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From: Joel Koltner on 1 Aug 2010 21:41
"Jim Thompson" <To-Email-Use-The-Envelope-Icon(a)On-My-Web-Site.com> wrote in
message news:fs6c5614fvsb404ao5l2brh9ml5nj56a1h(a)4ax.com...
> DTV = "Dumber TV" ?:-)

Something like that... I'm not sure the total "quality" of TV productoin has
risen much over time, whereas the number of channels certainly has, so the
"quality" ends off awfully thin on many a channel...

If you want to watch what I consider to at least be chortle-invoking TV,
there's at least Penn & Teller's "Bullshit!" on Showtime.

....which I actually don't subscribe to, but I do own the DVDs. Season six
(2008, I think --
http://www.amazon.com/Penn-Teller-Bullsh-Complete-Season/product-reviews/B001S86J0S )
was quite entertaining... folks who think dolphins are magical critters, the
green movement, sensitivity training, etc.

A surprising number of the folks who engage in these, mmm... "alternative
lifestyles" seem to prefer to live in your own state, for some reason :-).

Let me know if you'd like to borrow a DVD and I can send it down your way...

---Joel

From: Kevin McMurtrie on 2 Aug 2010 00:43
In article <8bm6dmF9dpU1(a)mid.individual.net>,
Joerg <invalid(a)invalid.invalid> wrote:

> Just curious: Why is it that "modern" TV/VCR/DVD devices only allow
> auto-scan for DTV channels but no "add some later"? As most of us know
> DTV is unreliable, meaning sometimes channel 6-1 pixelates out,
> sometimes 58-2 is gone. So upon setup it will only catch the ones that
> are currently receivable, which in our case is never more than 80% of
> digital channels. Changes all the time.
>
> But you can't add, it does a complete new setup, upon which Murphy says
> it'll miss a few channels it had detected on the previous run. That I
> find a rather daft technical decision. Is it just me thinking that or is
> the cleverness in electronics designs really taking a nose-dive?
>
> Sorry for the rant, but I had to let it out.

Some tuners will let you punch in the real channel in analog mode. For
example, I can type "4 5 ENTER" (no dash makes it analog) and it will
hop to 44-1. I use the trick to get Sacto stations that won't show up
in a scan but are viewable at night.

I wish I could delete obsolete mappings.
--
I won't see Google Groups replies because I must filter them as spam
From: Robert Baer on 2 Aug 2010 04:45
Joerg wrote:
> Just curious: Why is it that "modern" TV/VCR/DVD devices only allow
> auto-scan for DTV channels but no "add some later"? As most of us know
> DTV is unreliable, meaning sometimes channel 6-1 pixelates out,
> sometimes 58-2 is gone. So upon setup it will only catch the ones that
> are currently receivable, which in our case is never more than 80% of
> digital channels. Changes all the time.
>
> But you can't add, it does a complete new setup, upon which Murphy says
> it'll miss a few channels it had detected on the previous run. That I
> find a rather daft technical decision. Is it just me thinking that or is
> the cleverness in electronics designs really taking a nose-dive?
>
> Sorry for the rant, but I had to let it out.
>
Better yet, there should be a MANUAL ADD channel option...
From: Jan Panteltje on 2 Aug 2010 07:53
On a sunny day (Sun, 01 Aug 2010 18:01:01 -0700) it happened Joerg
<invalid(a)invalid.invalid> wrote in <8bmjmfFeq1U1(a)mid.individual.net>:

>> Sorry to hear that, I did read they improved multipath, maybe not enough.
>>
>
>It ain't good enough for multipath. Analog was better, way better.

Even PAL, that still gave a picture when it was almost 100% noise,
was sufficient perhaps to see what was 'going on', cannot compare in quality
to high bitrate DVB-T.


>>
>>>> You should now about PLLs, Viterbi decoding, etc.
>>>
>>> I do, but it seems the guys who developed and tested ATSC (or shall I
>>> say didn't test enough?) may not :-)
>>
>> Politics played some role there I am sure.
>> US had to use their own system.
>> OTOH they say the distances are bigger than in Europe, making 8VSB a better choice.
>> I have no experience with that system, so I dunno if that is reality.
>>
>
>It probably has other reasons as well. For example, people really want
>hi-def, meaning 1080 interlaced or progressive scan. And I have to say,
>if the channel doesn't pixelate out on us and a hi-def event like
>"Dancing with the Stars" airs the picture is truly stunning.

I do not see the connection between 8VSB and hi-def you are making?


>In the US we do not have free satellite :-(

Time to pack up and go Germany again :-)


>
>> I just watched starwars II, I have it on disc also, but it still is a big show.
>> My advice is to use a PC card and or PC as receiver, both for terrestrial and satellite.
>
>
>Nah. I just wired up this new Magnavox box. Like the one before it has
>upconversion and all that.
>
>A PC in the living room? Yuck. The most we ever do is connect one to
>watch photos, a laptop, via a VGA cable tucked behind a cabinet.

I have a small box for DVB-T (terrestrial), it has an USB connection.
ftp://panteltje.com/pub/haupppauge66.gif
I even installed a new kernel on the eeePC that can use it, so how big is that?
Of course the media centre PC is much bigger,
But many modern laptops have a HDMI output, would not be a problem, and you would be able to tweak things
in software.
Add an other box, a 1TB external harddisk.
Does not look so bad.


>> Duration : 3h 7mn
>> Bit rate mode : Variable
>> Bit rate : 3 586 Kbps
>> Nominal bit rate : 15.0 Mbps
>> Width : 720 pixels
>> Height : 576 pixels
>
>
>Hmm, we get a lot more resolution than that these days.

So do we, the same station is available in HD too, but I think it is encrypted, look for 'ProSieben HD':
http://nl.kingofsat.net/find.php?question=prosieben&Submit=Zap

Now the fun part is, they finally bought HD capable scanners it seems.
So now at least the normal 720p is top resolution (it always was low detail).
And free.
Unless you have 20/20 vision and a real big screen you cannot see the difference anyways :-)
So that saves money :-)
TV is far more advanced here, Sky will start broadcasting in 3D HD shortly.


>> As you see it is much longer than the movie, because of the commercials.
>> Because I view about an hour timeshifted I just fast forward the commercials,
>> or more precisely just jump over those in xine.
>>
>> The PC as media server is cool,
>
>
>Yeah, but you can do the same thing with a DVD recorder. Ok, time shift
>must be longer than the total play time including commercials. But that
>is never a problem because we watch one movie in the evening and that's it.

TV recording and processing with a PC has way more possibilities.
From: Paul Keinanen on 2 Aug 2010 09:18
On Sun, 01 Aug 2010 14:14:29 -0700, Joerg <invalid(a)invalid.invalid>
wrote:

>Just curious: Why is it that "modern" TV/VCR/DVD devices only allow
>auto-scan for DTV channels but no "add some later"? As most of us know
>DTV is unreliable, meaning sometimes channel 6-1 pixelates out,
>sometimes 58-2 is gone. So upon setup it will only catch the ones that
>are currently receivable, which in our case is never more than 80% of
>digital channels. Changes all the time.

You seem to suffer from frequency selective fading, which is typical
in multipath conditions. This may eliminate the signal with sharp
notches (usually less than 1 MHz) and these notches are constantly
moving around the TV band when the propagation condition changes.
Thus, a few channels are suffering from multipath nulls during each
channel scan and hence, these are not stored.

The 8VSB modulation used in ATSC is not known for robustness in
multipath situations. The help the situation, an equalizer is used at
the receiver that tries to compensate for the amplitude and phase
errors created by the RF path. The equalizer needs a known training
signal so that the equalizer parameters can be set up correctly. There
have been claims that with 5th (or was it 6th or 7th :-) generation
equalizers, the multipath performance is similar to COFDM DVB-T.

Apparently the 8VSB equalizer can somewhat track the slow RF-channel
parameter changes (starting the training session from previously known
good parameters), but during the initial channel scan, the equalizer
parameters are completely unknown for each new channel, the equalizer
is not capable of making any sense of some of the signals, even if the
amplitude is quite strong.

My guess is that if you connect a spectrum analyzer to your antenna
signal, it will show a comb filter like spectrum.

Diversity receivers are available in DVB-T countries mainly for in-car
receivers, but do you have diversity receivers for ATSC ?

Having two antenna towers at slightly different locations (at least
some wavelengths from each other) will have a different multipath
pattern. When one antenna and receiver drops out, the signal may be
good at the other antenna.

Even simple RF summing of two antenna signals at different locations
may help avoiding deep nulls.

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