? transponders missing on 77 DBS

[B.J.]

I was just surfing through the 77W DBS sat, looking for anything new, and I noticed that I couldn't lock 3 or 4 (perhaps more) of the transponders that I used to be able to lock. They weren't transponders with anything of interest on them, but I'm just curious what's going on. I did a spectrum scan, and the transponders are still there signal wise, but I can't lock them. I thought that maybe they switched to 8PSK, so I tried them on my Genpix, but couldn't lock them with that either.

Anyway, the signals that I can't lock are just as strong as the ones that I lock easily, so it's strange. One of the transponders that I can't lock is 12399R, in case anyone wants to try. It does seem to be wider than the other transponders, but I've tried all the common SR values with both QPSK and 8PSK, and can't lock it.
I also tried in DSS mode, and still no luck.

Anyway, I'd be interested in whether anyone else can lock 12399R on this sat. I guess in the meantime, I'll hook up the SW radio and make sure that they haven't switched to an unusual SR value, but from the width of the signal, it looks like 21500.


EDIT: Just used SW method, and the SR is 22500. But I still can't lock via any mode I can do.

 

[photoman76]

They are QPSK Turbo with FEC 5/6. I can lock them, but TSReader seems to hang and gives no data.

 

[B.J.]

They are QPSK Turbo with FEC 5/6. I can lock them, but TSReader seems to hang and gives no data.

Thanks. I had tried the turbo QPSK. Unfortunately, my Genpix only gives me options for 1/4 , 1/2 , and 3/4 FEC on the turbo QPSK mode. ??? I wonder if it's a limitation of the tuner in the Genpix, or just the driver. I understand that there are some differences between the Skywalker-1 I'm using and the older version that uses the DN tuner. Perhaps this tuner doesn't do all the FEC values.

What receiver/ version were you using?

 

[photoman76]

I'm using the DVBTech usb adapter. I don't have 5/6 FEC either. But it locks with 1/4, 1/2, and 3/4.

 

[B.J.]

I'm using the DVBTech usb adapter. I don't have 5/6 FEC either. But it locks with 1/4, 1/2, and 3/4.

Thanks. Can't get it to lock on any of the 3 FEC values. Oh well.

While on the topic though, I'm trying to mentally rationalize what 1/4 FEC implies. It seems to imply that the entire stream must be sent 4 times or something to that effect, ie 3 times as much error correction as actual content.

 

[Mr Tony]

on 11/4 2 TP"s changed....changed so they could load some HD locals on there (and they needed more room than what a QPSK 20000 s/r has)

EchoStar8 77W TP 13 ConUS beam changed from 20000 QPSK 5/6 to 22500 QPSK TURBO CODED 5/6
EchoStar8 77W TP 32 ConUS beam changed from 20000 QPSK 5/6 to 22500 QPSK TURBO CODED 5/6

 

[B.J.]

It seems like every time I go to check out 77 that more transponders won't lock. As above, they are still there, and quite strong, but have switched SR and apparently are in the turbo mode. In fact now, it looks like I'm only able to lock something like 4 of the 16 transponders.
Apparently, both the Genpix and TSREADER have a problem with that 5/6 FEC, so I'm keeping an eye out for new versions of both software.

That 77 sat is using an interesting configuration of transponders. They are apparently in a 16 transponder mode, which seemed unusual, but I guess they are able to put out more power into those transponders, plus they are able to avoid interferrence with the Mexican transponders on Echo-4.

Whenever I do a spectrum scan of 77, both the R and L polarities look to be perfectly symmetrical with a lot of space between the 8 peaks, and I had assumed that the other polarity was midway between the peaks of the other polarity, but on closer look, that isn't the case, apparently because the polarities and freqs of the original transponders are pretty much cast in stone. Instead, Echo-8 is using transponders 1,4,5,8,9, 12,13, etc, etc, so that each pair is close together and far from the previous pair, and Echo-4 is using the in between space.

I've made a little chart of the Echo-8 and Echo-4 transponders. I was thinking that perhaps the transponders that are still in the regular DVB-QPSK mode might have been chosen to avoid interferrence with the Mexican transponders, and/or avoid interferrence with the other polarity on the same sat, however after mapping the transponders that I can lock/not lock, I don't see any logic. But the pattern is still interesting. I've attached a little chart, where the green freqs are the ones that are still DVB mode.

Anyway, and interesting pattern, and I hope Genpix and TSREADER come out with new drivers soon, because even though most things are scrambled, it bugs me not to be able to lock the transponders.

OOPs... tried attaching an html, but apparently that file type isn't allowed as an attachment for some reason, so I've attached an excel sheet.

 

[Mr Tony]

BJ
In the last uplink report yesterday Dish changed 10 TP's over to Turbo QPSK
http://www.satelliteguys.us/2082216-post1.html

 

[B.J.]

BJ
In the last uplink report yesterday Dish changed 10 TP's over to Turbo QPSK
http://www.satelliteguys.us/2082216-post1.html

Thanks. Yeah, that agrees with what I was seeing. 2 gone before plus 10=12, leaving 4. Knocks out 3 fta channels for my Genpix.

 

[B.J.]

Thanks. Yeah, that agrees with what I was seeing. 2 gone before plus 10=12, leaving 4. Knocks out 3 fta channels for my Genpix.

Haven't checked in a couple weeks. Looks like 3 more transponders have gone over. Genpix webpage says they've fixed their firmware, but they haven't released it yet for SkyWalker-1, only for the -2 .