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Did new Sky Q LNB impair my DVBViewer reception?


uglyned

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A while ago during an offer we caved in and got Sky.

 

They had to fit a new LNB. It has 8 connections, 4 I think go to the Sky box and another 3 go to my TV box to Blackgold DVB-S2 cards.

 

For years and years I've had Recording Service recording without any reception issues.

 

But now recently I'm getting lots of reception issues. Sometimes DVBViewer can't see the BBC One HD transponder (10847V) at all, Transedit can't scan or analyse it - 0%.

 

At other times it can be patchy with lots of discontinuities, other times it can be perfect for hours on end.

 

When I have 0% reception on this transponder (and a few others around it), other tuners can pick up other channels fine.

 

And the weird thing is, when DVBViewer and Transedit are reporting 0% reception, and can't see the transponder at all, it's absolutely fine on the Sky Q box with no issues at all.

 

Can anyone suggest anything?!

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SkyQ only uses 2 connections. This is why it needs a special LNB - There are 4 permutations - Vertical, Horizontal and Low, High, The SkyQ LNB combines the low and high into one feed, so 1 for vertical, 1 for horizontal. To accommodate your legacy devices they have fitted a hybrid LNB which can supply SkyQ feeds and the normal LNB which is switchable by your devices. It sounds like some of the feeds on the legacy side could be fault. Identify which of the feeds go to the SkyQ and leave them alone.

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As someone who is also interested in SkyQ I have been carrying out some further research into the hybrid LNB. This is available for sale separately but the units I have seen on various sites only offer 6 connections - 2 reserved for SkyQ (thanks Derrick I hadn't heard the "FBC tuner" description before), and the other 4 for legacy devices. Inputting "SkyQ Hybrid LNB" on the Amazon UK site will bring up an example.

Sky do offer an octo LNB for people with multiple devices but this pre-dates the SkyQ box and it is my understanding that this LNB will not support SkyQ.

 

I assume that you have recently upgraded to SkyQ and I expect that Sky would replace any octo LNB with a hybrid LNB.

 

If so, I would agree with Derrick - it sounds like the hybrid section on the LNB is faulty and the entire LNB will have to be changed.

Edited by cp2
typo
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Thank you. That's frustrating!

 

It may be a 6 output hybrid then - I'd assumed that Sky Q had 4 inputs, I think the engineer told me that. Must be wrong.

 

It's not that DVBViewer won't receive those channels at all, it's just very patchy. Whereas before it was absolutely faultless.

 

I checked the signal strength on the Sky Q box and it's not at its highest. Maybe the LNB isn't perfectly aligned, but the Sky Q tuners are a little more sensitive.

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The meters on Sky boxes are not the most reliable measure of signal strength. But you're right it could be alignment. If they haven't relocated the dish it is unlikely to be the actual location of the dish.

Whether it is an LNB fault or misalignment it is still means a call to Sky for an installer visit. I would keep things simple and say you are getting intermittent signal loss without mentioning that it is only on your legacy devices.

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  • 1 month later...

I did manage to get Sky out and they swapped the LNB for another hybrid one but the problem persists.

 

Before the Sky install, the signal strength reported to DVBViewer was always around 66%. Now it can vary - when it's on 66% reception is usually fine but it can drop down to 60% at times and I don't understand why.

 

There's a single LNB strapped to it, receiving 19.2e and that works remarkably well for a zone 1 dish. Then the reception on the Freesat LNB drops, the 19.2e one remains good.

 

But behaviour is really odd.

 

Yesterday, for example, I had no reception on any channel. Recording BBC One HD, just no reception.

But when scanning the 10847V transponder in Trandedit, the results I get are Bloomsberg HD, COLORS HD and DAYSTAR HD. I looked them up, and they're on 11685.5V.

I'm guessing that after a while, reception will come back and the correct channels will start showing up.

I don't think this is a signal strength thing, I think something strange is going on. Can anyone shed any light on it?!

It's not just that transponder either.

Currently scanning 10714H I'd be expecting Channel 4 channels but I'm getting Clubland TV amongst others. That's on 11552.75.

 

If anyone has any suggestions that would be well received.

 

When the installer came to look into it, he swapped the LNB because the old one, he said, was 'dead on transponder 41'.

 

I suspect that the LNB was not faulty, but this was a symptom of whatever the underlying issue is.

 

Edited by uglyned
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I have no idea what's going wrong but the Transedit examples could be explained by wrong IF-band selection in the LNB. A universal LNB works with LOF1 (low band) = 9750MHz and LOF2 (hgh band) 10600MHz.

 

10847V is obviously a low band transponder. IF=10847-9750=1097 [MHz] this is the intermediate frequency that arrives at the tuner and yields a scan with the BBC HD services. If for some reasons the LNB is not in LOF1 mode but LOF2 mode 1097MHz IF translates into 1097+10600= 11697 [MHz]

 

On 11697V is no transponder listed. The tuner will lock to the next available frequency if not too far away. -> 11686V.

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35 minutes ago, Derrick said:

I have no idea what's going wrong but the Transedit examples could be explained by wrong IF-band selection in the LNB. A universal LNB works with LOF1 (low band) = 9750MHz and LOF2 (hgh band) 10600MHz.

 

10847V is obviously a low band transponder. IF=10847-9750=1097 [MHz] this is the intermediate frequency that arrives at the tuner and yields a scan with the BBC HD services. If for some reasons the LNB is not in LOF1 mode but LOF2 mode 1097MHz IF translates into 1097+10600= 11697 [MHz]

 

On 11697V is no transponder listed. The tuner will lock to the next available frequency if not too far away. -> 11686V.

 

Thanks Derrick. But as you said earlier in the thread, we think this is not a universal LNB. It's specific to Sky Q - something you refer to as an FBC tuner.

 

From what I've read on other forums, it's called a 'hybrid' LNB and is supposed to auto detect the type of tuner that's on the end of it and adapt what it sends accordingly.

 

Just, for some reason, something appears to be going wrong.

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Thanks Derrick.

 

Here's a screenshot of the lnb settings, I also attached a support.zip in case you can help.

 

The server that the RS is installed on is not used for watching TV so please ignore anything around rendering, it doesn't usually work but it's not an issue, as I normally access the PC through RDP.

 

lnb.jpg.d545331707a04f04c8868bf5cffb5401.jpg

 

 

 

Edited by uglyned
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Ah right - thanks yep I found them now.

 

To save me copying, pasting, saving, uploading - they're identical to the screenshot you posted - LNB type 'Universal', and the same numbers in those boxes on the right.

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44 minutes ago, Derrick said:

The settings are well hidden

 

There is a main menu item (TV/Radio -> Reception Settings/Channel Search), a gear wheel tool button in the Channel Editor (bottom right) that provides a hint ("Reception Settings"), a help button that opens the corresponding Wiki article, a Reception Settings context menu item...

 

...and there is a "Support for visual impaired users" checkbox on Options -> Extended :)

 

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@uglyned, you have to connect the tuners to an universal LNB. A wideband LNB transmits the entire frequency range (low and high) to the tuner. No switching frequency, no 22KHz anda single LOF. e.g. http://www.inverto.tv/lnb/213/wideband-40mm-lnb-with-horizontalvertical-ports

 

The IF frequency range is 300-2300 MHz which won't work with your devices (normally 950-2150 MHz).

   

 

 

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34 minutes ago, Derrick said:

@uglyned, you have to connect the tuners to an universal LNB. A wideband LNB transmits the entire frequency range (low and high) to the tuner. No switching frequency, no 22KHz anda single LOF. e.g. http://www.inverto.tv/lnb/213/wideband-40mm-lnb-with-horizontalvertical-ports

 

The IF frequency range is 300-2300 MHz which won't work with your devices (normally 950-2150 MHz).

 

   

 

 

 

 

Thanks Derrick - but it's a hybrid LNB, so it's supposed to autodetect the tuner type and respond correctly.

 

I realise this is a really strange one, and thanks for your time and effort in explaining.

 

You are correct - when the subscription runs out, it's likely that I'll put the old universal LNB back up - I did keep it. I have no doubt that this will resolve the issue, I just wanted to try and get them both working together.

 

Thanks again.

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2 hours ago, Derrick said:

How should that work???

 

Sorry - maybe I'm wrong, maybe there are 2 dedicated connections for Sky Q then 4 legacy connections. I'm afraid I don't understand enough about it to know for certain, and there's not much documentation about it on the internet as it's so new.

 

I found this, which seems to be the best technical explanation.

 

http://www.satcure.co.uk/tech/SkyQ.htm

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Zitat

..maybe there are 2 dedicated connections for Sky Q then 4 legacy connections.

That seems to be the case. The 2 wideband connections (H and V) are for the FBC (Full Band Capture) tuner. They can't be used in connection wit DVBV. Btw. there are no FBC-tuners yet on a PC card. The 4 legacy connections represent in fact a Quad LNB.

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Out of interest, I just did one last test.

 

I shared the LNB feeds between DVBViewer RS and a new install of MediaPortal I did for a test.

 

I tried recording Channel 4 HD this morning on DVBViewer RS and it had no bitrate - the recording time increased, but nothing was recorded.

 

I tried recording Channel 4 HD at the same time on MediaPortal and it records fine, with no discontinuities.

 

Same Channel 4 HD, same transponder, same computer, same Blackgold DVB-S2 cards.

 

It was in the middle of the recorded show, so even though I do have PDC enabled in DVBViewer, the programme was on at that point.

 

I'm going to swap the tuners around now and see if the result is the same.

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So I swapped the tuners. Stopped both recordings, gave the DVBViewer tuner to MP and the MP one to DVBV.

 

This time, both recordings worked without fault.

 

So my layman's impression of what's going on there is that

  • MP can grab, lock and use an LNB feed as before. Once it has it, it keeps it.
  • DVBV can use an LNB feed if it is already correctly locked, but it can't keep hold of it, so if an outside factor changes the polarity, position, whatever it is of the LNB, DVBViewer simply loses its lock and can't get it back

This, to me, looks like an issue with DVBViewer.

 

However, I think it's quite unlikely that there will be a large number of people in the UK, using DVBViewer RS, and Sky Q with a hybrid LNB, so even if you agree that it's an issue, I can understand that it may not be high on your list of prioirities to resolve.

 

I was thinking about this the other day - it must be 10 years since I got my first DVB-S card and started streaming TV through my PC. In those days it was the only way I could get HD. Back then it seemed so futuristic, like everyone would be using it in 5 years time. Now, DVB-S feeds through a PC seem old hat. IPTV, on-demand, catch-up TV have all made it fairly irrelevant. I read somewhere that Sky are launching a Sky Q box that does not require any satellite feed, it does everything through IPTV. Makes me a bit sad!

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Zitat
  • DVBV can use an LNB feed if it is already correctly locked, but it can't keep hold of it, so if an outside factor changes the polarity, position, whatever it is of the LNB, DVBViewer simply loses its lock and can't get it back

This, to me, looks like an issue with DVBViewer.

What do you mean? What outside factor? The DVBV/DMS should have exclusive access to the selected hardware resources. If such an error reoccurs you should post a fresh support.zip.

 

Remember, you've connected your DVBViewer hardware to the wrong connectors of your hybrid LNB in the 1st place ;)

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7 hours ago, Derrick said:

Remember, you've connected your DVBViewer hardware to the wrong connectors of your hybrid LNB in the 1st place ;)

 

I'd just like to confirm that the Sky Q box works as intended, MediaPortal works as intended and DVBViewer does not.

 

The cables were connected to the LNB by a professional.

 

So I did not personally connect my hardware to any LNB and the person who did connect them did not connect them to the wrong LNB.

 

In fact, as I stated earlier, the best documentation I can find suggests that the LNB auto-detects the tuner type and responds accordingly, in which case it would be impossible to connect hardware to the wrong LNB connection.

 

I believe there is an issue with DVBViewer. I'd prefer to use DVBViewer if it worked, because I like it more than I like MP. But for now I'll have to use MP, because it works.

 

I believe that the LNB is identifying a DVBViewer controlled tuner as a Sky Q box, but is identifying the same tuner when controlled by MP as a conventional satellite tuner.

 

If you want to look into the issues, if you want me to test anything, I'll be happy to help and provide any information you ask for.

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On 11.11.2017 at 10:51 PM, Derrick said:

I have no idea what's going wrong but the Transedit examples could be explained by wrong IF-band selection in the LNB.

 

Looks like low/high band selection is not working reliably. It depends on the 22 kHz signal and maybe DiSEqC. The tuner outputs the 22 kHz signal continuously if a high band transponder is selected (thus telling the LNB/switch that it shall use the high band oscillator frequency), otherwise it is switched off. DiSEqC is a short modulated 22 kHz signal sent right after tuning for switching between different satellite positions. However, the Pos/Opt DiSEqC commands also contain two bits for switching between low/high and H/V. There are LNBs/switches that respond to it and even switches that won't do without it. Anyway it's something that may interfere with low/high switching.

 

"Sometimes it's working and sometimes it doesn't" suggests a timing issue. Since we don't know what the LNB expects it comes down to blind guessing / trial and error. I would try the following in TransEdit:

  • Select the transponder list, set DiSEqC  to "None" and click Apply on the left. Try to scan. Any change? If not set DiSEqC to Pos A/Opt A (-> Apply) which is the common setting if DiSEqC is not required for switching between satellite positions.
  • Close TransEdit, open the file TransEdit.ini i (see configuration folder), search the [Hardware] section and within this section the Blackgold DVB S2 tuner entries ("7231 BDA DVBS Tuner" I guess, unfortunately you've already deleted your support.zip so I don't know for sure). There are corresponding "vendor.x=6" entries for each tuner, where x is the device number. Replace 6 by 26, save and try to scan. The change lets TransEdit use a different method for sending DiSEqC commands. If it doesn't work out revert to the previous vendor value.
  • There are also corresponding "DiSEqCCount.x=1" entries for each tuner that specify how often DiSEqC commands are sent. Replace 1 by 2 or even 3 to let TransEdit send DiSEqC repeatedly. Save and try to scan.

It's important to not mix these changes up, but only try one of them at a time.

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2 hours ago, Griga said:

 

Looks like low/high band selection is not working reliably. It depends on the 22 kHz signal and maybe DiSEqC. The tuner outputs the 22 kHz signal continuously if a high band transponder is selected (thus telling the LNB/switch that it shall use the high band oscillator frequency), otherwise it is switched off. DiSEqC is a short modulated 22 kHz signal sent right after tuning for switching between different satellite positions. However, the Pos/Opt DiSEqC commands also contain two bits for switching between low/high and H/V. There are LNBs/switches that respond to it and even switches that won't do without it. Anyway it's something that may interfere with low/high switching.

 

"Sometimes it's working and sometimes it doesn't" suggests a timing issue. Since we don't know what the LNB expects it comes down to blind guessing / trial and error. I would try the following in TransEdit:

  • Select the transponder list, set DiSEqC  to "None" and click Apply on the left. Try to scan. Any change? If not set DiSEqC to Pos A/Opt A (-> Apply) which is the common setting if DiSEqC is not required for switching between satellite positions.
  • Close TransEdit, open the file TransEdit.ini i (see configuration folder), search the [Hardware] section and within this section the Blackgold DVB S2 tuner entries ("7231 BDA DVBS Tuner" I guess, unfortunately you've already deleted your support.zip so I don't know for sure). There are corresponding "vendor.x=6" entries for each tuner, where x is the device number. Replace 6 by 26, save and try to scan. The change lets TransEdit use a different method for sending DiSEqC commands. If it doesn't work out revert to the previous vendor value.
  • There are also corresponding "DiSEqCCount.x=1" entries for each tuner that specify how often DiSEqC commands are sent. Replace 1 by 2 or even 3 to let TransEdit send DiSEqC repeatedly. Save and try to scan.

It's important to not mix these changes up, but only try one of them at a time.

 

Thanks - I don't have Diseqc but will give it a go. There are 2 LNBs but they're static.

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Well the first thing I noticed - and I can't believe I didn't notice it before - was that the settings in DVBViewer for 28.2e had a diseqc position of B.

 

So I changed the settings for that satellite to 'None' and did a re-scan update so the settings for each channel are updated too.

 

I've set some recordings off and I'll report back. It can work for hours on end before failing so it'll take a while to come back to you, before I can say anything for certain. Watch this space...

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3 hours ago, uglyned said:

So I changed the settings for that satellite to 'None' and did a re-scan update so the settings for each channel are updated too.

 

It's changed automatically for all channels with the corresponding orbital position after a change on the reception settings page.

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OK so this is interesting!

 

I was wrong about MediaPortal, it just seemed like it worked, but it had the same problem. Here's why.

 

It seems to be all down to the extra LNB that's strapped onto the hybrid one.

 

If I restart the PC, all the tuning on 28.2e works fine. I can be recording a programme with no issues at all.

 

But if the LNB for 19.2e (which really is literally strapped to the hybrid one) is used, as soon as it tunes, the hybrid LNB loses its signal and the recordings start failing.

 

If I stop the use of the 19.2e LNB, the problems don't immediately go away on 28.2e The issues can remain for some time, although rebooting the PC will help.

 

However if I tune the LNB for 19.2e manually, say using a scan on Transedit, of a transponder on 19.2e that's on a similar polarity and frequency to the BBC HD one, immediately the BBC HD recording recovers.

 

So it looks like whatever it is - audio signals, whatever, that are being sent to the single LNB are being picked up by the hybrid LNB. Interestinly every one of the 4 runers on the LNB is affected, not just one. So maybe the hybrid LNB is more sensitive - it seems to be picking instructions up from the single LNB!

 

This was not the case with the old quad universal LNB and I still have it, so when I stop the Sky subscription, worst case is to just get the universal LNB bolted back on.

 

Or stop using 19.2e, just disable that tuner or unplug the cable.

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You'd better post a support.zip. It seems to me that the hardware configuration is not correct. Without switches between LNBs and tuners standard Diseqc sttings don't matter.

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Just to add a bit more detail, as I've been testing this to death!

 

I have a Sky 43cm minidish with hybrid LNB. There's an additional single LNB strapped to it. Similar to this photo.

 

https://www.flickr.com/photos/48490727@N05/6214039475/

 

The hybrid LNB receives 28.2e, the single LNB 19.2e.

 

No diseqc.

 

Start the PC. DVBViewer Recording Service works perfectly on 28.2e. Any channel, any transponder. Fine. No issues.

 

Do anything on the 19.2e LNB - scan in TransEdit, record or view a channel in DVBViewer / RS and it sends the 28.2 reception potty. Loads of discontinuities, and for prolonged periods, no signal.

 

Tune the 19.2e LNB to the same polarity and roughly the same frequency as the channel you're trying to receive on 28.2e, and 28.2e suddenly fixes itself. But only for the channel on roughly the same frequency as the 19.2e transponder.

 

Stopping any use of the 19.2e LNB, even stopping and starting the recording service, does not fix the issue.

 

Only rebooting the PC appears to reset everything to the beginning again. Doing this means I can again use 28.2e without issue. But try anything with 19.2e and the whole thing starts again.

 

As I only use 19.2e very rarely - usually for every other F1 race - I've come to the conclusion that if I set the 19.2e tuner to 'do not use' in RS, so it doesn't use it for EPG updates and throw the 28.2e LNB out, that'll be OK.

 

But if anyone has any suggestions on how I could use the two together, I'l like to read them!

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