Archived from groups: alt.tv.tech.hdtv (
More info?)
Brian Hall wrote:
> On Time Warner Houston, I notice a distinct (probably two or three
> seconds) delay on my SA8300HD when compared to an analog tuner on a
> plain old TV connected directly to the cable, no cable box...
Right, and I explained below exactly how that can happen. David is
unwilling to accept my explanation (which is fine with me), perhaps you
are as well. If so, please feel free to extend your own explanation.
It's easy enough to check for yourself. Just put the SA box into its
diagnostic mode (while it's on) and go through the channels in question.
The diagnostic summary screen will tell you exactly what frequency the
box is receiving (in the RF section on the very first page), and it'll
even tell you if it is an analog signal.
On my system here, channels 3, 4, 5, 6, and 8 are all received in digital
on a frequency of 585MHz. All of the other low channels (2, 7, and 9
through 13) are received on their regular analog frequencies (ranging
from 57MHz to 213MHz). Adelphia is putting digital signals for five SD
channels into a single QAM broadcast, decoding them back into individual
channels once they get to my cable box.
When I tune those same channels 3, 4, 5, 6, and 8 from the same cable on
an analog TV, it receives them on their usual frequencies - 63, 69, 79,
85, and 182 MHz, respectively. So there's definitely a timing difference
between the two, and it's easy to see why.
You'll have to check for yourself to see what's going on on your system.
But I do suggest that you check for yourself rather than taking the
word of a service rep.
> In article <42a64717$0$1582$c3e8da3@news.astraweb.com>, Jim Gilliland
> <usemylastname@cheerful.com> wrote:
>
>
>>David Vanderschel wrote:
>>
>>>"Jim Gilliland" <usemylastname@cheerful.com> wrote in message
>>>news:<42a57b5b$0$26338$c3e8da3@news.astraweb.com>...
>>>
>>>
>>>>David Vanderschel wrote:
>>>>
>>>>
>>>>>Your experience with the satellite is not relevant,
>>>>>since we know there are delays going through DTV's
>>>>>system and space. The effect I am talking about is
>>>>>something that occurs entirely in the set top box
>>>>>after the signal gets to me.
>>>
>>>
>>>>Perhaps not. I don't know what cable system you're on or how they map
>>>>the channels, but here in my area Adelphia remaps the channels via their
>>>>SA8000 cable box. Yes, the regular analog channels are on the cable, so
>>>>I can watch our locals (3, 5, and 8) here on my regular TV just as you
>>>>do. But if instead, I tune those same exact channels (3, 5, and 8) on my
>>>>SA8000, I do NOT see the analog versions of those channels - instead, I
>>>>get the digital versions that Adelphia is broadcasting on a completely
>>>>different frequency. The SA8000 remaps the channel numbers internally.
>>>
>>>
>>>"Perhaps" is the operative word here. Your proposed
>>>theory does not apply in my case. Time Warner Austin
>>>does not replicate any of its analog channels in
>>>digital. (Many of us wish they would.)
>>>
>>>It seems that the thrust of most of the comments here
>>>has been to question the validity of my observation.
>>>It never occurred to me that folks would be so
>>>unwilling to believe. When I say that I am observing
>>>two different renderings of the SAME RF SIGNAL
>>>directly off the raw cable, I know what I am talking
>>>about. The delay is DEFINITELY occurring in the cable
>>>box. At least this sort of response reaffirms my
>>>feeling that this is mysterious behaviour - so
>>>mysterious that many folks are unwilling to believe
>>>that it is even happening.
>>
>>You asked for an explanation, and several of us provided reasonable
>>explanations that may, or may not, explain what you've observed. As for
>>whether or not you're actually observing what you think you are, I can't
>>say. However, I _can_ report that my SA box does not appear to have the
>>same behavior. And it appears that others here might have come to the
>>same conclusion. If yours is the only one that acts that way, and if
>>there's no good explanation for its behavior, then you might want to
>>consider other possibilities. But that's up to you.
>>
>>People are always going to trust their own observations over those
>>reported by others. That applies to the rest of us just as much as it
>>does to you.
>
>