HDTVFanAtic said:
Lyngsat, like the charts used for this thread, was done months ago.
They have since changed birds and the lyngsat info, like what was posted here - is seriously wrong and outdated.
I can't determine that any of the Lyngsat information regarding these two satellites is wrong. The uplinked channels lists for Spaceway 1 was submitted in December of 2005, and I have no reason to think it is in error. The frequencies of the six transponders used there was posted in June of 2006, but since I don't even know the correlation between frequency and transponder designation, I can't determine that information to be in error either.
The information regarding Spaceway 2 was posted and revised variously from April through June, 2006, but it does not include specific transponder frequencies. It may well have changed, but I have no way of determining that. Lyngsat is maintained by volunteers. If a person who is sufficiently motivated wants to revise the info and can satisfy Mr. Lyngemark that he is reliable, then he can become empowered to revise the information.
HDTVFanAtic said:
It is still mindboggling that they disabled the transponders in the bios. A major outage of one bird and many at D* will be out of work for making that decision. Just stupid to disable your redundancy as both E* and D* have experienced outages in the past.
Your concern is unfounded. DirecTV has two reasons to enable transponders: one is to test and adjust their coverage, and the other is to actually use them. DirecTV is presently undertaking an orderly process of incorporating 1,500 broadcast HDTV TV station's signals into its system. That entails setting up reception and processing hardware at its point-of-presence in each market, relaying the received signals to the chosen uplink facility, integrating the signals into transponder-width data streams and then uplinking them to the spot beam satellites. They also market, distribute and install the reception and processing hardware (AT9 antenna, MP4 receivers), which cannot be done all at once.
Once DirecTV has focused a beam so that they have optimized the trade-off between coverage of the market that is legally authorized to subscribe to the locals while minimizing the spill over into adjacent markets, they can shut the beams off and exclude them from the self-test regimen's display. If they ever have a beam failure on the new satellite, which is infrequent but it can happen, they already know what alternate routing they would use (these transponders are a lot more frequency agile than the earlier ones were) and if they actually needed to use a different spot to temporarily cover them during an outage, it could be turned on as needed, probably in a matter of seconds. Believe, me, these people know what they are doing. They know about a thousand times as much about what they are doing regarding this project as all of us together do.
We went through all this pontification over at DBSForums back when 4S was being analyzed. People didn't understand that the constraining factor on spot beam satellite capacity is the uplinking capacity, for example, and they thought that if their local spotbeam only had half a dozen channels in it, DirecTV was underutilizing it. They didn't understand that an uplink beam might have half a dozen of their locals and half a dozen of another market's in it, it was mirrored to two downlink spot beams, and in each market, the information regarding the channels that couldn't be legally subscribed to in each market was simply not incorporated into each guide, so there was nothing missing, just like when you toggle the "guide" button on a DISH remote between displaying the programs you don't subscribe to and excluding them.
DirecTV 4S can receive signals from just two uplink sites. Since DirecTV owns 32 transponders worth of Ku bandwidth at the 101 slot, for example, they have been allocated the same amount of uplink bandwidth in another frequency band. They can uplink 32 x 2 unique transponderwidth data streams, use 26 for CONUS programming, and still have 38 transponders available for local programming uplinking. 4S then "transponds" those signals to downlink them in 44 transponder-width beams directed at 27 geographic "spots". At the 119 degree slot, they own 11 transponders, can uplink from three sites (33 transponders), operate six as CONUS beams and then spot the programming of the remaining 27 (33-6) uplinked transponders at as many regions as is necessary to fully utilize the uplinked capacity. No one is being short-changed in that transaction, either. With Spaceway 1 and 2, and DirecTV 11 and 12, I think they receive programming from four uplink sites, and have a lot more frequency agility and beam re-aiming capability than do 4S and 7S.
I once explained much of this in a DBSForum's thread titled: "See spot. See spot beam quiz", but I think that thread got inadvertently lost when some work was done on DBSForum's data base. So much for all that bunk about everything we ever post being around forever.