796D p25 audio problem

[fosters]

Hi everyone,
Been out of the loop for a while, and probably my problem has been answered on this forum before, but so much excellent info here, can't find my solution. Here is the problem or question. I have a 796D and the audio from analog to P25 is annoyingly different. If I set the volume for analog, when astro chimes in it blows my eardrums out. Is there a firmware upgrade or something to make both the volume controls the same. New job, many hours, not scan time hopefully til now.

Thanks and this is an awesome cite for info, keep up the good work!!!!!!!!

Forsters

 

[dfw1417]

Upgrade to 396 or 996

The solution is to upgrade to the 396 or 996 which has AGC.

 

[fosters]

Thanks, but back to the newbee thing what is AGC?

fosters

 

[TBerry]

Try this

I'll try to help you out without telling you to go out and buy a new scanner. The 796D is a wonderful scanner.
During your scanning mode and when you stop on a P25 channel your having sound problems with...Press hold...During that or further transmissions....Press and hold the "9" button...This will take you into the "Sound Quality Mode" Screen.....You'll have Low Med and Upp adjustments....You can manual adjust with your VFO knob......Or you can press the "PRI" key and it will go into auto tuniing...This will take 3 tests of the transmissions then give you an average for that channel...You can then press enter to hold that adjustment to memory...Note this will adjust all sound quality for all P25 channels at one time...I do not believe you can adjust for each channel.....When your done just hit "RSM" then back to scan.

Todd

 

[GTO_04]

I'll try to help you out without telling you to go out and buy a new scanner. The 796D is a wonderful scanner.
During your scanning mode and when you stop on a P25 channel your having sound problems with...Press hold...During that or further transmissions....Press and hold the "9" button...This will take you into the "Sound Quality Mode" Screen.....You'll have Low Med and Upp adjustments....You can manual adjust with your VFO knob......Or you can press the "PRI" key and it will go into auto tuniing...This will take 3 tests of the transmissions then give you an average for that channel...You can then press enter to hold that adjustment to memory...Note this will adjust all sound quality for all P25 channels at one time...I do not believe you can adjust for each channel.....When your done just hit "RSM" then back to scan.

Todd

That will not do anything to help with the variation in volume between analog and digital systems. The cheapest fix is to use an older, cheaper scanner to monitor the analog systems and use the 796 for the digital systems. The 796 is a pretty good digital scanner, but it lacks the automatic gain control (AGC) that evens out the volume differences between the analog and digital systems. Needless to say, I'm glad I kept my 780 when I got my 796!

GTO_04

 

[TBerry]

Well I guess that is all in the opinion...I've found that a clearer signal has given a much more even voice level with proper ajdustment.......Maybe we can wait for some feedback.....I also have a 780 along side my 796.
Todd

 

[MacombMonitor]

Well I guess that is all in the opinion...I've found that a clearer signal has given a much more even voice level with proper ajdustment.......Maybe we can wait for some feedback......So to each there own.
Todd

GTO_04 is correct. They are two different issues. The problem fosters is describing is due to the lack of AGC on the BC796D. I've owned several BC796D's, as well as the hand-held equivalent, the BC296D, and they all had the same problem. Adjusting the APCO-25 characteristics as you describe will have no affect on the audio level when you're experiencing this problem. Where I live (Macomb County, Michigan), Chesterfield PD, and only one of the Mich. State Police talk-groups had this problem.

The issue has also plagued the BCD396T to some extent, although I think Uniden cleaned it up some with the last firmware release. The newest BCD996T handles the AGC issue almost as good as the Radio Shack (GRE) PRO-96/PRO-2096. It's unlikely there will be a firmware update to resolve the AGC issue in the earlier generation Unidens such as the BC796D. After awhile, you learned to live with it.

 

[TBerry]

That's funny because when I first tuned into a digital signal I had the same problem...Here in California San Mateo County...But after adjustment with my sound quality I haven't had that problem....The voice output sounds different on digital but not a large difference in volume...I'd be happy to send a sound clip to show you if you like.....No Volume diff just more bass tone on digital.
Todd

 

[MacombMonitor]

That's funny because when I first tuned into a digital signal I had the same problem...Here in California San Mateo County...But after adjustment with my sound quality I haven't had that problem....The voice output sounds different on digital but not a large difference in volume...I'd be happy to send a sound clip to show you if you like.....No Volume diff just more bass tone on digital.
Todd

I went back and re-read the original post. If the problem is a difference in audio volume between analog, a P25 and all digital comms, not just some, then I might agree.

I was thinking he was having a large variation in audio volume between various P25 digital channels. That was the problem I was having, and describing.

 

[GTO_04]

I went back and re-read the original post. If the problem is a difference in audio volume between analog, a P25 and all digital comms, not just some, then I might agree.

I was thinking he was having a large variation in audio volume between various P25 digital channels. That was the problem I was having, and describing.

Interesting discussion. I'm open minded and will try again to adjust the audio. The digital audio seems clear, just very loud. But........there is a difference in audio volume between analog and all digital communications (Indiana SAFE-T). So maybe TBerry is onto something. It's certainly worth a try. The digital audio is so loud compared to analog it would make a great alarm clock!

I do agree that the 396 firmware upgrade made a huge improvement in AGC. I still get some "machine gunning" but it is not happening on a consistent basis. The 796 never had AGC in the first place so I would not expect Uniden to add it to an older model via firmware upgrade. It may not even be possible to do so.

GTO_04

 

[SCPD]

Well I guess that is all in the opinion...I've found that a clearer signal has given a much more even voice level with proper ajdustment.......Maybe we can wait for some feedback.....I also have a 780 along side my 796.
Todd

The amplitude of the recovered analog audio from a P25 signal is not affected by the BER of the received signal, or the "quality" settings.

Older astro systems which use DSP6 do not support TX AGC. The result is garbage audio for all listeners, including system users and scanner hobbyists. The signal strength DOES NOT affect volume.

 

[TBerry]

The amplitude of the recovered analog audio from a P25 signal is not affected by the BER of the received signal, or the "quality" settings.

Older astro systems which use DSP6 do not support TX AGC. The result is garbage audio for all listeners, including system users and scanner hobbyists. The signal strength DOES NOT affect volume.

Shaun,
Okay let's see if I understand this correctly.....We can shine up the TURD all we want but in the end it's still a TURD?

 

[SCPD]

Shaun,
Okay let's see if I understand this correctly.....We can shine up the TURD all we want but in the end it's still a TURD?

Yes, pretty much.

DSP6 (IMBE codec) is CRAP. No matter what Uniden or GRE does to fix the problem, on the receiving end (your scanner) it will always sound like crap. AGC just controls the super loud talkers, and brings up the audio from the people who are too lazy to take the mic off the clip in the car.

In Motorola's latest release (DSP7 for the XTS5000/SR 6.0 radios, DSP8 for older XTS3000/Digital Spectra/Saber series) the audio quality is much improved, and the AGC feauture is supported in the matching host firmware.

If you want, blame all of the horrible audio issues on Motorola, not the scanner manufacturers. Motorola is greedy and won't provide the firmware updates to their customers for free, even though they're the ones who released the bad/buggy code in the first place over 10 years ago.

Shaun

 

[fosters]

Tberry and all,
Tried the trick you mentioned last night. It may be my imagination, but it seemed to atleast even out a bit between the analog and the P25 digital. The Digital transmissions are still significantly louder, but it seems slightly better. It is atleast a good trick to know. Don't remember seeing that in the manual which is alittle odd. Here in NH, it's about a 60/40 split between digital and analog usage. All the state agencies use the digital, but alot of the towns and fire rescue can't or haven't upgraded yet, so I get alot of what I think you all refer to as "mixed mode" which makes it hard to dedicate 1 scanner to digital and one to analog, atleast for me.
I am thinking about possibly getting the new 996, but if the same audio problem is still present on that scanner, I may have a hard time talking the girlfriend into the deal. Part of my plan of attack on that is the solution to the above problem, which annoys her.

Thanks again for all the help!
Fosters

 

[MacombMonitor]

I am thinking about possibly getting the new 996, but if the same audio problem is still present on that scanner, I may have a hard time talking the girlfriend into the deal. Part of my plan of attack on that is the solution to the above problem, which annoys her.
Fosters

What? Get the scanner...get rid of the girlfriend! :roll:

 

[n8chb]

Hi everyone,
Been out of the loop for a while, and probably my problem has been answered on this forum before, but so much excellent info here, can't find my solution. Here is the problem or question. I have a 796D and the audio from analog to P25 is annoyingly different. If I set the volume for analog, when astro chimes in it blows my eardrums out. Is there a firmware upgrade or something to make both the volume controls the same. New job, many hours, not scan time hopefully til now.

Thanks and this is an awesome cite for info, keep up the good work!!!!!!!!

Forsters

Good question but not sure what you mean about annoyingly different?

The width of the audio on narrow band is very differant than the wide settings of am and fm but voice transmissions can be heard much clearer and understud a whole lot better.

Com systems are not designed for listening pleasure.

One thing I have noticed since the change to digital is less and less times the dispatchers have to ask for folks to repeate messages. That is because they are hearing everything much clearer.

73,

Roger

 

[fosters]

Hadn't noticed that til you mentioned it. Your right I think, alot less requests for repeat of transmissions. Definitely more clear transmissions on digital. The annoying part is I will set the volume to listen to a fire for instance, analog, and then the scanner will switch to a State PD transmission and be significantly louder. I have kinda gotten use to it, she is normally a good sport, but it does bother her from time to time. She actually said I could get the new 996 this morning, but I may wait to see if all the bugs are worked out including this issue. I don't really need the GPS feature, never go mobile just use it as a base, with my Nil-jon outside ant. The GPS feature seems to be the big selling point on the new one. Also, it will probably cost me more in the long run that just the $500 buck if you know what I mean.

Fosters

 

[SCPD]

Roger:

You need to listen to a Motorola ASTRO DSP6-based system without AGC to get a sample of what some poor scanner users have to put up with.

DSP6 systems are so bad, that even some real Motorola equipment has been damaged by the excessively loud audio levels. You turn up your speaker to hear the idiot that doesn't know how to speak into a microphone properly, only to get pounded by a guy replying who is literally eating his microphone. It's not the same as analog where it sounds "a little louder". The difference is HUGE on digital. So much so that the speaker can pop, and needs to be replaced.

Unfortunately I do not have any DSP6 radios around here at the moment, but next time one does come in, I will make some audio samples for you guys so you can get a feel for just how bad the problem really is.

 

[RISC777]

fosters - AGC

Thanks, but back to the newbee thing what is AGC?

fosters

I didn't see your question specifically addressed / answered, so -

AGC is a setting (in the BCD396T) that "helps balance the audio level you hear as you listen to different radio sources so you can hear them at a similar volume."