Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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"Jan Panteltje" wrote in message
...
The one who calls himself rabbitsfriendsandrelations wrote:

Jan Panteltje wrote:

Eeyore wrote
Jan Panteltje wrote:
Spurious Response wrote

Right, I turned in a portable TV last week.
This one was about 30 years old (seventies), and was still working
OK,
but no analog transmissions here anymore, all you get is nice equal
distributed noise when tuning in to a digital station.

There are SEVERAL HDTV set top tuners out there that will pipe the
finished signal into a standard TV.

The boxes that are sold here are equipped with a SCART connector, a
waste.

I imagine you haven't looked very hard in that case. Many have UHF
outputs.

Graham

If you had as much as a clue, did not cut half the posting


I wasn't replying to the bits I trimmed.

Graham


To enlighten the others: to buy anything with any sort of analog output
sucks,
as analog is dead at least here in the Netherlands (except for audio).
Buying a settop box with USB output, if you have a laptop with USB,
creates the
portable TV with much better quality and recording possibility.
The USB settop box I bought runs from a 12 V adapter, so also from a car
battery.
I researched quite a bit to get the best deal, and SCART was not part of
that,
let alone a horrible interference prone, PAL coding artefacts decorated
UHF analog output.
ftp://panteltje.com/pub/dvb-t-nl.txt


You must have some rubbish kit over there then. A good PAL analogue TV set,
with a decent signal going in, beats a crappy highly compressed digital
signal, hands down, every time. If you want to talk about a picture
decorated in artefacts however, then digital is the hands down winner every
time in that category ...

Anyways, although your analogue terrestrial *transmissions* may have ceased,
I think it is unlikely that everyone in Holland has just thrown all of their
analogue-input ( both RF and composite ) portable TV sets and such in the
bin, and as long as that is the case, there will still be a need for
analogue outputs on other equipment such as STBs. Bear in mind also that an
analogue signal does not need to be UHF modulated, to be PAL encoded. One of
the default modes of the SCART standard is good old PAL-encoded analogue
composite video, both input and output.

Arfa


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On a sunny day (Thu, 26 Jul 2007 16:35:53 GMT) it happened "Arfa Daily"
wrote in :

To enlighten the others: to buy anything with any sort of analog output
sucks,
as analog is dead at least here in the Netherlands (except for audio).
Buying a settop box with USB output, if you have a laptop with USB,
creates the
portable TV with much better quality and recording possibility.
The USB settop box I bought runs from a 12 V adapter, so also from a car
battery.
I researched quite a bit to get the best deal, and SCART was not part of
that,
let alone a horrible interference prone, PAL coding artefacts decorated
UHF analog output.
ftp://panteltje.com/pub/dvb-t-nl.txt


You must have some rubbish kit over there then. A good PAL analogue TV set,
with a decent signal going in, beats a crappy highly compressed digital
signal, hands down, every time.


Well, maybe you do not have digital yet.
And for sure you have not seen the HDTV tests on satellite like those from France.
I am not denying mpeg2 compression has artefacts, but those very much depend on
bandwidth (bitrate), and bitrate is a bit less then 4000 kbps on digital here.
(non HD).
Although that is less then DVD max, it is absolutely enough for a stunning
_noise free_, _moire free_ (PAL & NTSC composite), _easy to record_ (as .ts),
_no loss editing_ (digital), _space saving_ (both on disk and in the ether),
allowing as many sub-channels as you like (more languages, more subtitles,
teletext, other services, timecode, all in the same stream).

It seems to me you do not _HAVE_ digital yet.
I have had digital sat now for about 7 years, and terrestrial for about a year.
As to range an signal to noise, I can get stations that I could only get
with a lot of noise and some reflections too in analog, now as clear as glass.
Really, only an inexperienced person would claim that composite PAL
in _whatever way_ was better.
And I know composite PAL better then many of you here, as I worked many years
at the source,
Even studio quality (directly from a PAL camera) has all sorts of artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)
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On Thu, 26 Jul 2007 17:10:00 GMT, in sci.electronics.design Jan
Panteltje wrote:


Even studio quality (directly from a PAL camera) has all sorts of artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)



Hmm, all the pro cameras I know come out in RGB or YUV.

Nobody in the professional world should be using PAL/NTSC in the
studio's primary signal chain today


martin
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martin griffith wrote:

On Thu, 26 Jul 2007 17:10:00 GMT, in sci.electronics.design Jan
Panteltje wrote:

Even studio quality (directly from a PAL camera) has all sorts of artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)


Hmm, all the pro cameras I know come out in RGB or YUV.

Nobody in the professional world should be using PAL/NTSC in the
studio's primary signal chain today


Interesting you should say that. There must be tons of gear out there that's
'legacy' so-to-speak PAL.

Graham

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On Thu, 26 Jul 2007 20:51:59 +0100, in sci.electronics.design Eeyore
wrote:



martin griffith wrote:

On Thu, 26 Jul 2007 17:10:00 GMT, in sci.electronics.design Jan
Panteltje wrote:

Even studio quality (directly from a PAL camera) has all sorts of artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)


Hmm, all the pro cameras I know come out in RGB or YUV.

Nobody in the professional world should be using PAL/NTSC in the
studio's primary signal chain today


Interesting you should say that. There must be tons of gear out there that's
'legacy' so-to-speak PAL.

Graham

I think you can still buy toy composite mixers, try BHphoto etc and
the camera control units (CCU) all had the usual PAL ScH and timing
adjustments, but rarely used, and don't forget that the (almost
obselete) Betacam SP format recorded in YUV anyway.

The PAL outputs are great for preview monitors, ie non critical, and
less wiring.

PAL is a very robust transmission format, but absolutely sucks in a
production setting


martin


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On a sunny day (Thu, 26 Jul 2007 22:55:42 +0100) it happened Chris Jones
wrote in :

You must have some rubbish kit over there then. A good PAL analogue TV
set, with a decent signal going in, beats a crappy highly compressed
digital signal, hands down, every time.


Actually I think you may be speaking some truth there.


No it is crap.

In the UK,

YUK


the video
bandwidth of the analogue PAL signal is wider than in other PAL countries,
which is why they had to move the sound subcarrier further from the vision
carrier, and which is why TVs couldn't be taken to/from the UK from/to
other PAL countries without some re-tuning,


Yea, well known, BBC, before it went brain dead, used to make nice pictures,
even had in the very old ages 4 tube cameras, I have been there, touched them,
had some interesting discussions with their techies.

Whatever you may think, compared to digital it sucks.
And that is digital done the right way, it makes no sense to
compare bad digital to HQ studio analog PAL as you do here when you talk
about some cheapo unspecified piece of consumer quality, about
some unspecified channels, sure you can get it as bad as you like.



until multi-standard chipsets
were introduced. It is very likely that he has never seen a PAL signal
with as much resolution as we get in the UK.


Idiot.


If you want to talk about a
picture decorated in artefacts however, then digital is the hands down
winner every time in that category ...



Yes, I borrowed a digital PVR from a friend and was not at all impressed.


Now that sure counts as a professional test.

Morons.

BYE
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Spurious Response wrote:
There are SEVERAL HDTV set top tuners out there that will pipe the
finished signal into a standard TV.


Really? Could I have a model number and manufacturer? Every source I've
seen says that to date there is absolutely no such thing in existence,
and is pessimistic about the appearance of such before the deadline
and/or at a price anywhere near the ridiculously low projections for
price of such items.

--
"Liberals used to be the ones who argued that sending U.S. troops abroad
was a small price to pay to stop genocide; now they argue that genocide
is a small price to pay to bring U.S. troops home."
-- Jonah Goldberg
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On a sunny day (Thu, 26 Jul 2007 23:06:19 +0100) it happened Chris Jones
wrote in :

Well, maybe you do not have digital yet.

Of course there is DVB-T in the UK, that's why we know from personal
experience that it looks worse than the old UK PAL system, that admittedly
does have a wider video bandwidth than what you would have been used to.


Well, tehre are some channels 9I can tell you as ican get all UK stuff here too
via satellite, tha tis ITV1-4 BBC- Parliament (if that is a channel), many more,
and soem of teh FTA Ky.

I have __***NEVER***__ seen 'noise stop', that is actually a sign of your
decoder not keeping up, I have noticed that some Sky channels transmit in
352x288 (the set will scale it to full) so at 1/4 the bandwidth, but you
cannot blame that on the digital system!!!!!! Blame it on Rupert!!!
You are not talking about a f*cking Skybox no?????????????????


And for sure you have not seen the HDTV tests on satellite like those from
France. I am not denying mpeg2 compression has artefacts, but those very
much depend on bandwidth (bitrate), and bitrate is a bit less then 4000
kbps on digital here. (non HD).

Perhaps they have throttled down the bitrate per channel in the UK to less
than they use where you are. I would like to see the numbers.


Exactly, there is, if you have a PCI card, some Linux program that shows
all the bitrates for the various streams in the transponders.
Cannot remember the name of the program, there are hundreds of utilities.


Or just someone who has seen both pictures and then tells the truth.


Sure, I do not question the observation, but I do say you need to compare
GOOD digital with GOOD PAL composite, else comparing makes no sense.

I
suspect that many people who have just spent a couple of grand on a new TV
feel that they have to say it looks better, because otherwise that would
make them stupid - so it's like the emperor's new clothes.


Yes those pople may exist, but normal people would return the set.

I say: Just buy a good digital set :-)

And then buy another one when they switch to MPEG-4, which they have already
proposed doing. Well by then it will have failed from tin whiskers anyhow.


That is why I am using a PC, no matter how they encode it, I will find
some decoder.

The public will keep buying new stuf fevery standard change say maybe even
more often then the lead-free requires.
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On a sunny day (Thu, 26 Jul 2007 23:13:52 +0100) it happened Chris Jones
wrote in :

Eeyore wrote:



Jan Panteltje wrote:

Spurious Response wrote

Right, I turned in a portable TV last week.
This one was about 30 years old (seventies), and was still working OK,
but no analog transmissions here anymore, all you get is nice equal
distributed noise when tuning in to a digital station.

There are SEVERAL HDTV set top tuners out there that will pipe the
finished signal into a standard TV.

The boxes that are sold here are equipped with a SCART connector, a
waste.


I imagine you haven't looked very hard in that case. Many have UHF
outputs.


I would like one which simultaneously decodes ALL OF the four main channels
(BBC1, 2, ITV, CH4) and then re-modulates ALL of them as PAL onto different
UHF frequencies, to basically recreate the old analog spectrum (albeit with
some MPEG artefacts...). I want one of these because I'm pretty sure that
I won't find a set top box that is as easy for my grandmother to use as the
four-position rotary switch that is on her present TV, and I don't want it
to be harder to use when the analogue transmitter is turned off. I think a
box like that would sell very well even for a high price, to the elderly or
basically to anyone who can't get that excited about a new modulation
method like these fanboys, but who just wants to watch TV. Perhaps when
the time comes I'll just have to buy 4 digiboxes and some splitters and
combiners and make one of these boxes. At least then all her elderly
neighbours could use it too, at the same time, so it might work out cheaper
as well.

Chris


On my PC I have voice control, I can just say:
show BBC1
show ITV1
show ARD
show RAIuno

and in a second or so (as the motorized dish moves to a different sat)
I have it on the 1680x1050 LCD (no not yet 1980).
All it needs is a PCI card and a satellite dish.

Your granny could do it, if she could find the power button on the PC
and monitor.


You can find the scripts on my website (Linux of course).
http://panteltje.com/panteltje/dvd/index.html
login with user 'guest' and password 'none' without the quotes.
http://panteltje.com/panteltje/dvd/show
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Glen Walpert wrote:
My nutshell summary of the published test results is that lead free is
significantly harder to do right than tin-lead, requiring tighter
process controls, but if done right it can be more reliable than
tin-lead for non-shock situations.


MORE reliable? Please elaborate.

--
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was a small price to pay to stop genocide; now they argue that genocide
is a small price to pay to bring U.S. troops home."
-- Jonah Goldberg


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martin griffith wrote:

Eeyore wrote:
martin griffith wrote:
Jan Panteltje wrote:

Even studio quality (directly from a PAL camera) has all sorts of artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)

Hmm, all the pro cameras I know come out in RGB or YUV.

Nobody in the professional world should be using PAL/NTSC in the
studio's primary signal chain today


Interesting you should say that. There must be tons of gear out there that's
'legacy' so-to-speak PAL.


I think you can still buy toy composite mixers, try BHphoto etc and
the camera control units (CCU) all had the usual PAL ScH and timing
adjustments, but rarely used, and don't forget that the (almost
obselete) Betacam SP format recorded in YUV anyway.

The PAL outputs are great for preview monitors, ie non critical, and
less wiring.

PAL is a very robust transmission format, but absolutely sucks in a
production setting


You would perhaps (or not) be amazed how much critical stuff like editing (for
feature films even- and I mean some really serious ones) is - or certinly was - done
from rushes that arrive on Beta SP tapes.

Given the huge investment in such kit I'd not be surprised if it's still quite
common.

Graham

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Arfa Daily wrote:


"Jan Panteltje" wrote in message
...
The one who calls himself rabbitsfriendsandrelations wrote:

Jan Panteltje wrote:

Eeyore wrote
Jan Panteltje wrote:
Spurious Response wrote

Right, I turned in a portable TV last week.
This one was about 30 years old (seventies), and was still working
OK,
but no analog transmissions here anymore, all you get is nice
equal distributed noise when tuning in to a digital station.

There are SEVERAL HDTV set top tuners out there that will pipe
the
finished signal into a standard TV.

The boxes that are sold here are equipped with a SCART connector, a
waste.

I imagine you haven't looked very hard in that case. Many have UHF
outputs.

Graham

If you had as much as a clue, did not cut half the posting

I wasn't replying to the bits I trimmed.

Graham


To enlighten the others: to buy anything with any sort of analog output
sucks,
as analog is dead at least here in the Netherlands (except for audio).
Buying a settop box with USB output, if you have a laptop with USB,
creates the
portable TV with much better quality and recording possibility.
The USB settop box I bought runs from a 12 V adapter, so also from a car
battery.
I researched quite a bit to get the best deal, and SCART was not part of
that,
let alone a horrible interference prone, PAL coding artefacts decorated
UHF analog output.
ftp://panteltje.com/pub/dvb-t-nl.txt


You must have some rubbish kit over there then. A good PAL analogue TV
set, with a decent signal going in, beats a crappy highly compressed
digital signal, hands down, every time.


Actually I think you may be speaking some truth there. In the UK, the video
bandwidth of the analogue PAL signal is wider than in other PAL countries,
which is why they had to move the sound subcarrier further from the vision
carrier, and which is why TVs couldn't be taken to/from the UK from/to
other PAL countries without some re-tuning, until multi-standard chipsets
were introduced. It is very likely that he has never seen a PAL signal
with as much resolution as we get in the UK.

If you want to talk about a
picture decorated in artefacts however, then digital is the hands down
winner every time in that category ...


Yes, I borrowed a digital PVR from a friend and was not at all impressed. I
don't like it when the numerical noise sometimes stays still and sometimes
moves. If they had not tried to cram so many channels of crap into the
bandwidth then they could have made it as good as the analogue system.
It's not like they have enough worthwhile programmes to fill even the
analogue channels, so they could have afforded the bandwidth.

Chris

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Jan Panteltje wrote:

On a sunny day (Thu, 26 Jul 2007 16:35:53 GMT) it happened "Arfa Daily"
wrote in
:

To enlighten the others: to buy anything with any sort of analog output
sucks,
as analog is dead at least here in the Netherlands (except for audio).
Buying a settop box with USB output, if you have a laptop with USB,
creates the
portable TV with much better quality and recording possibility.
The USB settop box I bought runs from a 12 V adapter, so also from a car
battery.
I researched quite a bit to get the best deal, and SCART was not part of
that,
let alone a horrible interference prone, PAL coding artefacts decorated
UHF analog output.
ftp://panteltje.com/pub/dvb-t-nl.txt


You must have some rubbish kit over there then. A good PAL analogue TV
set, with a decent signal going in, beats a crappy highly compressed
digital signal, hands down, every time.


Well, maybe you do not have digital yet.

Of course there is DVB-T in the UK, that's why we know from personal
experience that it looks worse than the old UK PAL system, that admittedly
does have a wider video bandwidth than what you would have been used to.

And for sure you have not seen the HDTV tests on satellite like those from
France. I am not denying mpeg2 compression has artefacts, but those very
much depend on bandwidth (bitrate), and bitrate is a bit less then 4000
kbps on digital here. (non HD).

Perhaps they have throttled down the bitrate per channel in the UK to less
than they use where you are. I would like to see the numbers.

Although that is less then DVD max, it is absolutely enough for a stunning
_noise free_, _moire free_ (PAL & NTSC composite), _easy to record_ (as
.ts), _no loss editing_ (digital), _space saving_ (both on disk and in the
ether), allowing as many sub-channels as you like (more languages, more
subtitles, teletext, other services, timecode, all in the same stream).

It seems to me you do not _HAVE_ digital yet.
I have had digital sat now for about 7 years, and terrestrial for about a
year. As to range an signal to noise, I can get stations that I could only
get with a lot of noise and some reflections too in analog, now as clear
as glass. Really, only an inexperienced person would claim that composite
PAL in _whatever way_ was better.

Or just someone who has seen both pictures and then tells the truth. I
suspect that many people who have just spent a couple of grand on a new TV
feel that they have to say it looks better, because otherwise that would
make them stupid - so it's like the emperor's new clothes.

And I know composite PAL better then many of you here, as I worked many
years at the source,
Even studio quality (directly from a PAL camera) has all sorts of
artefacts, just where the right striped shirt.

The more recent PAL TVs have fancy FIR comb filters that fix most of that
stuff. It is certainly less intrusive than the DVB-T artefacts, like noise
that freezes and then jumps and then freezes again.

I say: Just buy a good digital set :-)

And then buy another one when they switch to MPEG-4, which they have already
proposed doing. Well by then it will have failed from tin whiskers anyhow.

Chris

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Eeyore wrote:



Jan Panteltje wrote:

Spurious Response wrote

Right, I turned in a portable TV last week.
This one was about 30 years old (seventies), and was still working OK,
but no analog transmissions here anymore, all you get is nice equal
distributed noise when tuning in to a digital station.

There are SEVERAL HDTV set top tuners out there that will pipe the
finished signal into a standard TV.


The boxes that are sold here are equipped with a SCART connector, a
waste.


I imagine you haven't looked very hard in that case. Many have UHF
outputs.


I would like one which simultaneously decodes ALL OF the four main channels
(BBC1, 2, ITV, CH4) and then re-modulates ALL of them as PAL onto different
UHF frequencies, to basically recreate the old analog spectrum (albeit with
some MPEG artefacts...). I want one of these because I'm pretty sure that
I won't find a set top box that is as easy for my grandmother to use as the
four-position rotary switch that is on her present TV, and I don't want it
to be harder to use when the analogue transmitter is turned off. I think a
box like that would sell very well even for a high price, to the elderly or
basically to anyone who can't get that excited about a new modulation
method like these fanboys, but who just wants to watch TV. Perhaps when
the time comes I'll just have to buy 4 digiboxes and some splitters and
combiners and make one of these boxes. At least then all her elderly
neighbours could use it too, at the same time, so it might work out cheaper
as well.

Chris
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"clifto" wrote in message
...
Glen Walpert wrote:
My nutshell summary of the published test results is that lead free is
significantly harder to do right than tin-lead, requiring tighter
process controls, but if done right it can be more reliable than
tin-lead for non-shock situations.


MORE reliable? Please elaborate.


The reason that one might speculate this is that PbF solder has a higher
melting point and is harder, thus perhaps less prone to thermal damaged due
to cycling. This might be the case IF done right, but there are so many
variables that it is impossible to generalize this. The fact is that most
in the field realize that it is much easier to get it right with leaded
solder, and it is generally considered to be more reliable for most
applications. In fact, there are exemptions for critical applications that
allow leaded solder, even in the EU. The biggest problem that I have seen
in consumer electronics with PbF is that not enough solder is deposited in
the automated process of making the boards. This aften leads to an
unreliable joint. It is also harder to get good results in repairs with
PbF, as it requires higher temperatures and even the most freindly
formulations do not wet and flow as well.

Leonard




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Spurious Response wrote:

On Thu, 26 Jul 2007 02:37:53 +0100, Eeyore
wrote:



Spurious Response wrote:

Eeyore wrote:
Spurious Response wrote:

What is nice about digital broadcasts is that when you have the
signal, you have it all. No snow,
No herringbone patterns. Crisp and clean, with no caffeine.

Except when it breaks up.


Nope. If you tune the signal, you get ALL of the data. You must
exceed
more than ten percent bit error rate for a dropout to occur, and it is
bit error rate that matters most for a "tuned" channel.


I have a cable TV set top box. There's no tuning involved. It still breaks
up occasionally.


IT tunes itself, dip****.

Do you actually think I meant that you had a knob to turn?

Get your head out of your twenty year behind the digitally tuned
receiver world ass.

OK... I'll spell it out for you.

If it ACQUIRES the signal, and locks it in, it gets ALL packets from
the HEAVILY FEC coded stream, and can handle up to a 10% bit error rate
before the "tuning" starts to lose, and not be able to repair with the
FEC, data packets. When that happens, one starts to lose audio and or
video or could see some video artifacts. It usually results in short
term. low frame count dropouts.

So it isn't "breaking up". That is an analog expression. In digital
broadcast streams, the term is "dropout".


And then just when it gets to the interesting part of the programme you're
watching, outside it start raining. Then you get a few splutters of choppy
audio and a blue screen, then nothing at all, and you have to wait for it
to be repeated on analogue tomorrow.

Chris
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Jan Panteltje wrote:

On a sunny day (Thu, 26 Jul 2007 22:55:42 +0100) it happened Chris Jones
wrote in
:

You must have some rubbish kit over there then. A good PAL analogue TV
set, with a decent signal going in, beats a crappy highly compressed
digital signal, hands down, every time.


Actually I think you may be speaking some truth there.


No it is crap.

In the UK,

YUK


the video
bandwidth of the analogue PAL signal is wider than in other PAL countries,
which is why they had to move the sound subcarrier further from the vision
carrier, and which is why TVs couldn't be taken to/from the UK from/to
other PAL countries without some re-tuning,


Yea, well known, BBC, before it went brain dead, used to make nice
pictures, even had in the very old ages 4 tube cameras, I have been there,
touched them, had some interesting discussions with their techies.

Whatever you may think, compared to digital it sucks.
And that is digital done the right way, it makes no sense to
compare bad digital to HQ studio analog PAL as you do here when you talk
about some cheapo unspecified piece of consumer quality, about
some unspecified channels, sure you can get it as bad as you like.


Well I agree that there is no theoretical reason why the fact that the
signal is digital necessarily makes it look bad, for example the PAL
pictures that I have been watching were probably processed in the digital
domain through most of the signal chain before transmission.

What I am comparing is the end-user experience of watching a consumer grade
DVB-T receiver (in my case a Pioneer decoder), when compared to a
consumer-grade PAL receiver. In the end, if the picture quality is worse
USING THE EQUIPMENT AVAILABLE TO CONSUMERS, then that is all that counts.
I realise that a digital system with 300Mbits per second could be much
better than PAL, but what is being given to us is NOT better than PAL. By
all means they could build a good digital system, but that is not what this
is about. It is about freeing up as much spectrum as possible for auction,
whilst enabling the maximum number of channels of adverts to be transmitted
with a quality that is just good enough not to cause a backlash that would
result in people just turning off and watching a DVD.

until multi-standard chipsets
were introduced. It is very likely that he has never seen a PAL signal
with as much resolution as we get in the UK.


Idiot.

But surely you don't dispute that the channel bandwidth here is wider than
what you used to get?

If you want to talk about a
picture decorated in artefacts however, then digital is the hands down
winner every time in that category ...

Yes, I borrowed a digital PVR from a friend and was not at all impressed.


Now that sure counts as a professional test.

Well you just go and sit in your studio and watch your test cards then.
What actually matters is the picture quality that people (don't) get in
their homes.


Morons.

BYE

Whatever.
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Jan Panteltje wrote:

On a sunny day (Thu, 26 Jul 2007 23:13:52 +0100) it happened Chris Jones
wrote in
:

Eeyore wrote:



Jan Panteltje wrote:

Spurious Response wrote

Right, I turned in a portable TV last week.
This one was about 30 years old (seventies), and was still working
OK, but no analog transmissions here anymore, all you get is nice
equal distributed noise when tuning in to a digital station.

There are SEVERAL HDTV set top tuners out there that will pipe the
finished signal into a standard TV.

The boxes that are sold here are equipped with a SCART connector, a
waste.

I imagine you haven't looked very hard in that case. Many have UHF
outputs.


I would like one which simultaneously decodes ALL OF the four main
channels (BBC1, 2, ITV, CH4) and then re-modulates ALL of them as PAL onto
different UHF frequencies, to basically recreate the old analog spectrum
(albeit with
some MPEG artefacts...). I want one of these because I'm pretty sure that
I won't find a set top box that is as easy for my grandmother to use as
the four-position rotary switch that is on her present TV, and I don't
want it
to be harder to use when the analogue transmitter is turned off. I think
a box like that would sell very well even for a high price, to the elderly
or basically to anyone who can't get that excited about a new modulation
method like these fanboys, but who just wants to watch TV. Perhaps when
the time comes I'll just have to buy 4 digiboxes and some splitters and
combiners and make one of these boxes. At least then all her elderly
neighbours could use it too, at the same time, so it might work out
cheaper as well.

Chris


On my PC I have voice control, I can just say:
show BBC1
show ITV1
show ARD
show RAIuno

and in a second or so (as the motorized dish moves to a different sat)
I have it on the 1680x1050 LCD (no not yet 1980).
All it needs is a PCI card and a satellite dish.

Your granny could do it, if she could find the power button on the PC
and monitor.


You can find the scripts on my website (Linux of course).
http://panteltje.com/panteltje/dvd/index.html
login with user 'guest' and password 'none' without the quotes.
http://panteltje.com/panteltje/dvd/show



Thank you, that's helpful.

I still think it might not be for grandmothers, e.g. explaining why you
can't just unplug it when you're finished watching, etc. It would take me
a day of driving to go and replace a failed HDD, and whilst the local TV
shop can happily repair the analogue TV set, they might not be so hot on
reinstalling perl scripts. At least the start-up time would not be
unfamiliar, it would a reminder of waiting for the valves to warm up in the
set before the present one (which was still working when it was scrapped,
but it was 405 lines and B/W).

Chris
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"Jan Panteltje" wrote in message
...
On a sunny day (Thu, 26 Jul 2007 16:35:53 GMT) it happened "Arfa Daily"
wrote in
:

To enlighten the others: to buy anything with any sort of analog output
sucks,
as analog is dead at least here in the Netherlands (except for audio).
Buying a settop box with USB output, if you have a laptop with USB,
creates the
portable TV with much better quality and recording possibility.
The USB settop box I bought runs from a 12 V adapter, so also from a car
battery.
I researched quite a bit to get the best deal, and SCART was not part of
that,
let alone a horrible interference prone, PAL coding artefacts decorated
UHF analog output.
ftp://panteltje.com/pub/dvb-t-nl.txt


You must have some rubbish kit over there then. A good PAL analogue TV
set,
with a decent signal going in, beats a crappy highly compressed digital
signal, hands down, every time.


Well, maybe you do not have digital yet.
And for sure you have not seen the HDTV tests on satellite like those from
France.
I am not denying mpeg2 compression has artefacts, but those very much
depend on
bandwidth (bitrate), and bitrate is a bit less then 4000 kbps on digital
here.
(non HD).
Although that is less then DVD max, it is absolutely enough for a stunning
_noise free_, _moire free_ (PAL & NTSC composite), _easy to record_ (as
.ts),
_no loss editing_ (digital), _space saving_ (both on disk and in the
ether),
allowing as many sub-channels as you like (more languages, more subtitles,
teletext, other services, timecode, all in the same stream).

It seems to me you do not _HAVE_ digital yet.
I have had digital sat now for about 7 years, and terrestrial for about a
year.
As to range an signal to noise, I can get stations that I could only get
with a lot of noise and some reflections too in analog, now as clear as
glass.
Really, only an inexperienced person would claim that composite PAL
in _whatever way_ was better.
And I know composite PAL better then many of you here, as I worked many
years
at the source,
Even studio quality (directly from a PAL camera) has all sorts of
artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)


Of COURSE I have digital, foolish person. That is how I am able to comment
on this. I have had analogue satellite since it was first available as DBS,
and I changed over to digital as soon as that became available. I also still
take analogue from the terrestrial transmissions, and carry out repairs to
digital terrestrial STBs as part of my living, so I am able to compare all
standards at all times. I feed signals around my house at UHF, and have
perfectly clean signals at every TV - and there are a lot of them. As far
as HDTV signals go, they just about manage to get back up to the standard of
a *good* analogue transmission. As far as your opinion of my being
inexperienced goes, I have been directly involved with this stuff from the
service angle for 37 years. If that makes me 'inexperienced' in your eyes,
sobeit.

As for beat interference atrifacts from tweed jackets and loud ties, this
has not been much of a problem for years, since people in studios were
dressed properly for the job. Even so, I would still rather see a 'busy' tie
on a newsreader, than motion artifacts - both edge pixelation and motion
blur - any day of the week.

It's all very well saying that compression artifacts are a product of
available bandwidth, but that bandwidth is much limited with terrestrial
digital, if you want to pack in the number of channels that they seem to
want to. This allows for a perfectly satisfactory picture so long as it is
standing still, but does not if the bitrate needs to go up high enough to
prevent motion artifacts. For the most part, however, I would agree with you
that this is not an issue with the satellite transmissions, where the
limiting factor becomes how good a transponder, bit rate-wise, the station
can afford to lease.

Make no mistake, I am not trying here to compare a good digital signal - say
Sky Movies Premiere - with a poor noisy anlogue signal. What I am saying is
that the general public is being 'sold a pup' with the digital terrestrial
channels, where even the best quality transmissions, struggle to produce a
picture subjectively as good as that produced on a *good* analogue TV with a
*good* analogue PAL signal going in.

Arfa


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"Jan Panteltje" wrote in message
...
On a sunny day (Thu, 26 Jul 2007 22:55:42 +0100) it happened Chris Jones
wrote in
:

You must have some rubbish kit over there then. A good PAL analogue TV
set, with a decent signal going in, beats a crappy highly compressed
digital signal, hands down, every time.


Actually I think you may be speaking some truth there.


No it is crap.

In the UK,

YUK


the video
bandwidth of the analogue PAL signal is wider than in other PAL countries,
which is why they had to move the sound subcarrier further from the vision
carrier, and which is why TVs couldn't be taken to/from the UK from/to
other PAL countries without some re-tuning,


Yea, well known, BBC, before it went brain dead, used to make nice
pictures,
even had in the very old ages 4 tube cameras, I have been there, touched
them,
had some interesting discussions with their techies.

Whatever you may think, compared to digital it sucks.
And that is digital done the right way, it makes no sense to
compare bad digital to HQ studio analog PAL as you do here when you talk
about some cheapo unspecified piece of consumer quality, about
some unspecified channels, sure you can get it as bad as you like.



until multi-standard chipsets
were introduced. It is very likely that he has never seen a PAL signal
with as much resolution as we get in the UK.


Idiot.


If you want to talk about a
picture decorated in artefacts however, then digital is the hands down
winner every time in that category ...



Yes, I borrowed a digital PVR from a friend and was not at all impressed.


Now that sure counts as a professional test.

Morons.

BYE


I fear it is you who is the moron, my friend. It makes absolute sense to
compare a crap digital signal to a good analogue one, for the ones provided
by digital terrestrial are, for the most part, crap. This is in stark
contrast to the analogue terrestrial signals, which have always been of the
highest quality. The opinion of the poster on what he saw on a PVR, was not
intended to be seen as a 'professional' test, rather it was a subjective
test, which is what we have been talking here all along ...

Arfa




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Glen Walpert wrote:
On Tue, 24 Jul 2007 23:42:47 +0100, Eeyore
wrote:

The debate about lead free solders seem to be nearly as politically charged as
that about anthropogenic global warming and a casualty seems to be useful data.

I've read plenty of comments to the effect that lead-free is less reliable in
the long term (vibration seems to be a key weakness AIUI - maybe also thermal
cycling) which presumably explains the exemptions for certain categories, yet
I've also seen some studies that claim it can out-perform lead containing
solders.

Is there any real hard and fast information out there that one can rely on ?

Graham


Don't look to this newsgroup for factual info on lead free! Instead
look at actual test results in the trade publications such as SMT
magazine:
http://smt.pennnet.com/home.cfm
They have published numerous tests comparing various lead free
materials and processes with tin-lead. Some lead free materials and
processes are better than others (no surprise) and picking the best
one for your situation is non-trivial.

My nutshell summary of the published test results is that lead free is
significantly harder to do right than tin-lead, requiring tighter
process controls, but if done right it can be more reliable than
tin-lead for non-shock situations. Lead free is harder, stronger and
more brittle than tin-lead so tin-lead will deform plastically under
high shock when lead free will break, however lead free will withstand
more hot-cold cycles than before failure than tin-lead (better fatigue
resistance). So you need to know what the significant failure
mechanisms are in your design to pick the most reliable materials.

Glen


Another major issue is tin whiskers. We have hard evidence at
$WeBuildAvionics (where I am currently consluting) that the current Pb
Free / RoHS solder mixes have significant problems with growing
whiskers, leading to wonderful issues such as short circuits developing
under BGAs a few months after production. In a Flight control computer
(don't laugh - in a fly by wire environment it's the ONLY flight control
and virtually all late model airliners use it) this is Not a Good Thing
[tm].

The whole RoHS / Pb free thing is a political issue - the processes for
Pb Free use more hazardous substances than they get rid of.

Typical EU beauraucrats - unelected, overpaid and have to find something
to regulate to justify their existence. [1]

Cheers

PeteS

[1] Their existence, even from birth, might not be justifiable.
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On my PC I have voice control, I can just say:
show BBC1
show ITV1
show ARD
show RAIuno

and in a second or so (as the motorized dish moves to a different sat)
I have it on the 1680x1050 LCD (no not yet 1980).
All it needs is a PCI card and a satellite dish.


Aha ! So you are comparing wide bandwidth high bit rate satellite
transmissions, displayed on your high res PC screen, with an analogue PAL
signal. That is not quite the same as a low bit rate highly compressed
digital terrestrial transmission, displayed on an ordinary household TV set.
I do not have an issue with a setup such as yours producing comparable - or
even possibly superior in some instances - subjectively viewed pictures. But
that was not the comparison that I was making, when I voiced the opinion
that the digital pictures ( now being foisted on the public via the
terrestrial TV transmission network ) did not compare to the analogue PAL
pictures that we have been used to.

Arfa


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Another major issue is tin whiskers. We have hard evidence at
$WeBuildAvionics (where I am currently consluting) that the current Pb
Free / RoHS solder mixes have significant problems with growing whiskers,
leading to wonderful issues such as short circuits developing under BGAs a
few months after production. In a Flight control computer (don't laugh -
in a fly by wire environment it's the ONLY flight control and virtually
all late model airliners use it) this is Not a Good Thing [tm].

The whole RoHS / Pb free thing is a political issue - the processes for Pb
Free use more hazardous substances than they get rid of.

Typical EU beauraucrats - unelected, overpaid and have to find something
to regulate to justify their existence. [1]

Cheers

PeteS

[1] Their existence, even from birth, might not be justifiable.



It's good to hear at last from someone involved in the avionics industry,
and it's also good to hear that this particular industry is identifying
serious problems with the technology, as that might at least help to
maintain their exemption for some years to come. I really hope that the
industry has sufficient strength to stand up to this legislation, and to
continue to maintain their position of refusing to use it on safety /
reliability grounds. With my daily dealings with lead-free solder, and all
of the problems that it has brought to consumer electronics, the thought of
being held seven miles up in the sky by equipment using the same technology,
is truly worrying to me.

I cannot agree more that this whole thing is a poorly thought through
example of 'bandwagon politics' and job justification.

I would be interested in hearing any other input that you may have on the
subject, with regard to the avionics industry. Both anecdotal and factual
would be welcome, and I am sure that Graham (who started this thread) would
like see more from you, as well.

Arfa


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Arfa Daily wrote:

Make no mistake, I am not trying here to compare a good digital signal - say
Sky Movies Premiere - with a poor noisy anlogue signal. What I am saying is
that the general public is being 'sold a pup' with the digital terrestrial
channels, where even the best quality transmissions, struggle to produce a
picture subjectively as good as that produced on a *good* analogue TV with a
*good* analogue PAL signal going in.


I agree with you.

The same holds for DAB too.

Graham

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Spurious Response wrote:
wrote:
Spurious Response wrote:
What is nice about digital broadcasts is that when you have the signal, you
have it all. No snow,
No herringbone patterns. Crisp and clean, with no caffeine.


Except when it breaks up.


Nope. If you tune the signal, you get ALL of the data. You must exceed
more than ten percent bit error rate for a dropout to occur, and it is
bit error rate that matters most for a "tuned" channel.


I get regular breakups on cable, on multiple channels, at all times of day;
picture plus sound, picture only, and sound only. Picture loss includes
pixelization, cessation of action with partial pixelization, full loss of
action for seconds at a time. A visit from the cable company can fix that
for three or four days at a time.

The video reproduction is very reminiscent of the old 16-bit PC video
cards, especially in low-light scenes when it starts to look like the
video has about 16 brightness levels (four-bit video).

I used to get far better picture quality with rabbit ears from stations
a hundred miles or more away. I can take the snow when I don't have to
tolerate all the nasty artifacts in a digital picture.

--
"Liberals used to be the ones who argued that sending U.S. troops abroad
was a small price to pay to stop genocide; now they argue that genocide
is a small price to pay to bring U.S. troops home."
-- Jonah Goldberg


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On Thu, 26 Jul 2007 13:24:13 +0100, Eeyore
wrote:



Spurious Response wrote:

Eeyore wrote:
Spurious Response wrote:

So it isn't "breaking up".

Yes it 'breaks up'. Typically with weird pixellation.

That is an analog expression.

No it isn't.

In digital broadcast streams, the term is "dropout".

No, a dropout is a momentary LOSS of signal.


No. In HDTV broadcast, "dropout" is when a tuned station has more than
about 10% bit error rate, and the FEC cannot repair the data stream, and
everything from a few picture artifacts appears, to complete frame losses
(dropouts) occur. The picture artifacts are also dropouts, just not
those that cause the tuning device to display a blank screen for that
given frame, which they do when it gets beyond a certain point.

If they wanted to, they could show you the frames, and you would see
horrendous amounts of image artifacts, and likely audio problems as well.

It IS called dropout. Lost packets ARE lost "signal" as the packet would
not have been lost, were it not for the tuner's inability to reconstruct
any missing packet data from the FEC coding. This has been true from way
back in the early satellite receiver days.

Videocipher

http://en.wikipedia.org/wiki/Videocipher

Digicipher II (most closely related to the new HDTV broadcast schema).

http://en.wikipedia.org/wiki/DigiCipher_2

The current HDTV broadcast schema is also a General Instrument format,
now owned by Motorola.


Thanks for playing. It is like taking candy from a baby though.



You're an idiot, and have yet again said absolutely nothing.
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On Thu, 26 Jul 2007 20:51:59 +0100, Eeyore
wrote:



martin griffith wrote:

On Thu, 26 Jul 2007 17:10:00 GMT, in sci.electronics.design Jan
Panteltje wrote:

Even studio quality (directly from a PAL camera) has all sorts of artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)


Hmm, all the pro cameras I know come out in RGB or YUV.

Nobody in the professional world should be using PAL/NTSC in the
studio's primary signal chain today


Interesting you should say that. There must be tons of gear out there that's
'legacy' so-to-speak PAL.



Read it again. He said PROFESSIONAL, and NEWER equipment is inferred.
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On Thu, 26 Jul 2007 22:35:45 +0200, martin griffith
wrote:

On Thu, 26 Jul 2007 20:51:59 +0100, in sci.electronics.design Eeyore
wrote:



martin griffith wrote:

On Thu, 26 Jul 2007 17:10:00 GMT, in sci.electronics.design Jan
Panteltje wrote:

Even studio quality (directly from a PAL camera) has all sorts of artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)

Hmm, all the pro cameras I know come out in RGB or YUV.

Nobody in the professional world should be using PAL/NTSC in the
studio's primary signal chain today


Interesting you should say that. There must be tons of gear out there that's
'legacy' so-to-speak PAL.

Graham

I think you can still buy toy composite mixers, try BHphoto etc and
the camera control units (CCU) all had the usual PAL ScH and timing
adjustments, but rarely used, and don't forget that the (almost
obselete) Betacam SP format recorded in YUV anyway.

The PAL outputs are great for preview monitors, ie non critical, and
less wiring.

PAL is a very robust transmission format, but absolutely sucks in a
production setting


Spot on.

It is akin to a high end HD digital video card also carrying a composite
output jack.
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Spurious Response wrote:

Eeyore wrote:
martin griffith wrote:
Jan Panteltje wrote:

Even studio quality (directly from a PAL camera) has all sorts of artefacts,
just where the right striped shirt.

I say: Just buy a good digital set :-)

Hmm, all the pro cameras I know come out in RGB or YUV.

Nobody in the professional world should be using PAL/NTSC in the
studio's primary signal chain today


Interesting you should say that. There must be tons of gear out there that's
'legacy' so-to-speak PAL.


Read it again. He said PROFESSIONAL, and NEWER equipment is inferred.


Since when did PROFESSIONALS not use PAL ?

Don't talk about stuff you have no experience of. It makes you look even more
retarded than normal. I was the technical manager for an editing equipment hire
company some years back. I do know what I'm talking about.

Broadcast TV isn't as wealthy as it once was and don't expect equipment to be
'upgraded' on a whim.

PAL (and especially UK PAL) produces a far superior picture to NTSC btw just in case
you're getting confused.

Graham


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On Thu, 26 Jul 2007 16:18:00 -0500, clifto wrote:

Spurious Response wrote:
There are SEVERAL HDTV set top tuners out there that will pipe the
finished signal into a standard TV.


Really? Could I have a model number and manufacturer?


US Digital. WalMart. Made by Hisense, model DB-2010. ($200) Broadcast
only, NOT capable of the cable format. Ready for a single antenna,
multi-channel subscriber reception planned for the future in some cities.

Every source I've
seen says that to date there is absolutely no such thing in existence,
and is pessimistic about the appearance of such before the deadline
and/or at a price anywhere near the ridiculously low projections for
price of such items.


It has been out for over two years now, and it looks amazing on an old
standard set, not to mention on an actual HD set.

Broadcast digital reception is flawless, and should be the standard...
Oooops... to late... It is!

It has component out and composite, and SVHS.

Two channel audio only.

Great reception with either a standard set top antenna or a
preamplified unit, not to mention a rooftop job.

The "several" remark was just an assumption, but one would think that
others would include such a feature in their units.


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On Thu, 26 Jul 2007 16:39:50 -0500, clifto wrote:

Glen Walpert wrote:
My nutshell summary of the published test results is that lead free is
significantly harder to do right than tin-lead, requiring tighter
process controls, but if done right it can be more reliable than
tin-lead for non-shock situations.


MORE reliable? Please elaborate.



SHOCK.... and AWE!
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On Thu, 26 Jul 2007 23:31:48 GMT, "Arfa Daily"
wrote:

It's all very well saying that compression artifacts are a product of
available bandwidth, but that bandwidth is much limited with terrestrial
digital,



Both terrestrial broadcast, as well as satellite uplinks are 6MHz wide
STANDARD channel slots and transponder slots. That was one of the rules
of the game back when all this started.

So, on "terrestrial", one can expect the best picture, as it is "single
channel per carrier" (SCPC), whereas a satellite uplink from a service
provider is going to be a "multiple channel per carrier" (MCPC)
implementation, in 99.9999% of the cases.

Artifacts are a product of bit error rate. If the bit error rate of
your reception in zero, you WILL get ALL of the data.

The other source of artifacts are pre transmission compression.

In the old MCPC setup, only 6 or 10 channels per carrier could be
pumped, and it was an MPEG-2 compression schema and a 480i schema.

Now, they put up to 12 channels per carrier (per transponder) into the
uplink for 24 or 64 channels per transponder total.

With HDTV, much more data per frame needs to be dealt with. FEC is
your friend.
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On Thu, 26 Jul 2007 23:31:48 GMT, "Arfa Daily"
wrote:

For the most part, however, I would agree with you
that this is not an issue with the satellite transmissions,



Bull****. That is EXACTLY where the multiple channel per carrier thing
gets implemented.

In terrestrial schemes, it is only ONE channel per 6MHz wide carrier.

Your tuner may say that there are 3 PBS channels on the number 15, but
the actual frequencies of those channels are all on separate 6MHZ wide
slots with MAYBE only one which as actually on the channel 15 assigned
frequency.
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Spurious Response wrote:
On Thu, 26 Jul 2007 16:18:00 -0500, clifto wrote:
Really? Could I have a model number and manufacturer?


US Digital. WalMart. Made by Hisense, model DB-2010. ($200) Broadcast
only, NOT capable of the cable format. Ready for a single antenna,
multi-channel subscriber reception planned for the future in some cities.


Thanks. I'll have to take a look.

Broadcast digital reception is flawless, and should be the standard...
Oooops... to late... It is!


HDTV sucks, at least the little I've seen. The artifacts are too distracting
for me to watch the picture. When you can get a camera to stand still while
focused on a still object, so the compression isn't blurring everything,
there's improvement in sharpness and no snow and, if you're lucky, a
minimum of aliasing. When you get off the still life and start watching
conventional programming, the picture goes to hell. I watched a bit of a
football game while sitting in a furniture store and got a headache from
seeing the crowd go into and out of focus.

Great reception with either a standard set top antenna or a
preamplified unit, not to mention a rooftop job.


Wouldn't do me any good. I couldn't get a permit for the fifty-foot tower
I couldn't afford to put up. Far too many buildings between me and the
transmitting antennas at Sears Tower.

--
"Liberals used to be the ones who argued that sending U.S. troops abroad
was a small price to pay to stop genocide; now they argue that genocide
is a small price to pay to bring U.S. troops home."
-- Jonah Goldberg
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Spurious Response wrote:

"Arfa Daily" wrote:

For the most part, however, I would agree with you
that this is not an issue with the satellite transmissions,


Bull****. That is EXACTLY where the multiple channel per carrier thing
gets implemented.

In terrestrial schemes, it is only ONE channel per 6MHz wide carrier.

Your tuner may say that there are 3 PBS channels on the number 15, but
the actual frequencies of those channels are all on separate 6MHZ wide
slots with MAYBE only one which as actually on the channel 15 assigned
frequency.


'Arfa' is in the UK. There is no 'PBS' here.

We do have the BBC though, although it's been degraded terribly in the last few
years on the cross of 'political correctness'.

Graham




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Spurious Response wrote:
On Thu, 26 Jul 2007 16:39:50 -0500, clifto wrote:
Glen Walpert wrote:
My nutshell summary of the published test results is that lead free is
significantly harder to do right than tin-lead, requiring tighter
process controls, but if done right it can be more reliable than
tin-lead for non-shock situations.


MORE reliable? Please elaborate.



SHOCK.... and AWE!


Aw, not so shocking.

--
"Liberals used to be the ones who argued that sending U.S. troops abroad
was a small price to pay to stop genocide; now they argue that genocide
is a small price to pay to bring U.S. troops home."
-- Jonah Goldberg
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On Thu, 26 Jul 2007 23:31:48 GMT, "Arfa Daily"
wrote:

Make no mistake, I am not trying here to compare a good digital signal - say
Sky Movies Premiere - with a poor noisy anlogue signal. What I am saying is
that the general public is being 'sold a pup' with the digital terrestrial
channels, where even the best quality transmissions, struggle to produce a
picture subjectively as good as that produced on a *good* analogue TV with a
*good* analogue PAL signal going in.


You must be in a different multiverse location.

Satellite service gives you 300 plus channels by putting up to 12 6MHz
wide "channels" into each 6MHz wide slot.

http://www.tech-faq.com/mcpc.shtml

http://www.webopedia.com/TERM/M/MCPC.html
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On Thu, 26 Jul 2007 19:56:31 -0400, PeteS wrote:

Glen Walpert wrote:
On Tue, 24 Jul 2007 23:42:47 +0100, Eeyore
wrote:

The debate about lead free solders seem to be nearly as politically charged as
that about anthropogenic global warming and a casualty seems to be useful data.

I've read plenty of comments to the effect that lead-free is less reliable in
the long term (vibration seems to be a key weakness AIUI - maybe also thermal
cycling) which presumably explains the exemptions for certain categories, yet
I've also seen some studies that claim it can out-perform lead containing
solders.

Is there any real hard and fast information out there that one can rely on ?

Graham


Don't look to this newsgroup for factual info on lead free! Instead
look at actual test results in the trade publications such as SMT
magazine:
http://smt.pennnet.com/home.cfm
They have published numerous tests comparing various lead free
materials and processes with tin-lead. Some lead free materials and
processes are better than others (no surprise) and picking the best
one for your situation is non-trivial.

My nutshell summary of the published test results is that lead free is
significantly harder to do right than tin-lead, requiring tighter
process controls, but if done right it can be more reliable than
tin-lead for non-shock situations. Lead free is harder, stronger and
more brittle than tin-lead so tin-lead will deform plastically under
high shock when lead free will break, however lead free will withstand
more hot-cold cycles than before failure than tin-lead (better fatigue
resistance). So you need to know what the significant failure
mechanisms are in your design to pick the most reliable materials.

Glen


Another major issue is tin whiskers. We have hard evidence at
$WeBuildAvionics (where I am currently consluting) that the current Pb
Free / RoHS solder mixes have significant problems with growing
whiskers, leading to wonderful issues such as short circuits developing
under BGAs a few months after production. In a Flight control computer
(don't laugh - in a fly by wire environment it's the ONLY flight control
and virtually all late model airliners use it) this is Not a Good Thing
[tm].

The whole RoHS / Pb free thing is a political issue - the processes for
Pb Free use more hazardous substances than they get rid of.

Typical EU beauraucrats - unelected, overpaid and have to find something
to regulate to justify their existence. [1]

Cheers

PeteS

[1] Their existence, even from birth, might not be justifiable.



Damn. You actually made a post that I agree with 100%.

Seems one must fully encapsulate a finished assembly in transformer
varnish under vacuum to lock out the whisker growth.

Serviceability... right out the door.

Stink factor... worse than it was.

The whole ****ing thing stinks.
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On Thu, 26 Jul 2007 20:03:01 -0500, clifto wrote:

I get regular breakups on cable, on multiple channels, at all times of day;
picture plus sound, picture only, and sound only.



That is your fault for not calling them and complaining about your
obviously poor strength feed. That or the dopes actually think they can
send it out that way from the head end to everyone. That would be really
sad, and point toward the need for a class action suit. started at a town
meeting, and including the City Manager.
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On Thu, 26 Jul 2007 20:03:01 -0500, clifto wrote:

The video reproduction is very reminiscent of the old 16-bit PC video
cards, especially in low-light scenes when it starts to look like the
video has about 16 brightness levels (four-bit video).



That is referred to as "posterization".

Remember posters that were of "photos" or "pictures", but could only
give you a 16 color palette? Distinct lines of separation to "create" a
gradient.
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