Digital decode observations

[ButchGone]

I have a 396t and have noticed a big difference in the way it hears 3600 baud "mixed mode" systems vs. 9600 P25 systems. Both are 800Mhz and simulcast from four sites.
On the mixed mode SmartZone system is hears very well and decodes digital groups with no problems. And it works well driving around in the car, even around most cell sites. It's the latest firmware version.
The 9600 P25 system is different. Sitting still on my desk it works fantastic, 0% error rate, smooth sounding audio. But when I drive around it's another story. I notice the "DAT" icon blinks on and off, and stays off when I'm anywhere near cell sites. That's also when it does not decode anything. But the signal strength indicator shows good signals, most bars and I see the CC freq displayed. What gives?
At best when driving the audio is choppy, at worst it just isn't there. Does the 396 just not have the ability to decode P25 properly when moving around? The P25 system is brand new.
The mixed mode 3600 baud system works flawlessly, analog and digital no matter if I'm moving, near a cell site, etc. Go figure?
BG..

 

[Danny6569]

396 t

the 396 t does not have the capability to decode better than the newer 396 xt, the reason for that is because with the 396 xt you can change the channel to digital only which allows you to drop the end noise for one, and with the newer radio you can make a lot more adjustments to the digital systems than you can with the 396 t, such as P-25 adjustment mode and the P-25 lp filter and also has a setting for the P-25 adjust level mode, some of these setting can really help make the radio sound a lot better than the 396 t, ive had the 396 t before myself and compared to the 2, the newer 396 xt sounds like it decodes a lot better overall.

 

[N_Jay]

Th lower speed control channel is a lot easier to simulcast than the high speed.

You may also be observing differences between the systems in layout and coverage and not just simulcast differences.

 

[Frankenstein106]

try using a 700 mhz antenna.I made one and finds it works a lil better than the scanner antenna.What city are you in cause i find in new orleans on the P25 system reception is not quite the supposed 25 mile site range,even using a roof mount 1/4 wave antenna,you also have to consider site antenna location and whats between you and it,like buildings.I just wonder how the P25 system would work on UHF.

 

[RoninJoliet]

Mr. Frankenstein that is very good information, here on the ILL-P25-Starcom Digital System some folks are banging there heads on the wall cause of "multipath problems and like you said "path" problems...I been preaching and writing this also cause i have a Site only 4miles away but in the path of being in a hole and that tower even close is very bad while two towers on a even curve of the earth give me excellent coverage and are 24 miles away......Ron in Joliet