Motorola XTS5000 vs. Uniden Bearcat BCD996T Audio Delay

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JASII

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I brought the Motorola XTS500 from work in the house tonight and I was comparing various aspects and it was interesting to me that when I kept one specific talkgroup locked on manual on the BCD996 and that same talkgroup was the selected priority on the Motorola XTS5000, the audio was always heard first on the Motorola. I think I have the latest firmware in the 996. Maybe this topic has been brought up before, but I don't recall seeing it. Anyway, it did seem that on some very short transmissions that the BCD996 never even heard it.
 

naSTI

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I've compared my EFJ handheld against a 396, 996 and PSR-600 all at the same time on a n APCO-16 Moto Controller and P25 audio channels and the EFJ wins decoding the P25 every time against all the commercial scanners. The dedicated LMR radio is just more agile, period.
 

Palmetto

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Your comparison is instructive, easy to accept, but not unlike driving a Porsche to work, but a Pinto on the weekends. None of these scanners, not the 996 or the 600 nor any of them will perform remotely close to the XTS5000, a very expensive radio. Nonetheless, you're being asked to pay a princely sum for a consumer-hobby radio which tries to cover an extremely wide frequency range with a host of complex features, some bordering on the absurd (GPS?), but winding up with a product which doesn't do its intended digital job very well. Put the XTS5000 up against any scanner on a 9600 digital simulcast system and you'll cringe.

Wouldn't many of you put that five hundred bucks or more into a scanner which was dedicated to the 700/800 band which dropped all the cute stuff for a product which did one job well and without enslaving the user to foolishly complicated controls?
 

PeterGV

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cpuerror said:
Doesnt the XTS cost 3-5k?
Yes, it does. AND it only handles a single band (VHF/UHF/800). AND it'll only scan 16 channels or 10 talkgroups. AND it (the XTS) scans muuuuuch more slowly. AND if you want to put it on a TRS, you'll need the system key from the system's admin.

AND you have to pay for firmware updates to the XTS, including bug fixes (sorry, given the other thread about Uniden firmware updates I couldn't resist).

Though it's not completely clear, I think the OP was asking about audio DELAY, not necessarily about decode quality.

If you stand next to somebody talking on a P25 channel, and listen on your own radio, you'll notice a significant delay from "real time." The encoding/decoding delay is a function of the algorithms and error detection/correction methods that the radio uses... and how these algorithms are balanced between hardware/firmware.

I guess I wouldn't be too surprised to discover that the 396 and the XTS-5K use different decoding methods.

de Peter K1PGV
(owner of both an XTS-5K and a 396t... wouldn't want to give up either one!)
 

naSTI

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Besides the multi-band, multi-mode, no system key required, and costs an eighth of the price of LMR, it is a clear that it wouldn't be practical to use a dedicated LMR radio versus a scanner. It just doesn't make sense unless you are an authorized user of the system and you need to interact with other users of the system.

This is really a moot point, the difference is *NOT THAT* much, that someone would drastically deduce the scanner are useless. We're talking about miliseconds seconds here, not missing every other transmission every time.

However, I can understand that JASII was just trying to point out a fact about the two receiver's performance.
 

garys

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OTOH, when I was in Philadelphia a few years back I had a chance to listen to a PD XTS3500 on their trunked system. The audio from that radio was not noticeably better than the audio on my BC250D.

Gary
 

naSTI

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garys said:
OTOH, when I was in Philadelphia a few years back I had a chance to listen to a PD XTS3500 on their trunked system. The audio from that radio was not noticeably better than the audio on my BC250D.

Gary
LOL!!!! I am listening to Phila PD as I read your reply.. and it still blows, no matter what I listen to it with!!

EDIT: Plus, I very often hear the dispatchers says "Unit XYZ, you're unreadable!" So that pretty much sums it up.
 
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kenisned

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PeterGV said:
If you stand next to somebody talking on a P25 channel, and listen on your own radio, you'll notice a significant delay from "real time." The encoding/decoding delay is a function of the algorithms and error detection/correction methods that the radio uses... and how these algorithms are balanced between hardware/firmware.
A little off topic, but this is an interesting thread and I hope you don't mind.

I have a digital Thales Racal 25. I've noticed on conventional/analog vhf that there is a delay on the Thales compared to the 996.

Even though the channel is programmed as analog, does it still go through the process you describe above and the end result is a slight (very slight) delay. It's almost like an instant echo.
 

naSTI

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The very slight echo will be due to different radio manufacturers use their own implementation of the APCO spec. They will usually have the capability of their own chip manufacturing or a good subcontracting deal to make them. As a result of different clockspeeds and basic implementations will always yield different results.

They are only tied to producing output to the APCO spec. They would rather do that, then license processors from someone else, only the DVSI vocoder. The internal on-chip methods to produce those results vary.

It's no biggie. ;-)
 

slicerwizard

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naSTI said:
The very slight echo will be due to different radio manufacturers use their own implementation of the APCO spec.
The delay on audio channels has nothing to do with APCO; on the Racal 25, analog RX audio is run though a DSP (audio filter) which introduces the delay. The 996 just uses an analog filter, which doesn't introduce any noticeable delay.
 

ResQguy

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garys said:
OTOH, when I was in Philadelphia a few years back I had a chance to listen to a PD XTS3500 on their trunked system. The audio from that radio was not noticeably better than the audio on my BC250D.

Gary
Kinda strage that they would be using a radio that doesn't do trunking OR 800mhz on an 800mhz trunked system...:confused:
 

naSTI

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slicerwizard said:
The delay on audio channels has nothing to do with APCO; on the Racal 25, analog RX audio is run though a DSP (audio filter) which introduces the delay.
Eh?

I am assuming JASII was referring to digital audio. That being the case, the unfiltered, uncorrected, raw RX is passed to a DSP, which among several other things, will pick out the I and Q bits that make up the APCO 25 protocol. The software which is burned into the DSP will internally handle the assembly of those frames slightly differently according to each developer of their respective DSP. I'm sure you knew that already, assuming your username has any bearing on your experience with A/D and D/A conversion.

slicerwizard said:
The 996 just uses an analog filter, which doesn't introduce any noticeable delay.
Since you are referring to analog audio, I can tell you for sure that my EFJ is output audio with a slight delay (maybe like the Racal would?) in comparison to the scanners, because they do use an analog DSP in order to eliminate Squelch Tail Crash which occurs everytime the carrier collapses at the end of each transmission. This is solely to make is easier on the ears of the user.

Is this similar to what you're talking about when you refer to how the Racal operates, slicerwizard?
 

rpgbigman

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Have you compaired it with a Pro 2096?
I have both 996T,Pro 2096, and XTS 2500.
I would say the Radio shack scanner seems to lock up VHF digital as Fast as as my XTS 2500 Radio. and the 996T has always been slow.
I love the Fetures on the 996T but for Week Signals and faster scanning you can't go wrong with the Pro 2096.
Ryan.
 

garys

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ResQguy said:
Kinda strage that they would be using a radio that doesn't do trunking OR 800mhz on an 800mhz trunked system...:confused:
My error, they were XTS3000, not XTS3500. Happy now?

Gary
 
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