U4 Bit Errors Detected SBS/ABC

[malibu91]

Hi all,

My U4 has been displaying the below graphic in the last 2 days. I have never seen this before.



The picture breaks up very badly, however I seem
To have good signal level and quality?

Does anyone know what this could mean?

Cheers
Jules

[Gully]

What skin and firmware version are you using?

[MrQuade]

Looks like OverlayHD based on the "Bit errors detected" message. That's not present on the standard skins.

If you are getting bit errors, I would expect to see the Q value dropping lower than 100%, so I am confused too.
Having the S value at 93% is also good in that it shows the tuner isn't being overdriven by too much signal.

Is it present on all tuners, or do you only see that on Tuner D? I see that D is in use in the provided screenshot.
Are the tuners daisy chained together, or do you split externally?

[malibu91]

After a bit of messing around I can report the following.

1/ It only does it when all four tuners are being used. Example is recordings on 7,9 and 10 and viewing on SBS or ABC.

2/ It is only present when the three tuners recording are the internal ones and the fourth tuner being watched is the USB tuner.

3/ The message/ error occurs using either the stock USB tuner or the “bluey” regardless of whether the USB extension is being used or not.

Curious?

[malibu91]

I am using the latest firmware, updated last night via live update to pick up on the new picons, so 19.3?

Tuners are attached as per the user manual and yes Overlay HD.

The issue only occurs when viewing the channel being serviced by the USB tuner

[MrQuade]

Tuners are attached as per the user manual and yes Overlay HD.

The issue only occurs when viewing the channel being serviced by the USB tuner

The manual's hookup method is a daisy chain.

Try temporarily plugging tuner D into the antenna directly, or via an external splitter and see if the problem goes away.

[malibu91]

Is there a way to do this without a splitter as it needs to be using 3 services to record whilst viewing the USB tuner to recreate the issue?

[prl]

Does it happen on a particular tuner slot?

The screenshot shows tuner D in use for live TV (coloured green). Tuner D is the USB tuner: tuners A-C are built in. Does the problem happen consistently on the USB tuner slot (whichever USB tuner is in use), or does it sometimes only happen on built-in tuners, too?

It's possible that the USB tuners don't report correct signal quality (signal-to-noise ratio).

Bit errors (BER - Bit Error Rate) are detected further down the processing pipeline when the Forward Error Correction in the signal data is processed. The BER reported in the firmware is the error rate after error correction, so errors here will be reflected in actual problems with the data stream: audio glitches, pixelation or missing EPG or other data stream metadata.

I think that the BER reported is errors/sec, and you get the warning in the OvetlayHD skin at 375. That level is likely to be accompanied by easily detected visual or audible problems.

19.3 isn't a firmware version: it's a family of firmware versions, though what you're running is probably version 20191106 (MENU>Info>About>Revision).

[MrQuade]

Is there a way to do this without a splitter as it needs to be using 3 services to record whilst viewing the USB tuner to recreate the issue?

You can set tuner D to be the preferred tuner, and it will use that without needing to occupy the other tuners.

Do that via the setup menu under Tuners.

[Grumpy_Geoff]

Do that via the setup menu under Tuners.

... and then after that zap to a different broadcaster than currently in use, as this'll force a retune and use of the preferred tuner.

[Grumpy_Geoff]

Set the USB as the preferred tuner and switch to it as advised.
Then open OpenWebif (http://beyonwizu4/), select Television >> Current. What's reported under the 'Tuner Signal' heading for SNR and BER?

[malibu91]

Hmmmmm not sure that will help.

It only occurs when

1/ A,B and C tuners are being used for recordings.
2/ Tuner D (USB tuner) is being watched.

If I stop one of the three active recordings and then view content using viewing tuner D, the issue is not there.

In short the USB tuner is throwing errors only when all four tuners are being used.
Using 20191106 version firmware.

[malibu91]

Set the USB as the preferred tuner and switch to it as advised.
Then open OpenWebif (http://beyonwizu4/), select Television >> Current. What's reported under the 'Tuner Signal' heading for SNR and BER?

I'll give this a go now.

Thanks

[prl]

1/ A,B and C tuners are being used for recordings.
2/ Tuner D (USB tuner) is being watched.

Are you certain about that? What if tuners B, C and D are used for recording and tuner A is for live TV? Is live TV OK? Is the recording made on tuner D unwatchable? Or something else?

[malibu91]

OK, setting the USB tuner as preferred has caused massive picture breakup, and the red error message too.
Interesting. This is with zero recordings being undertaken and only the USB tuner in use.

Results are as below as per Grumpy Geoff's advice.

Tuner Type: DVB-T Tuner Number: 3 Tuner Signal Quality SNR: 100
Tuner Signal Quality SNR_DB: 27.29 dB Tuner Signal Power AGC: 94 Tuner Bit Error Rate BER: 0

[MrQuade]

Hmmmmm not sure that will help.

It only occurs when

If I stop one of the three active recordings and then view content using viewing tuner D, the issue is not there.

In short the USB tuner is throwing errors only when all four tuners are being used.

This kind of detailed info is very handy to provide in the first post if you have already performed good diagnostics . Saves us annoying you with questions .

You can also selectively disable tuners to see what effect it has.

Say disable tuner C, then start recordings on A and B, then see what D does.

Also, does it matter what services the other tuners are tuned to? ie. could we be getting strange intermodulation interference.

I am inclined to simply recommend you buy a cheap splitter from Bunnings and just split the signal from the antenna and send one leg to Tuner A/B, and the other to tuner C. That should bypass any issues inherited from upstream tuners.

[Grumpy_Geoff]

OK, setting the USB tuner as preferred has caused massive picture breakup, and the red error message too.
Interesting. This is with zero recordings being undertaken and only the USB tuner in use.

Standard Beyonwiz MINI DVB-T tuner or the Realtek "bluey"?
Timeshifting enabled?

Results are as below as per Grumpy Geoff's advice.

Tuner Type: DVB-T Tuner Number: 3 Tuner Signal Quality SNR: 100
Tuner Signal Quality SNR_DB: 27.29 dB Tuner Signal Power AGC: 94 Tuner Bit Error Rate BER: 0

I don't pretend to know if the SNR figure is low or not (mine is higher, > 29 dB, varies if you keep clicking 'Current')

[malibu91]

Either, I have both the standard tuner and the Bluey.

Wife is shooting sideways glances at me because her show is about to start recording, so I guess I'll have to pick up later.
Thanks so much for the help

Jules

[Paul_oz53]

Hi malibu91,

The USB tuners are not as sensitive as the inbuilt tuners in the U4. I use OverlayHD. In certain atmospheric conditions I get the same bit errors - on channel 7 in particular. This occurs in dense rain and light wispy cloud conditions but not otherwise with an active splitter. Without the active splitter, I lose all the channels.

The bluey is better than the default unit but can still breakup with a weak signal.

Personally, I doubt a passive splitter will work for you but they are cheap. As noted, I use active splitters and they greatly improved my reception but they are not for everyone. If you are in a strong signal area an active splitter may overload the tuners input so it is best to tread carefully before spending money on a powered active splitter.

[Brainz]

The USB tuners are not as sensitive as the inbuilt tuners in the U4. I use OverlayHD. In certain atmospheric conditions I get the same bit errors - on channel 7 in particular. This occurs in dense rain and light wispy cloud conditions but not otherwise with an active splitter. Without the active splitter, I lose all the channels.

The bluey is better than the default unit but can still breakup with a weak signal.

I agree. My bluey is much less sensitive than my T2's internal tuners and it has been quite erratic here in Brissie especially during the middle of the day. I had a lot of trouble watching the tennis on 7HD in January.

This said, I had far less trouble with the external tuner when I switched back to 17.5.20190207. This is obviously not recommended for all but I can claim that, having installed 19.3.201901106 at least 5 times since it was released, as is and with restored backups/skins/plugins, it only ever lasted a day before spinning wheels and crashes which on the surface appeared to be caused by the external tuner flaking out. This was also apparent when using the bluey standalone with internal tuners disabled

With the older release it is not perfect, but it is a far sight more stable than 19.3. I wish this was not the case. I don't have the time to run extensive comparisons as it is my only unit. I would need there to be nothing on my record todo list for a couple of days to even attempt it

I vaguely recall Grumpy_Geoff posting something about the bluey being less receptive under 19.3 but I can't find it now.

[MrQuade]

I vaguely recall Grumpy_Geoff posting something about the bluey being less receptive under 19.3 but I can't find it now.

The drivers changed between versions, so there will likely be a difference in performance when that happens.

[Grumpy_Geoff]

I vaguely recall Grumpy_Geoff posting something about the bluey being less receptive under 19.3 but I can't find it now.

I don't think that was me, but Paul_oz53 did say that.

[Paul_oz53]

I vaguely recall Grumpy_Geoff posting something about the bluey being less receptive under 19.3 but I can't find it now.

I don't think that was me, but Paul_oz53 did say that.

Indeed I did. I upped the gain on my active splitter to compensate but haven't really definitively tested the relative performance.

If the U4 gets a bad recording we usually swap to the T4. (I record everything at least twice since I can!). I usually don't bother conducting a post-mortem since it isn't a frequent problem.

[Brainz]

I vaguely recall Grumpy_Geoff posting something about the bluey being less receptive under 19.3 but I can't find it now.

I don't think that was me, but Paul_oz53 did say that.

Indeed I did. I upped the gain on my active splitter to compensate but haven't really definitively tested the relative performance.

If the U4 gets a bad recording we usually swap to the T4. (I record everything at least twice since I can!). I usually don't bother conducting a post-mortem since it isn't a frequent problem.

I knew it had to be one of you two fine gents!

Using 19.3 on the T2 is just not a viable option at the moment as it is used as a fallback device for a increasingly dodgy PC dual tuner setup.

It looks like I may have to move into the roaring '20s and grab a V2!

Cheers

[malibu91]

I wonder if the Hauppage WINTV DualHD tuner might be a more solid option?

[MrQuade]

I wonder if the Hauppage WINTV DualHD tuner might be a more solid option?

Only the V2 can accept a Dual USB tuner.