Oklahoma City EDACS activity

[mam1081]

There is lots of activity today in ProVoice!!

Records 800 division is now using ProVoice to dispatch. You can hear the decoded ProVoice back on analog VHF still. Units seem to have slight difficulty understanding the dispatcher on analog. The console is LID #9983. I wonder how their numbering scheme with consoles will be.

 

[woodyrr]

I am hearing analog activity on TG 04-022 Sunday morning. I hear the fire alarms and the dispatcher audio, but not the apparatus. I suspect that this is a simulcast of 155.055.

 

[ttlradioman]

I talked to an officer yesterday. He gets his new handheld on the 17th.

 

[dstew67]

I am hearing analog activity on TG 04-022 Sunday morning. I hear the fire alarms and the dispatcher audio, but not the apparatus. I suspect that this is a simulcast of 155.055.

I heard that as well. I submitted it before I saw this post, so I hope I didn't steal your thunder. You are correct, that it's a simulcast of 155.055

 

[woodyrr]

I heard that as well. I submitted it before I saw this post, so I hope I didn't steal your thunder. You are correct, that it's a simulcast of 155.055

There is certainly no thunder to steal. I just posted the information to give others who might be on another system or scanning OKC EDACS rather than searching an opportunity to listen and verify a Talkgroup that suddenly turned up that isn't listed in the database.

 

[mam1081]

Did you submit it? The Database is only as good as people make it.

 

[dstew67]

yeppers....submitted, and already updated

 

[Gilligan]

I didn't realize the EDACS Records channel was Provoice, but I did notice that the conventional channel seemed muffled. It sounded like the modulation was turned up too much. Must have been the Provoice changing the audio.

 

[woodyrr]

I've been listening to the VHF records channel (151.310) and I am wondering why the officers in the field using the VHF system sound so much better than the records clerk using ProVoice. My instinct tells me that the ProVoice audio even converted to analog should be at least as good over the VHF system as that of the VHF radios. I hope for the sake of the people who are going to have to use this system, that the ProVoice audio is losing something in the translation to analog.

I did some monitoring of the Grand Prairie, TX APCO P25 system before Christmas, and was rather dissappointed with the quality of that audio as well. Perhaps it sounds better using a dedicated commercial grade radio.

I guess that it is a sign of things to come that since the records clerk is ProVoice, her audio doesn't come across when I'm listening to the EDACS system. I wonder if as more and more EDACS radios come online, the system will imperceptibly get quieter and quieter until all of the traffic is gone.

 

[mam1081]

Not that there wouldn't be any activity - just that a scaner wouldn't pick up any of the activity. I'm pretty sure all the city servises will be in analog even after the switch, so you'll have something to listen to.

 

[dstew67]

...My instinct tells me that the ProVoice audio even converted to analog should be at least as good over the VHF system as that of the VHF radios...

You're instincts are right....but not completely. Anyone else can add to what I'm saying here and confirm or offer other thoughts. I'm sure that the issue with voice quality is compounded by a couple things:

1. First, analog ALWAYS sounds better than digital. True audiophiles always prefer a vinyl record over a cd. You always loose something in digital sound.

2. The second compounding factor is relaying analog signals. One of the nice things about digital is that even though you loose some "roundness" of sound, transmitting and receiving digital audio does not further contribute to loss. Because, when the signal is there, you're simply relaying digital information (packets, just like on the internet). Almost all the information has to get there, or else the signal doesn't get translated back to alalog properly in the receiver and the signal "drops out". This is why new cell phones will sometimes "drop" part of the conversation completely, rather than you hearing static. Analog signals will always loose information right from the start. This is why when you're close to a signal source it's very clear, and as you move further away you hear it less clearly.

What's happening with the simulcast is the digital signal is converted to analog, then sent to a series of repeaters, then sent to the car radio (our your scanner). In a nutshell, there's a lot of room for potential loss. When everyone's listening to a digital signal, there's going to be better quality audio coming from the speakers.

 

[K5MAR]

1. First, analog ALWAYS sounds better than digital.

Dave , gonna disagree with you on this. The quality of the sound will depend on various factors such a the conversion algorithim used, sampling rate, etc. Digital sound can be much superior to analog, if the digital system is of high quality and the analog system isn't.

True audiophiles always prefer a vinyl record over a cd. You always loose something in digital sound.

What's been shown in blind tests is that the audiophiles who insist that they can tell the difference between vinyl and CDs, (or tube vs. solid state, or regular wires vs. "oxygen-free" cables) is that they can't determine which is which, and are as likely to choose the "bad" as the "good". Now, I admit when the first CDs came out, the quality was not as good as vinyl. They were often thrown together from whatever was at hand, sometimes from the raw session tapes rather than the "masters". But current CDs are of much better quality, properly mixed. (The original "Dark Side Of The Moon" CD, compared with the current CD, is a case in point.)

Now, as for the problems with the OKC system, I haven't heard it, so I can't say. However, as the crosspatch is temporary, I suspect the setup probably leaves alot to be desired. "Quick and dirty" would likely be an apt description of what is being used. Why spend alot in a setup that will be gone in a year or so.

Mark S.

 

[dstew67]

Interesting thoughts, Mark. Thanks for adding them. Would you agree though that, given equal quality in equipment, power, line of sight, etc., an analog signal will sound better?

On being able to tell the analog and digital quality, I swear that I can tell 2% and whole milk apart ;-)

P.S. I agree that the most likely cause of the degradation in quality is the "quick and dirty" temporary simulcasting setup.

 

[woodyrr]

Oops! I certainly didn't intend to start a "spirited discussion". I don't want to veer too much off topic, but I don't mind admitting that I'm having a great deal of difficulty coming to grips with some of this. As far as trunking and digital Public Safety communications are concerned, I am a lot like Rip Van Winkle wakening from a hundred years' sleep. Until very recently, the last time I consulted this superb website, it was called the DFW scanner listener's page or something and was confined to the DFW Metroplex; Trunktracker scanners were new; OHP in OKC had just converted from a Type I TRS to Type II; EDACS was a new and novel unscannable radio system that played the GE jingle after every transmission; and APCO P25 was some wild idea that you read about in "Monitoring Times". While, what possessed Oklahoma City to select an EDACS system (ProVoice or Analog) befuddles me to distraction, I have to say that I am extremely impressed with what I've heard on the OK DPS "statewide" system and with what this website has become. I hope that when the OKC EDACS system is up and running, the audio quality proves to be satisfactory.

 

[mam1081]

woody, you should come to our meeting tonight. I'm sure there will be lots of discussion on the new EDACS stuff.

NE corner of 23rd and Classen in OKC - Chinese Super Buffet!!!

 

[woodyrr]

woody, you should come to our meeting tonight. I'm sure there will be lots of discussion on the new EDACS stuff.

NE corner of 23rd and Classen in OKC - Chinese Super Buffet!!!

Thanks for the invitation.

I can't make it tonight, but i'll watch the thread for the date of the next meeting and tentatively plan to attend if i'm not in Dallas which seems like is most of the time.

Have a good meeting!

 

[mam1081]

Several officers are talking on "Dispatch 6" about the records dispatcher. It seems they have been having problems. She's now using a desktop noise cancelling mic - maybe that will "clear" it up a little.

 

[K5MAR]

Interesting thoughts, Mark. Thanks for adding them. Would you agree though that, given equal quality in equipment, power, line of sight, etc., an analog signal will sound better?

I'd give that a qualified "yes". On the superiority of analog vs. digital audio, remember, companies like Sirius are making good money selling digital audio that is as good as, or superior to analog FM broadcast. I think the problem is where people come from when setting up a radio system. At this point there doesn't seem to be a user demand for superior quality audio on digital systems. It's as though they are conditioned to expect the digital audio to be lower fidelity. When users start demanding better sound from their digital radios, the manufacturers will provide it. This may entail a new APCO standard, I don't know.

Mark S.

 

[mam1081]

OCFD started testing audio on FD Ch 3 today. I just heard them while at lunch. Unit was giving an audio test to dispatch. I didn't think it sounded good, but dispatch could copy - that's what matters, right?

 

[mam1081]

ProVoice testing on TGID 309. Recording going "Radio Test 1 2 3 4 5 6 7" over and over....
Every once in a while, that same radio will goto TGID 1553 (Radio Techs), and do the same thing in analog.

It sure does seem like we've been through this before...