CBS DVB-S2 feeds 99w Ku

[nc-jay]

CBS recently switched to DVB-S2, 4000SR, and 1080i for most of their 99w Ku feeds. I notice that my December software X2 Premium struggles with these feeds - it appears to it that the signal is weak, and the video regularly breaks up in a way that makes it appear blocky-pixely.

This is a real surprise, since I haven't found any ITC 4:2:0 video that the X2 can't handle, and especially surprising since the Vantage 1100S handles the CBS feeds with ease - but struggles on other signals. A friend with the same receivers is noticing the same thing.

Is this something we can get looked at, please?

Thanks
nc-jay

[jkara]

Also observed video pixellation on same channels with APR. 2013 FW.

I'm using 8' CM SMC dish w/orthomode feed and NJR LNBs.

jkara - NY

[Costactc]

Any specific tp?

[jkara]

Any specific tp?

Most Ku CBS S2 Vertical TPs that are HD and SR 4000. Compare these with CBS Newspath DVB-S and you'll see.

When you add up their bad weather, a non-commercial receive dish and S2 on Ku = possible errors..

Still having fun with this STB despite some bugs!

[Costactc]

I'll have a look and report back.

[Costactc]

Of all of the hd CBS feeds and there are quite a few on G16, only was glitchy but with strong signal quality on my 4' dish:

11806 V 4000

[el bandido]

CBS recently switched to DVB-S2, 4000SR, and 1080i for most of their 99w Ku feeds. I notice that my December software X2 Premium struggles with these feeds - it appears to it that the signal is weak, and the video regularly breaks up in a way that makes it appear blocky-pixely.

This is a real surprise, since I haven't found any ITC 4:2:0 video that the X2 can't handle, and especially surprising since the Vantage 1100S handles the CBS feeds with ease - but struggles on other signals. A friend with the same receivers is noticing the same thing.

Is this something we can get looked at, please?

Thanks
nc-jay

How did you test the Vantage against the X2? Did you watch the X2 until it started breaking up and then immediately replace it with the Vantage using the exact same antenna cable?

[nc-jay]

How did you test the Vantage against the X2? Did you watch the X2 until it started breaking up and then immediately replace it with the Vantage using the exact same antenna cable?

A valid question. The signals on the X2 were breaking up from tunein, no waiting involved. But first a note about the (satellite) RF topology here.

Eight dishes in the yard, each with its own LNB, are cabled into an array of 4x8 multiswitches, and from those to eight DiSEqC switches, each of seven feeding one receiver, each with its own dedicated monitor. (The eighth is on a Prof 7500 attached to a Windows box.) So I can use the same dish/LNB combo - in this case, the dish is a steerable Prodelin 1.8m offset - and watch on as many receiver/monitor combos as I choose. In my report at the top of the thread, I was comparing reception on the same signals simultaneously as received by the X2 and the Vantage.

Unfortunately - or perhaps fortunately - I was unable to reproduce the video breakup today on any of the six CBS S2 HD feeds present at the moment - 11775, 11780, 11791, 11804, 11820, and 11836 (all Vertical and 4000 SR). So for the time being I guess we can consider this one less of a priority. If I see something different at another time, I'll follow up here.

jkara, what are you seeing?

nc-jay

[Costactc]

A valid question. The signals on the X2 were breaking up from tunein, no waiting involved. But first a note about the (satellite) RF topology here.

Eight dishes in the yard, each with its own LNB, are cabled into an array of 4x8 multiswitches, and from those to eight DiSEqC switches, each of seven feeding one receiver, each with its own dedicated monitor. (The eighth is on a Prof 7500 attached to a Windows box.) So I can use the same dish/LNB combo - in this case, the dish is a steerable Prodelin 1.8m offset - and watch on as many receiver/monitor combos as I choose. In my report at the top of the thread, I was comparing reception on the same signals simultaneously as received by the X2 and the Vantage.

Unfortunately - or perhaps fortunately - I was unable to reproduce the video breakup today on any of the six CBS S2 HD feeds present at the moment - 11775, 11780, 11791, 11804, 11820, and 11836 (all Vertical and 4000 SR). So for the time being I guess we can consider this one less of a priority. If I see something different at another time, I'll follow up here.

jkara, what are you seeing?

nc-jay

I'll start by saying that sounds like a real nice setup you have. Cbs feeds are still a bit glitchy for me today.

[el bandido]

A valid question. The signals on the X2 were breaking up from tunein, no waiting involved. But first a note about the (satellite) RF topology here.

Eight dishes in the yard, each with its own LNB, are cabled into an array of 4x8 multiswitches, and from those to eight DiSEqC switches, each of seven feeding one receiver, each with its own dedicated monitor. (The eighth is on a Prof 7500 attached to a Windows box.) So I can use the same dish/LNB combo - in this case, the dish is a steerable Prodelin 1.8m offset - and watch on as many receiver/monitor combos as I choose. In my report at the top of the thread, I was comparing reception on the same signals simultaneously as received by the X2 and the Vantage.

Unfortunately - or perhaps fortunately - I was unable to reproduce the video breakup today on any of the six CBS S2 HD feeds present at the moment - 11775, 11780, 11791, 11804, 11820, and 11836 (all Vertical and 4000 SR). So for the time being I guess we can consider this one less of a priority. If I see something different at another time, I'll follow up here.

jkara, what are you seeing?

nc-jay

This is a nice system you have but it has too many variables to condemn the X2 and say that it is the reason you are having problems with the 4000sr Ku CBS feeds at 99W. You will need to swap receivers and use the exact same cabling when the problem occurs again, or you may trade places now, putting the X2 where the Vantage is, and move the Vantage to where the X2 is. Doing this would allow you to see if the problem follows the X2. Doing this might narrow it down a bit.

Moisture can be a problem in connectors this time of year and your antenna system has a bunch of connectors in it. A bad cable somewhere could do the same thing. The problem you have described seems to be a moisture or cable type problem. It is also possible that your C/Ku lnb combo may not be illuminating the whole dish.

I find the CBS feeds on 99W to be not as strong as most other transponders on that satellite. It would not take a lot of signal attenuation before I would see pixelation or breakup on these CBS feeds using a 1.8 meter Ku dish.

C/Ku Lnb combinations are almost always some form of a compromise that results in one or both bands losing signal as compared to a single C or Ku lnb being optimized on the same dish. It is pretty common for the Ku lnb of a C/Ku combination to only illuminate about 1 meter of the dish, regardless of the dish size. EB

[nc-jay]

Well, I didn't really condemn the X2. I really like the receiver, and have added a second one into the mix here.

A couple of points of information, since you bring them up: agreed regarding moisture, however the only thing in the entire mix that's outside is the dish and LNB. The multiswitches, diseqcs etc are all indoors and well protected from moisture.

Also, C/Ku LNB combinations are not an issue here. The dishes are either dedicated C or Ku.

nc-jay

[el bandido]

OK.
It looks like the other person might have a C/Ku. You have individual dishes then you should be getting at least the signal I get in NC if not more. I think trading the X2 and the Vantage will probably give you the most information on this problem.

The X2 receiver or its firmware could be the issue, but everything seems OK here using the December firmware. I have not updated my X2 lately.

Another thing you might test is slowly moving the dish off some signals and see which receiver breaks up and loses the signal first. Then swap the receivers, repeat the test exactly as the first time and see if the results are the same.

[jkara]

Jay, Costactc and el bandido,

The second day of testing was better. 50% of the TPs you mentioned came in clear with X2 and solid although they seem lower in power (as viewed on a spectrum analyzer) since the shift to S2.

I believe my issue was the extreme weather they were having (I broomed off my dish again!). The Vantage did struggle with a couple of them but was only intermittent then stablized. It's no wonder I had some glitches with the extreme N.E. weather. We'll see how this all pans out when the skies clear up..

I use a 4-way splitter from my main powered receiver to connect 3 addtional STBs inside. Not as elaborate as your setup. Also C/Ku Seavey ortho on 8'CM
SMC does Ku well but I suspect the 1.8 Prod would blow it away on Ku.

[el bandido]

Usually a firmware issue will be consistent and not change with the weather. For the Ku band, I am running multiple receivers(4) from one quad LNB. One thing I have noticed in my system is some LNB cable feeds will show a bit better connection than others. It is common for my receiver to vary by around 1db when connected to different ports of the quad LNB. This is why I mentioned trading places with the receivers to see if the problem follows the receiver.

Also try moving the dish a small amount and see which receiver breaks up or loses signal first. It may be that the Vantage has a better tuner than the X2 and is more able to cope with a minimal signal than the X2. EB

[el bandido]

I have spent some time over the past few days looking at these CBS feeds. I noticed some of them were breaking up-even when I had an acceptable signal. These feeds were tested with different receivers using the exact same coax feed. Some of the break up problem seems to be on the CBS end.

Various charts that are published show that I can expect to lose these CBS feeds if my CNR falls below 7.9db. The calculated CNR values are real close to what my receiver actually needs to open these channels.
In good conditions, I might get 13.0db SNR on these CBS transponders using a 1.8 meter dish. This dish is dedicated to the KU band and it has an Inverto quad lnb connected to an Invacom ADF120 adjustable feed horn.
In Inclement weather, I might have 11 or 12 SNR for these CBS feeds, and I can expect to lose them all together with a decent rain.
The X2 does not seem to break up any more or less than the other receiver that I compared it to on these feeds. EB


Below are given the minimal carrier-to-noise ratio values required to lock the signal broadcast in DVB-S2 standard
DVB-S2 8PSK:
FEC SNR
3/5 5.5
2/3 6.6
3/4 7.9
5/6 9.4
8/9 10.6
9/10 11

7104 7105

[rrob311]

eb is there a way to look up the snr or cnr on a regular receiver or is something more advanced or a pc required? Is that an e2 firmware of some sort that you are taking that reading with?

[el bandido]

Yes. That is E2. Most fta receivers do not provide a SNR in db option. And not all e2 images have the SNR in db option either, but most of the ones I have tried do have SNR in db.