MT PBS switch to S2

[Blindowl1234]

LPB is lower but stays in until a few hours after dark though. Montana PBS must have something weird going on there. It acts like something is covering the lnb for a second...best way to describe it. No problem on any other channel. Not exactly watchable...Blind

 

[Sadie]

Now I have the bigger dish Montana is fairly solid for me but like other people have been saying occasionally it will drop right out for a few hours then suddenly come back on really strong again. The must be a rational reason for these but I can't figure it out, possible weak signal subject to co channel interference from other sources? or do they use different uplink facilities at different times?

LPS is also another odd signal its usually strong but I need a Q of over 80 to get a good picture, Montana and OETA are good down to a Q of 15!

 

[stogie5150]

LPB is lower but stays in until a few hours after dark though. Montana PBS must have something weird going on there. It acts like something is covering the lnb for a second...best way to describe it. No problem on any other channel. Not exactly watchable...Blind

My 1m/Sathawk combo does the same thing. It does it on most DVB-S2 Ku signals though, with the notable exception of the NBC's. Has to be something about the signal.

 

[Keith Brannen]

LPB is lower but stays in until a few hours after dark though. Montana PBS must have something weird going on there. It acts like something is covering the lnb for a second...best way to describe it. No problem on any other channel. Not exactly watchable...Blind

That is a very good way to describe what I am also experiencing with Montana PBS. Now, I have only had my AZBox for a week, but tonight was the first night that I experienced pixelation and dropout of LPB, and then it was only for a while. It is fine now.

What makes me laugh (and is typical) is that the changeover to S2 of Montana PBS is the reason I finally got an AZBox! I am certainly not complaining, considering all that I am getting now, it just seems ironic that Montana PBS is the one channel that is unwatchable most of the time.

 

[Blindowl1234]

All my other S2 stuff is very watchable except for the stuttering on some channels. But the Montana PBS seems to be a totally different problem. It goes from a great picture to zilch then back to a great picture, all in a matter of seconds. I guess I could try and see what happens if I hook up the Ku portion of my Geosat lnb on the 8 foot dish. Blind

 

[woodheat/nooil]

Would a "Phase Lock Loop" lnb help if the signal drifts back and forth?

 

[woodheat/nooil]

I just got this email when I asked about a PLL lnb would help get PBSMT.
I am not a registered user on the forums but I have begun lurking a bit but not every day by any means.

The switch to S2 has been smooth for all the downlink sites I have in Montana (55+). I have always based our path predictions on a dish no less than 1.8 M. I know a lot of the FTA folks use smaller ( I have a hobbyist in Denver that uses a 95cm dish and the 9865 ird with a 1.3 db margin).The predicted path budget for the S2 signal came in right on the money in real life and is within .5db of the old DVB-S signal. I did settle on the Cisco 9865 for the IRD to deploy at my downlinks following a great deal of testing. I did not even try some of the low end units. I use a Tandberg encoder/modulator and it is MPEG4 encoding. Pilot is “on”.
I did not change a single LNB at any of these sites. Maybe over time we will see a need… but haven’t yet.

One bit of unfortunate coincidence however! This past weekend we experienced an intermittent power control issue at the on the uplink. The signal was up and down several times. I believe it was solved Monday morning and the signal strength has remained constant from that time.
This switch has reduced the transponder costs tremendously and enabled us to stay on the satellite. The FTA community is very creative and resourceful. I think it would be critical to identify a reliable and helpful dealer that can assist in IRD selection. There will be a lot more S2 soon. The economics will drive this.

BTW, we keep this feed “in the clear” for the FTA folks.
Please feel free to post this note.



Best regards,
Dean Lawver
Director of technology
MontanaPBS

 

[LoTech]

I was flipping through the 125W channels a few nights ago, and every time I would switch to MT PBS I had the same problem. The picture would flash on for a couple seconds, and then the TV would go dark and the receiver (CS 8000HD) would shut down and reset. When it came back up I would have to change the channel before the signal lock or it would shut down again. This has never happened on any other channel or signal type. Even though the signal quality was maxing the meter, I thought about removing MT PBS from the channel list. Glad I didn't, because after about 24 hours the problem went away.

 

[toucan-man]

BTW, we keep this feed “in the clear” for the FTA folks.

Thanks, Dean.

 

[Sadie]

Its great to get that kind of feedback from the station, he makes a valuable point about S2

There will be a lot more S2 soon. The economics will drive this.

The "issue" they had with the uplink over the weekend explained the "issue" I had, I just hope a similar loss I had this morning can be explained in the same way.

I'm a little bit skeptical that the signal is within 0.5dB of the old signal, its possible, I haven't been able to receive it for long but I had to go from a 1 meter dish to a 1.2 meter dish an increase in gain of about 1.3dB, the quality is about the same but the range in quality that produces a good picture is increased so maybe he is right and its a characteristic of my receiver.

I found this useful guide to DVB S2 which has some interesting tables starting on page 11 showing the Carrier/Noise ratio for threshold for different DVB and DVB S2 signals for different modulation types and FEC values

 

[TRG]

That was a nice reply from Dean. He seems very FTA friendly. Now if I can just talk my wife into a 1.8 m Ku setup to watch Montana PBS I'd be in business.

None of this explains the weaker signal however. They say that the new S2 signal is within .5 dB of the old DVB-S signal. I'm no expert but from my sofa I'd say thats impossible. I bought my sathawk specifically so I could my favorite programing on MPBS Saturday nights. Last Saturday the signal was barely there. Earlier in the week my signal Q was in the high 70's low 80's like the other HD mux's on 125W. I don't think we got the whole story.

Could it be that there is interference from an adjacent satellite?

 

[1inabillion]

Very strange. i never had any issues with Montana PBS before or after the switch to S-2 Am or Pm

nor do i have issues with any S-2 feeds in my Los out side of weather with my current setups. must be my 20

 

[B.J.]

....

nor do i have issues with any S-2 feeds in my Los out side of weather with my current setups. .....

What about the 5 or 6 S2 transponders on AMC21 that have 30000 SR?
Of those 5 or 6 transponders, one comes in real strong, one comes in occasionally , but weak, and I don't get a hint on the other ones.
I really get the impression that some of the footprints on the AMC21 transponders are a bit irregular. I know that AMC21 has both a CONUS and Carribbean capability, and on some lists I've seen some of these transponders attributed to the other beams, but maybe it's just that the beams are adjustable, and they aren't all the same? Just a guess.
But I don't generally have problems with Montanna either, with my 90CM, however I seldom watch programs on it. I just occasionally tune it in to make sure that I can.

 

[Sadie]

What kind of signal folks are getting depends a lot on where they are in AMC 21 footprint those out of the center of the beam have the toughest time. It seems if you didn't have much of a margin with the original DVB signal you need to go up one dish size to get the new S2 signal with about the same margin.

That said the does seem to be some kind of interference issue I notice that at some times bumping the dish makes no difference but right now bumping it 1/2 degree to the west brings the Q up 20 points, I doubt if the stations with their 1.8M dishes and narrow beam width would notice this.

 

[Keith Brannen]

That said the does seem to be some kind of interference issue I notice that at some times bumping the dish makes no difference but right now bumping it 1/2 degree to the west brings the Q up 20 points, I doubt if the stations with their 1.8M dishes and narrow beam width would notice this.

According to Lyngsat (I don't have a dish on 123 anymore so can't confirm) UWTV recently went DVB-S2 (12104 V 3361), possibly could be interferring (I know it did when they were both DVB-S as I had to re-point both dishes slightly away from the other satellite). Agrees with your increase by bumping 125 to the west.

 

[Sadie]

According to Lyngsat (I don't have a dish on 123 anymore so can't confirm) UWTV recently went DVB-S2 (12104 V 3361), possibly could be interferring (I know it did when they were both DVB-S as I had to re-point both dishes slightly away from the other satellite). Agrees with your increase by bumping 125 to the west.

Great observation! I just checked and UWTV is booming in on 123W at 12104 V 3361. I thought engineers where supposed to avoid this kind of thing, two signals on adjacent satellites only 2MHZ apart and using the same polarization.

Those of us that have motors have the option of bumping the dish over to the west, its going to hard on those folks with fixed mounts that need the best signal on Montana, not sure what other options are available.

 

[LoTech]

The problem I mentioned earlier is back. This morning I turned on MT PBS and bang... my CS8000 rebooted. Just to double check I tried every other channel in my channel list (DVB-S and DVB-S2), and they worked just fine (including the ones on 85W). So, I decide to check MT PBS again, and just like before I get a reboot. Is there something different or unique about the signal on this specific channel that might cause this problem? Also, is anyone else having this problem?

 

[updatelee]

Cc is broadcast via line 21 of the actual video. It isn't sent over hdmi either. So the receiver would have to decode the line21 video then use it's own internal osd to display the cc. This is how dreambox does it. Most don't and send them over the video as per spec.

 

[TRG]

The problem I mentioned earlier is back. This morning I turned on MT PBS and bang... my CS8000 rebooted. Just to double check I tried every other channel in my channel list (DVB-S and DVB-S2), and they worked just fine (including the ones on 85W). So, I decide to check MT PBS again, and just like before I get a reboot. Is there something different or unique about the signal on this specific channel that might cause this problem? Also, is anyone else having this problem?

I don't have a CS8000 but I've noticed that the signal is lower than before. I don't know if low S2 signal levels have anything to do with your issue but I thought I'd mention it.

 

[Blindowl1234]

Well I checked today and it's still dropping out on me. No other issues with any other channels S2 or otherwise on any bird. I'm using the Sathawk and a 36" Primestar dish...Guess I'll learn to live without MT PBS...Blind