4 LNB / Astra 28.2 / 2 PCs / 2 DVB-S cards - configuration help sought

[Alan Hazell]

Hi,

 

I wouldn't consider myself a newbie as I have been using DVBViewer for some time but I am getting very frustrated trying to get my hardware working correctly now that I have had two additional cables connected to my existing dish that I had upgraded from a 2 way LNB to a 4 way LNB.

 

This is what I have....

 

2 Windows 7 PCs, each with 1 Blackgold BGT3540 dual DVB-S/DVB-T card

2 installations of DVBViewer v4.2.1.0, with 1 running on each PC.

Currently each instance of DVBViewer is running with the same settings, aside from variations due to save location etc.

 

I would like to know how to get each instance of DVBViewer to correctly switch the LNBs as since I have started using the two new cables I am getting tuning conflicts on both PCs and there seems to be no obvious cause.

 

For example, at present I am recording BBC HD and BBC 2 Scotland on this PC. And BBC2 Scotland on the other. I am currently unable to tune to ITV1 HD on the fourth and free tuner on the other PC. Each tuner has a dedicated cable and LNB so I do not believe I need to enable the Shared LNB option in the Hardware settings tab.

 

I have previously discovered through trial-and-error that I need 'Stop stream while tuning' set for these cards to get consecutive recordings from different frequencies to tune correctly. Otherwise no data is saved.

 

I have a attached a screenshot of the Hardware tab. One DVB-S tuner is set to Preferred and the other to Normal. (The Hauppauge freeview card exists in one machine only and is not relevant)

 

 

It should be noted that independently each PC tunes to and records fine from both DVB-S tuners but it is only when I have them and the two instances of DVBViewer running simultaneously that I am having problems. I am confident that I do not have any signal issues and the installer tested each cable and I was witness to his meter tests.

 

Firstly, for my setup described above, do I need the power connection made to both cards at the same time?

Secondly, do I need to use any DiSeqC settings and rescan the channels on both PCs, now that I have two separate cards making individual tuning requests of my 4 LNBs?

 

Regards,

 

Alan

 

support.zip

Edited June 2, 2011 by Alan Hazell

[Griga]

For example, at present I am recording BBC HD and BBC 2 Scotland on this PC. And BBC2 Scotland on the other. I am currently unable to tune to ITV1 HD on the fourth and free tuner on the other PC.

 

BBC 2 Scotland: 10802 H

ITV HD: 10935 V

 

which means, the tuners are supplying the LNB with a different voltage (usually H = 18 V, V = 14 V). Please check if the issue is generally caused by a H/V difference between two channels.

 

Potential differences between the electrical grounding are a common issue with 2/4-way LNBs, particularly when a receiver and a DVB card or two DVB cards are connected to such a LNB. Potential differences may pull the voltage delivered by one or the other card up/down, so that H/V switching doesn't work properly anymore.

[Alan Hazell]

I didn't realise how out of date v4.2.1.0 is - so I will upgrade to the latest version tonight when I get home from work and report back.

 

Apologies for my frustrated tone above. When it works fine it works great but when it doesn't it can be a real pain. I find if something isn't right with the software configuration, and I get discontinuities or failed recordings, I'll get it sorted and then a few weeks later I'll have a hardware issue, such as a PSU dying one me, as it did last week :'(

 

I want to get everything running in a stable and reliable state before the UK music festival coverage starts i.e. Glastonbury at the end of June.

 

Can anyone recommend a good primer on satellite control so that I can read up? My dish is fixed to 28.2 degs and I don't plan to change this, but I would really like to understand how my LNBs work, and how DVBViewer controls them.

[Griga]

4 way LNB = 4 LNBs in a single casing, that are sharing the same grounding. The electrical grounding should be neutral, but sometimes it isn't in practice, which means there may be a voltage (potential) difference between the grounding of two receivers / DVB cards connected to such a LNB, causing unwanted electrical interferences.

 

As already written above : Switching between horizontal (H) and vertical (V) polarization depends on the voltage delivered by receivers/cards, which may be influenced by such a potential difference. So you should check if H/V is related to the problem, e.g. all H channels work in a given situation, all V channels don't.

[Alan Hazell]

BBC 2 Scotland: 10802 H

ITV HD: 10935 V

 

which means, the tuners are supplying the LNB with a different voltage (usually H = 18 V, V = 14 V). Please check if the issue is generally caused by a H/V difference between two channels.

 

Potential differences between the electrical grounding are a common issue with 2/4-way LNBs, particularly when a receiver and a DVB card or two DVB cards are connected to such a LNB. Potential differences may pull the voltage delivered by one or the other card up/down, so that H/V switching doesn't work properly anymore.

 

Thanks for the response.

 

***************

 

I have just picked up your second reply also.

 

I will try tuning to 4 H channels tonight, and subsequently 4 V channels. Therefore, if there is a grounding issue we could expect that one or more tuners will fail to obtain a signal in one or other scenario.

 

Will the setting "Disable LNB on device releasing" have any bearing on the issue, once I upgrade DVBViewer? Presumably this releasing is not happening at the moment with v4.2.1.0

[Griga]

Will the setting "Disable LNB on device releasing" have any bearing on the issue, once I upgrade DVBViewer?

No. Blackgold devices/drives don't support LNB voltage control by the DVB application.

[Griga]

I will try tuning to 4 H channels tonight, and subsequently 4 V channels.

I would do it in the following way:

 

- Let the tuners in PC #1 receive a H and a V channel simultaneously, e.g. by watching BBC 2 Scotland (H) and recording BBC HD (V), as described in your first post.

 

- While the tuners in PC #1 are busy, check which channels on PC #2 are affected and whether they belong to the H or V category.

[Alan Hazell]

I would do it in the following way:

 

- Let the tuners in PC #1 receive a H and a V channel simultaneously, e.g. by watching BBC 2 Scotland (H) and recording BBC HD (V), as described in your first post.

 

- While the tuners in PC #1 are busy, check which channels on PC #2 are affected and whether they belong to the H or V category.

 

Will do.

 

From what my installation engineer has just told me, I have a Skyware quad-LNB fitted to a Sky mini dish. He can't remember the model but he believes the LNB to be of the "older" type.

 

According to the following link, http://www.satcure.com/tech/lnb.htm , the voltages are as follows...

 

"Polarisation switching is controlled by dc voltage supplied by the receiver. 12.5v to 14.5v gives vertical and 15.0 to 18v gives horizontal polarisation."

 

There are some pictures here so I might be able to identify my LNB when I get home, http://www.satcure.com/tech/LNBpics.htm

[Alan Hazell]

I would do it in the following way:

 

- Let the tuners in PC #1 receive a H and a V channel simultaneously, e.g. by watching BBC 2 Scotland (H) and recording BBC HD (V), as described in your first post.

 

- While the tuners in PC #1 are busy, check which channels on PC #2 are affected and whether they belong to the H or V category.

 

Right, here we go...

 

Firstly, I'm still running v4.2.1.0.

 

PC #2 now has the latest 0282 transponder list and a full scan completed 10714-12643, and it looks complete.

 

PC #1 = recording BBC2 Scotland 10803 H, viewing BBC HD 10847 V

 

PC #2 = recording BBC2 Scotland 10803 H on Tuner 1 (Preferred)...

Tuner 2...

10714 H N/A

10729 V Available, but discontinuities ~50 in a minute

10744 H N/A

10758 V Available, but discontinuities ~50 in a minute

10773 H N/A

.....

10818 V Available, but discontinuities ~50 in a minute

10832 H N/A ......and so on.

4365 discontinuities in recording (H) and in DVB Source while viewing (V)

 

PC #2 = recording BBC 1 W Mids 10788 V on Tuner 1...

Tuner 2...

10714 H N/A

10729 V Available, but discontinuities ~50 in a minute

10744 H N/A

10758 V Available, but discontinuities ~50 in a minute

Close graph

1000+ discontinuities in recording.

View BBC1 W Mids 10788 V on Tuner 1...still discontinuities

 

(While all this was going on..)

 

PC #1 = recording BBC2 Scotland 10803 H = 2.67Gb, 0 discontinuities

PC #1 Tuner 2 viewing BBC HD 10847 V, 0 discontinuities displayed in DVB Source

 

while still seeing discontinuities on PC #2

 

Definitely something isn't right and possibly what you described.

[Griga]

That's what I call a systematic test. Now, in order to pinpoint the source of the trouble further...

 

PC #2 = recording BBC2 Scotland 10803 H on Tuner 1 (Preferred)...

Tuner 2...

Same results with PC #2 Tuner 1 inactive?

 

If yes, same results with PC #1 not viewing BBC HD 10847 V?

 

If yes, same results with PC #1 not recording BBC2 Scotland 10803 H?

 

...or with other words, under which circumstances does it work as expected?

[Alan Hazell]

That's what I call a systematic test. Now, in order to pinpoint the source of the trouble further...

 

 

Same results with PC #2 Tuner 1 inactive?

 

If yes, same results with PC #1 not viewing BBC HD 10847 V?

 

If yes, same results with PC #1 not recording BBC2 Scotland 10803 H?

 

...or with other words, under which circumstances does it work as expected?

 

A lot to update you on now.

I suspected the floppy disk connector to the card in PC #2 was suspect, as is the power supply itself. So I've just relocated the Blackgold card into a Dell Vostro 200. This meant having to change the bracket to the low profile one and the same with the graphics to get HDMI into the telly where the cables are....

Anyway, this confirmed the fault is still there. This is the same DVBViewer config. And I copied the latest channels across. ;-)

However, on turning off PC #1 and PC #2, and then using PC #2 only I still have the problem.

 

PC #2 recording BBC 2 Scotland 10803 H on Tuner 1 (Preferred) (Same cable as before, I marked one of them with tape)

Tuner 2...

As before. Can only tune to a V, and H's not available.

However, no discontinuities that I can see! Presumably due to PC #1 being turned off

 

PC #2 = recording BBC 1 W Mids 10788 V on Tuner 1

Tuner 2...

Can only tune to a V, and H's not available.

No discontinuities.

Swapped cables and repeated with BBC 1 W Mids. H's STILL not available to Tuner 2.

Swapped cables back.

Changed tuner priority.

Tuner 1 (was/is really tuner 2!)...V's available, no H's

Tuner 2...V's available, and H's

 

Therefore, I believe the tuner detected/enumerated as 7162 BDA DVBS Tuner (3) is not capable of connecting to a channel with Horizontal polarisation. This is the outermost connection on the card i.e. furthest from the PCI-E slot.

 

It remains therefore for me to test one thing. Do I still get discontinuities on PC #2 if I do not use this "bad" tuner and put PC #1 back on...NO! :-) Seems stable. Swapped cables, still fine.

 

Cue awkward moment of realisation and disappointment... I bought the Blackgold BGT3540 card in PC #2 off eBay last year and have not used it properly until I had the additional cables installed last month. Ergo - card is ******!!

 

The all important question: is it the lack of the appropriate 18V being supplied to the LNB via 7162 BDA DVBS Tuner (3) or the tuner itself? And is there anything I can do to fix it?

Edited June 3, 2011 by Alan Hazell

[amontillado]

Btw.. a bit offtopic but maybe relevant for your testing. BBC is switching to DVB-S2 for the HD transponders (also see link). If I'm not mistaken your card is only DVB-S so if you do any testing after 6th of june you better don't use the bbc hd transponder.

[Alan Hazell]

Btw.. a bit offtopic but maybe relevant for your testing. BBC is switching to DVB-S2 for the HD transponders (also see link). If I'm not mistaken your card is only DVB-S so if you do any testing after 6th of june you better don't use the bbc hd transponder.

 

Your post could not be more appropriate. So thanks. I was thinking of upgrading the cards anyway due to them not having the more secure threaded F-type connectors. The migration of these channels to DVB-S2 clinches it.

 

Alan