TBSDTV Community Forum

Hi guys,

I've encountered a strange problem. I am using 1 dvb-s and 2 dvb-s2 receivers (HTPC with a TBS6920 in it and the other receiver is a Technistar Technisat S1) on my quad lnb.
Everytime my Technistar S1 is activated, my tuner card can't find some channels. I've allready switched the ports, changed the lnb, but nothing helped. Once the S1 receiver is used, my htpc is losing signals on some channels. I'm not aware of this technical stuff, but I do believe that using diffrent receivers on a quad lnb should work fine, without them having any conflicts between each other.

regards,
tikimune

Edit: All effected channels seem to use vertical polarization.

hi tikimune, it just seems on your Quad LNB outputs are affected by each others, i.e. using one of the outputs with one device affects the performance of the output connected to the other device.

cody Wrote:hi tikimune, it just seems on your Quad LNB outputs are affected by each others, i.e. using one of the outputs with one device affects the performance of the output connected to the other device.

Ok, so there's nothing I can do? Know I've tried to connect an other dvb-s2 receiver, this and the technistar s1 seem to not have any problems with each other. Only my tuner card is having issues, if one of the other receivers is activated. And like I said before, I allready switched the outputs and tested an other lnb. As far as I know, outputs on Quad LNBs should not be affected by diffrent devices. Does this mean, both of my lnbs are broken?

Hmm I'm not quite sure, but maybe my TBS6920 just can't handle the 22kHz modulation signal?

tikimune Wrote:Hmm I'm not quite sure, but maybe my TBS6920 just can't handle the 22kHz modulation signal?

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if there is hardware issue with 22kHz tone circuit on your TBS 6920 then you won't be able to receive transponders over 11700 MHz. in any case if you wish you can send back your TBS 6920 card to us for diagnostics and we will replace it with new one in case there is indeed hardware fault. maybe, i didn't understand very well description of your problem and it's some hardware fault of your TBS 6920 card.

cody Wrote:maybe, i didn't understand very well description of your problem and it's some hardware fault of your TBS 6920 card.

Ok, then let me try again.

I am using 3 types of DVB-S receivers. One old-fashoined DVB-S receiver, one DVB-S2 receiver (Technisat S1) and a htpc with a TBS6920 TV card in it. All receivers are connected to a Quad LNB.
As long as the htpc is the only receiver that is used, all works fine. But soon as I turn on another receiver, all vertical channels on my htpc are gone. No matter one or both receivers are used, everytime I'm losing my channels.
The other receivers are not affected. Means. if the DVB-S receiver is on, you can turn on the Technisat S1 and watch TV without limitations.
So I started some troubleshooting, exchanged the ports on my LNB but the problem still appears. I even changed the LNB, but no change. The 22khz thing was just a guess, now I know that 22khz is not only used for vertical but also for some horizontal channels.

tikimune Wrote:... now I know that 22khz is not only used for vertical but also for some horizontal channels.

i definitely get better understanding of your setup. let me explain how the (Universal) LNB is controlled:

* 13V (or a little over) supplied by the receiver means "Vertical"
* 18V (or a little over) supplied by the receiver means "Horizontal"
* 22 kHz off (22 kHz are not sent by the receiver) means LNB Local Oscillator Frequency (LOF) is set to 9750 MHz
* 22 kHz on (22kHz are sent by the receiver) means LNB Local Oscillator Frequency (LOF) is set to 10600 MHz

so, based on the above on you problem description it seems your quad LNB starts to ignore power supply for "Vertical" sends by your 6920 card, when the other receivers are in use. i think it couldn't be hardware fault of your 6920 card, because otherwise you won't have vertical at all (if the LNB power circuit is broken) under any circumstances. so, it really sounds like incompatibility problem between the LNB and the 6920. in any case as i mentioned there is no problem to replace your 6920 board, but i believe the same will happen, because it's for some reason your quad LNB doesn't like the power supply for "Vertical" that is sent by 6920 when the other receivers are in use. i agree it's really strange, because at least i expect the quad LNB has 4 completely independent LNBs inside, which doesn't seem to be true with your quad LNB. actually, maybe, your quad LNB manufacturer will have better idea about the problem, because they know how their LNB is working internally.

Ok, finally I've tested a Technisat UNYSAT Quatro-Switch-LNB. Which is one of the best LNBs on the market, regarding to some consumer magazines. The issue still appears. I have no doubt, that there's something wrong with my card. Thanks for your help so far cody.

tikimune Wrote:Ok, finally I've tested a Technisat UNYSAT Quatro-Switch-LNB. Which is one of the best LNBs on the market, regarding to some consumer magazines.

you know that Technisat paid to those magazines to say that, right?

tikimune Wrote:The issue still appears. I have no doubt, that there's something wrong with my card. Thanks for your help so far cody.

i offered you from the very beginning to exchange the card for you, but i personally have doubts that the issue is the card and that will resolve the issue.

Hey cody,

I just wanted you to know that my seller sent me a TBS6921 as a replacement for my TBS6920. I've tested this new card with my quad LNB and my problems vanished. But now I don't know whether it was only a problem with my TBS6920 or all of them.

Thanks for your help again.