i live in acworth now...

 

[ilgrant]

They were in two rooms so the audio would interfere with each other. I wanted the test to be done at the exact same time. Obviously a YouTube comparison video isn't a scientific test, but consider they were both literally 5 feet away from each other.

I don't work for either company, I think they both have a long way to go, so I don't know why you would assume or accuse me of falsifying the data on purpose. Heck I want the radios to work well...if anything, I tried everything I could to make the Uniden perform well. I made sure the firmware was up to date, I even bought a professional 800mhz antenna setup on my vehicle at a public safety radio install shop. They even looked at the radio.

Optical: Where in my statement did I say that there was falsification of data? All I stated was that the conditions were not identical. In my experience a scanner moved 5 feet can make the difference on whether a signal is received or not.

 

[opticalserenity]

Optical: Where in my statement did I say that there was falsification of data? All I stated was that the conditions were not identical. In my experience a scanner moved 5 feet can make the difference on whether a signal is received or not.

I apologize, I misunderstood then. I'll say this though, in the time I had the Uniden, I tried like hell to get it to work correctly. Literally I drove around the county trying to find the sweet spot. Unfortunately, what you see in the video is about the best case scenario for what I experienced.

 

[b7spectra]

kk4eb you live about 1/4 mile from the Gordy site (if the arrl.org site is correct)! I'm over on Steinhauer by Sweat Mtn Park!

 

[ratboy]

I got tired of the annoyingly bad audio on my 396XT and sold it soon after I bought it. I have an HP1 extreme that has suddenly gone deaf, and it sounds better than the 396XT did, but my PSR-500, PRO-106 and 197 sound a whole lot better. The HP-1 wasn't a bad radio, but now it's deaf as a rock. The warranty just expired, of course, so I will probably take a look inside to see if the antenna lead is broken. I hope it doesn't have to go to the black hole, er Uniden Service, where I won't see it for a good while..

 

[ahearn]

Recently purchased a GRE PSR-800, a great radio, but am puzzled with the reception of Cobb County's system. It's a "burbly" or echo type of sound on many transmissions that I know other people have also reported. I'm in Woodstock, probably about 20 miles from the Gordy antenna (don't know where the other antennas are).

It's not the radio because I also sometimes monitor the Cobb system with a a scanner app on my iPhone and iPad, and the "burbly" effect is there too. The person who supplies the feed probably lives in Cobb.

I'm wondering if it's a multi-path effect, possibly created by relatively equal proximity to multiple antennas. I know other people have reported that the problem goes away when they are further away, which makes sense in that the effects of multiple antennas is minimized.

Any comments? Any way of reducing the problem short of moving away?

 

[b7spectra]

It's just the nature of the beast with scanners versus Motorola equipment.

 

[ahearn]

I found that setting attentuation on (either globally or only on the Cobb talkgroup) makes a huge improvement in receiving the system at my location, probably because it allows the stronger signal from the closest tower to dominate. Switching back to the stock antenna from a RS 800 has the same effect.