NASA-HD On G13

[BigRyan]

Trying to figure out if the end is finally here, Everything else seems good, but NASA on 3920/V/28068 has fallen below 50% as of lately. I'm afraid it might be my neighbors tree. Man I hate living in the city. Anyone else with a six foot dish experiencing 50% signal quality on NASA?

 

[BigRyan]

By the way, I'm getting 70% on another transponder (3760) at this location. So it might not be trees, although they aren't helping.

EDIT: Maybe the MPEG-4/UHD channel is taking all the bandwidth

 

[beavs2112]

BigRyan just a friendly reminder that NASA UHD is also in the 3780H30000 mux @ 101W.

 

[BigRyan]

BigRyan just a friendly reminder that NASA UHD is also in the 3780H30000 mux @ 101W.

If you don't mind me asking, are you receiving NASA from G13 right now, and if you are receiving it OK what size dish are you using for C-Band? Thanks.

 

[beavs2112]

If you don't mind me asking, are you receiving NASA from G13 right now, and if you are receiving it OK what size dish are you using for C-Band? Thanks.

Yes i am but the Q is low due to a tree and leaves blocking LOS. It's about 65% Q. My dish is a 10 foot Winegard Pinnacle on a home modified Paraclypse H-H mount.

 

[BigRyan]

Yes i am but the Q is low due to a tree and leaves blocking LOS. It's about 65% Q. My dish is a 10 foot Winegard Pinnacle on a home modified Paraclypse H-H mount.

Something else is going on here, since 2013 I have received it (both 105 and 127 locations) at 70% with my 6 foot solid and now I can't. I fell like they have cut power or reduced it for one reason or another.

 

[BigRyan]

So because I'm curious about stuff I wounder if anyone has answers to the following:

* Who controls transponder power levels, the company that owns the satellite or the company providing the uplink?
* Do the folks at NASA TV have control of this setting from a computer somewhere?
* Why would whoever controls this db setting ever reduce it, not enough solar power on the satellite?

I'm asking this because I would like to email, tweet, Facebook, instaSOMTHING, the parties involved and let them know. Maybe they are not aware of the problem. Something like this has happened before but it only lasted a few days, when these mugs were over on AMC18-C but it quickly came back.

I understand that NASA-TV is very special interest and its probably just me and two other dudes watching this channel but to anyone else reading this that can answer a few of my questions, even if you don't watch NASA I would greatly appreciate the incite.

 

[Titanium]

Many things come into play. One party is responsible for station keeping. This entails keeping the satellite in "the box" (the correct placement in the orbital position), load balancing, power management, signal carriage compliance, providing an optimized throughput, etc, The satellite bandwidth is booked via a "link budget", which are the details of the carriage agreement between the satellite owner/broker and the client. This link budget specifies the bandwidth, power level, service priority, etc. It basically states the requirements and responsibilities of both parties to maintain a specific level of service.

The station keeper typically only notifies the client (uplink) if the parameters exceed the carriage agreement. Usually the uplinker will not be notified if they are using less bandwidth or reduced power, etc. It is typically the uplink service provider that monitors the up/down signals to optimize to the link budget agreement. This may be automatic and the downlink is monitored and the uplink adjusted to maintain the specified parameters for power and bandwidth. Other uplinks are manual and the power is turned up down and the bandwidth fixed or shuffled between services on the transport stream.

The signal strength variations in the uplink/downlink are affected by conditions of the atmosphere (humidity, density, particulate), ionosphere (solar interaction) and even geomagnetic disturbances. The satellite position in the box moves the reception antennas in/out of the uplink signal lobe and if the satellite automatic gain is not activated or the uplink antenna is not optimized or power tracked the signal will increase/decrease as the satellite follows a figure 8 pattern.

If the downlink is not using an appropriate gain or efficiency dish, feedhorn, receiver as spec'd in the link budget, these variations may be much more noticeable. It may be that the signal is actually meeting the parameters of the link budget and everyone is doing their job, but the link budget has been contracted at a level that does not provide reliable service to non-complaint downlinks.

Probably best to simply state what satellite, service and when the programming is not reliable and provide your location, dish size, etc. This is rocket science and they may still have a few scientist remaining on staff... LOL!

 

[waylew]

Something else is going on here, since 2013 I have received it (both 105 and 127 locations) at 70% with my 6 foot solid and now I can't. I fell like they have cut power or reduced it for one reason or another.

Being a 6' not 2 degree compliant so prone to adjacent satellite interference,maybe something has changed on the "side"sats.Also with 6',less signal to combat "noise",possibly terrestrial interference has increased in your area.Just some thoughts.

 

[BigRyan]

Many things come into play. One party is responsible for station keeping. This entails keeping the satellite in "the box" (the correct placement in the orbital position), load balancing, power management, signal carriage compliance, providing an optimized throughput, etc, The satellite bandwidth is booked via a "link budget", which are the details of the carriage agreement between the satellite owner/broker and the client. This link budget specifies the bandwidth, power level, service priority, etc. It basically states the requirements and responsibilities of both parties to maintain a specific level of service.

The station keeper typically only notifies the client (uplink) if the parameters exceed the carriage agreement. Usually the uplinker will not be notified if they are using less bandwidth or reduced power, etc. It is typically the uplink service provider that monitors the up/down signals to optimize to the link budget agreement. This may be automatic and the downlink is monitored and the uplink adjusted to maintain the specified parameters for power and bandwidth. Other uplinks are manual and the power is turned up down and the bandwidth fixed or shuffled between services on the transport stream.

The signal strength variations in the uplink/downlink are affected by conditions of the atmosphere (humidity, density, particulate), ionosphere (solar interaction) and even geomagnetic disturbances. The satellite position in the box moves the reception antennas in/out of the uplink signal lobe and if the satellite automatic gain is not activated or the uplink antenna is not optimized or power tracked the signal will increase/decrease as the satellite follows a figure 8 pattern.

If the downlink is not using an appropriate gain or efficiency dish, feedhorn, receiver as spec'd in the link budget, these variations may be much more noticeable. It may be that the signal is actually meeting the parameters of the link budget and everyone is doing their job, but the link budget has been contracted at a level that does not provide reliable service to non-complaint downlinks.

Probably best to simply state what satellite, service and when the programming is not reliable and provide your location, dish size, etc. This is rocket science and they may still have a few scientist remaining on staff... LOL!

Titanium, your wealth of knowledge is unmatched in the industry. I will no doubt come back years from now and read this again and again, as I'm sure many will years to come. I did look at the Solar and Heliospheric Observatory Homepage and the LASCO/C3 looks fairly calm for, you know The Sun. But when you said "Link Budget" it all made since to me. I remember back when I was a cable installer TWC always had bandwidth allocation issues (yet those home shopping networks always stayed around) so I figured there was an allocation procedure of some type in place. I'm so glad you saw this and responded, now I have an understanding of what could be wrong.

Good news is today there is a slight improvement (i have a picture again) with lots of what I would call visible macroblocking and I have intermediate sound.

I would also like to add that this response was the most scientifically polite way ever to tell a guy his dish is "average" and he has nothing to worry about. LOL! Thanks for every thing you do!

 

[Cham]

I pick up NASA well using a dedicated 8 foot offset, but in order to get the other TPs of interest on G13 it is not as strong as it could be. Playing with the feed (F/D), skew, and scaler can make quite a difference, especially if there is an adjacent interfereing signal.

My observations of this TP (NASA) is that the signal is very consistant on my setup; various receivers and TBS-6903. Even holds during bad weather etc. Never really strong but always there.

 

[BigRyan]

I pick up NASA well using a dedicated 8 foot offset, but in order to get the other TPs of interest on G13 it is not as strong as it could be. Playing with the feed (F/D), skew, and scaler can make quite a difference, especially if there is an adjacent interfereing signal.

My observations of this TP (NASA) is that the signal is very consistant on my setup; various receivers and TBS-6903. Even holds during bad weather etc. Never really strong but always there.

What about today? I have lost it completely, It's gone...

Three years with 70% SQ, now nothing.

 

[Titanium]

3920V (SNR 13.2dB) , 3760V (14.6dB), 3780H (14.8dB) are all coming in fine in Northern California on a deep dish 10' and Titanium C2W-PLL.

 

[BigRyan]

3920V (SNR 13.2dB) , 3760V (14.6dB), 3780H (14.8dB) are all coming in fine in Northern California on a deep dish 10' and Titanium C2W-PLL.

 

[mc6809e]

The only dish I have here that currently has LOS to 127W is a 7½ft Unimesh with a C2W-PLL (and two damaged mesh panels that I haven't tried to repair yet). I generally get NASA with a quality of 71-72 on the A3's and 72-73 on the Alien2. Quality for AXS TV is usually 74-76 on the A3's. If I remember correctly, the quality from the 6ft dish was about 10 to 12 points lower for both channels, also using a C2W-PLL.

 

[Cham]

Ryan, here are the numbers from my 8' offset. The first one is the NASA mux, signal to noise ratio in bold. Also note the second TP on the same satellite on the opposite polarity overlaps, so if your skew is just a bit off NASA can be easily overwhelmed with interference from that second ACM TP. I did not scan adjacent satellites which can throw in a couple of additional sourced of interference. I did not optimize the NASA tp, but it always locks and plays fine, no breakups etc. This is likely due to their use of QPSK and a low FEC which are quite forgiving.
-Also note this is using a Geosat Pro C2 DRO LNBF.

EBSPro output:

Galaxy 13/C 127.0W 2330 TBS 6903 DVBS/S2 Tuner 0 3920 Vertical 28064.034 QPSK 3/4 DVB-S Auto 0.35 Normal CCM 38.794 37.886 (SNR)6.9 -27 MIS: 0, BER: 0.0000000, Time to lock: 435 ms 2017-05-18 7:15:53 AM

Galaxy 13/C 127.0W 2330 TBS 6903 DVBS/S2 Tuner 0 3928 Horizontal 10847.151 Auto Auto DVB-S2 OFF 0.35 Normal ACM 0.000 14.643 (SNR)4.9 -34 MIS: 1, BER: 0.0000000, Time to lock: 769 ms 2017-05-18 7:15:53 AM

Point being, antenna configuration is critical using less than optimum size reflector, and also anything in the receiver to antenna RF train has to be as good as possible too with such small reception margins.

 

[BigRyan]

First off, thanks to everyone for helping me research this problem. If it's not to much trouble I was wondering if Titanium could post the signal of 3920 again today so I can compare. Today I have a picture again.

 

[BigRyan]

Ryan, here are the numbers from my 8' offset. The first one is the NASA mux, signal to noise ratio in bold. Also note the second TP on the same satellite on the opposite polarity overlaps, so if your skew is just a bit off NASA can be easily overwhelmed with interference from that second ACM TP. I did not scan adjacent satellites which can throw in a couple of additional sourced of interference. I did not optimize the NASA tp, but it always locks and plays fine, no breakups etc. This is likely due to their use of QPSK and a low FEC which are quite forgiving.
-Also note this is using a Geosat Pro C2 DRO LNBF.

EBSPro output:

Galaxy 13/C 127.0W 2330 TBS 6903 DVBS/S2 Tuner 0 3920 Vertical 28064.034 QPSK 3/4 DVB-S Auto 0.35 Normal CCM 38.794 37.886 (SNR)6.9 -27 MIS: 0, BER: 0.0000000, Time to lock: 435 ms 2017-05-18 7:15:53 AM

Galaxy 13/C 127.0W 2330 TBS 6903 DVBS/S2 Tuner 0 3928 Horizontal 10847.151 Auto Auto DVB-S2 OFF 0.35 Normal ACM 0.000 14.643 (SNR)4.9 -34 MIS: 1, BER: 0.0000000, Time to lock: 769 ms 2017-05-18 7:15:53 AM

Point being, antenna configuration is critical using less than optimum size reflector, and also anything in the receiver to antenna RF train has to be as good as possible too with such small reception margins.

Thanks for giving specific details, I understand the Signal to Noise ratio but not sure what the -27 and -34 MIS means though. The crazy part for me is that nothing else has changed that I can see and I have always revived NASA at 70% signal quality. I don't seem to be having any other issues either. I keep coming back to trees with this problem, even though it look like LOS is ok, but I have to say its getting close these days. I will probably have to put in a dedicated dish to solve this problem for good. As for my current dish, I picked up 45W last night for the first time, and it's still tracking the arc nicely.

One more question, you also mention skew being just a bit off. I was under the impression that a motorized prime focus dish like I have would not have a skew. I have the LNBf skew at 0 (Zero) when on my true south satellite. I thought that as the dish moved across the arc the skew naturally happens. But I guess it still wont hurt to check what the skew should be for 127 where I live while the dish at 127. According to "http://www.dishpointer.com/" the LNB Skew should be 39.1° Turn clockwise standing behind the dish for 127W GALAXY 13.

 

[Titanium]

3920V Yesterday SNR 13.2dB / Today 12.9dB
3760V Yesterday 14.6dB / Today 14.2dB
3780H Yesterday 14.8dB / Today 14.4dB

To demonstrate Cham's information on the critical Xpol alignment, see this attached spectrum scan and compare the horizontal and vertical scans. Purple color is Horizontal polarity scan and Yellow is Vertical. If the polarity skew is not optimized, the opposite polarity carrier may interfere. Yes, on a fixed polarity install with no servo control of the polarity, it is usually set once and it will automatically track. But this doesn't provide an optimized setting for each satellite and polarity. A servo motor control of the polarity probe allows for adjustment on each satellite to provide an optimized setting for each polarity and is the best solution for reliable reception.

MIS = Multi-Input Stream. Multiple independent transport streams transmitted on a single transponder. Two transponders on 127w have flags for MIS, but only one TS is carried (3731 and 3928), both are ACM.

 

[BigRyan]

3920V Yesterday SNR 13.2dB / Today 12.9dB
3760V Yesterday 14.6dB / Today 14.2dB
3780H Yesterday 14.8dB / Today 14.4dB

To demonstrate Cham's information on the critical Xpol alignment, see this attached spectrum scan and compare the horizontal and vertical scans. Purple color is Horizontal polarity scan and Yellow is Vertical. If the polarity skew is not optimized, the opposite polarity carrier may interfere. Yes, on a fixed polarity install with no servo control of the polarity, it is usually set once and it will automatically track. But this doesn't provide an optimized setting for each satellite and polarity. A servo motor control of the polarity probe allows for adjustment on each satellite to provide an optimized setting for each polarity and is the best solution for reliable reception.
View attachment 126425

MIS = Multi-Input Stream. Multiple independent transport streams transmitted on a single transponder. Two transponders on 127w have flags for MIS, but only one TS is carried (3731 and 3928), both are ACM.

Alright so the signal for you is a little better today then yesterday and I seem to have a picture today.
Also by that screen cap It appears it can be hard to discern the desired signal from the undesired similar signals.
For the servo control, I'm guessing this is a mod or something I would have to build?
Thanks for always helping me out, I'm such a simple guy, grew up pulling engines out of cars with a come-along and a tree in the back yard. Hard to believe I have learned what I have, lol!