ProVoice Simulcast Distortion

I’m curious if anyone is experiencing ProVoice simulcast distortion. All of the P25 simulcast systems I listen to are plagued by simulcast distortion.

The ProVoice system that I am most familiar with is in Lincoln, NE. It is a two-site simulcast system and is a mixed mode EDACS Analog/ProVoice system. The system is flawless with Analog with no simulcast distortion. I have never monitored ProVoice on this system, but I will be passing through over Christmas and will get a little monitoring time. I will likely not have time to test in areas that have overlapping coverage of the transmitters.

I’m guessing there are other ProVoice simulcast systems, and now that we can decode ProVoice, I am curious if anyone is having simulcast distortion issues, and how it compares to P25 simulcast.

Hello,

I have a three site simulcast system here and have not had any problems so far. I am within a couple of miles of one of the towers.

Provoice uses 9600 FSK, so it is not as complex as P25.

73 Eric

I suspect that like all other simulcast systems, system setup and location will affect performance.

It's works great in Lincoln. Error rate 0-3

Well since a lot of the simulcast problems begin due to poor control channel decode, you won't have to worry about that (assuming it already works well with analog EDACS).

Anyways, any new updates in this regard? I'm trying to decide whether to buy ProVoice. Everywhere I may use it will be simulcast.

Has there been as many pre-releases with the ProVoice as there has been with the DMR? It seems 1 firmware update and it was there, I don't know how to setup ProVoice


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I've got the upgrade for ProVoice


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enosjones said:

Has there been as many pre-releases with the ProVoice as there has been with the DMR? It seems 1 firmware update and it was there, I don't know how to setup ProVoice

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They did not do a pre-release of the ProVoice update to the general public. This was limited to internal beta testers only. The DMR update is the first beta/pre-release version that has been made available to the general public.

To verify that provoice is installed on the scanner correctly do this:
Menu
Settings
Upgrade
Upgrade ProVoice

You should see "ProVoice has already been activated." If you see something different or don't have "Upgrade ProVoice" under settings, refer to instructions for installing ProVoice key.

Once you have the key installed, for unencrypted ProVoice talkgroups on an EDACS system you will hear audio. You will either need to have the Talkgroup programmed if you are in ID Scan Mode, or be in ID Search mode without the talkgroup locked out. It works just like a mixed mode Motorola Type II systems with both Analog and P25 Digital talkgroups.

I added to this thread at risk of being off topic. If you need further assistance with ProVoice, I suggest opening another thread as this has noting to do with ProVoice Simulcast Distortion.

Back to ProVoice Simulcast Distortion...

Cellphone, how did it do in NE?

AggieCon said:

Cellphone, how did it do in NE?

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Where I was used the radio, it was great audio! I have only been in Lincoln, NE twice since my original post and I have not had a chance to monitor any other systems. I did minimal monitoring while I was there, but I hold on the system did recordings that I could share. I was never in any area of the city where there would have been overlap between the two transmitters, so I might not be a good reference for potential simulcast distortion. I'm hoping someone else that uses the radio on a regular basis on a simulcast system can provide a better review of simulcast performance.

AggieCon said:

Well since a lot of the simulcast problems begin due to poor control channel decode...

Click to expand...

The problem starts way before the 'poor control channel decode'. It has to do with the the discriminator tap...

Yes, that's what I've been saying as well. Let me be more elaborate:

You have a simulcast EDACS and a simulcast P25 system on the same towers. Your consumer radio decodes the simulcast EDACS control channel with no problem; however, the P25 simulcast control channel decode is intermittent. This means that you always pickup an EDACS call instantly, but you might enter late (or miss altogether) to many of the P25 simulcast calls due to the poor decode rate.

So, digital voice decoding aside, if EDACS control decode is more reliable than P25 control decode, you're automatically going to have fewer problems receiving ProVoice than P25 digital (because you don't have to worry if you are missing or coming late to a call).

Then it comes down to how the radio does with the voice decode in simulcast. I was just ruling out one major issue faced with simulcast reception.

By the way, I'm one of the main ones spreading the info about the discriminator and simulcast, if you review the posts. I don't have solid documentation on this, but would appreciate anything that someone may have available.

AggieCon said:

... I don't have solid documentation on this, but would appreciate anything that someone may have available.

Click to expand...

Look at the components of the wave form being used for simulcast. CQPSK, WCQPSK ect. compared to C4FM. Then look at what the receiver outputs to the next stage.

AggieCon said:

By the way, I'm one of the main ones spreading the info about the discriminator and simulcast, if you review the posts. I don't have solid documentation on this, but would appreciate anything that someone may have available.

Click to expand...

LMFAO.. That's rich...:roll:

Haha glad I gave you your evening laugh. I'm serious, the technical documentation is hard to find. If I am wrong, correct me with evidence. This is an online forum not a peer reviewed journal. Wow.

If you realized how ridiculous your statement was, you'd have the same reaction. You think this is something that's just popped up recently, and you've discovered the cause?? This crap has been going on for years now with these scanners. It's been discussed MANY times on these forums. The manufactures just don't give a ****. Bells and whistles are what sells around here...

I know the information is scarce, and there is a damn good reason for it too. All these different modulation schemes are PROPITIATORY! You will find bits and pieces in some patent grants, but you need to be skilled in the art to understand them.

As far as the OP's question, you're not likely to have many issues like you might encounter with simulcast P25 systems. ProVoice uses a run of the mill 4-GFSK, constant envelope scheme. Scanner filers are good enough to smooth the wave form. Same thing for DMR(GFSK, constant envelope)..

Of course I don't think that. And I bet I've read dang near every post on the topic on this entire forum. There's a lot of various "theories" about this on RR and I was just letting him know that I am on the same page.

The bottom line here is, they(Uniden/Whistler) don't seem to have any intention or incentive to properly fix the issue. There is no one here that can change that, other than to quit buying this crap, which is exactly what I've done. The fortunate thing for them though, is that many people buy these things not knowing they aren't very good. That kind of offsets those of us who know better.

Absolutely. And I think you saw my post explaining the economics why. By the way, my (forthcoming) video comparing the two scanners also compares vs OP25. Hopefully that sort of visual will help people understand.

However, here's how it usually goes:

"Hey I bought this expensive scanner now how to I ... (for instance: receive my local simulcast system)"

Instead of:

"Hey I want to receive my local radio system, what equipment do I need to do that best?"