examples of digital rip-off

In article ,
Ian Jackson wrote:

[Snip]

Point 2 is that a large number of cases (the majority, I believe)
majority are like Crystal Palace, ie the digital muxes will be in the
same aerial group as the analogues. When this is the case, provided that
the existing aerial is in good condition and the analogues are being
received OK, there is nothing to be gained by replacing the aerial (and
certainly not with a wideband aerial). It's just extra cost. 'If it
ain't broke, don't fix it' applies.

Indeed so. I'm still using my 'analogue' aerial - installed in 1978.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

In article , Bruce wrote:
As far as I am concerned, digital terrestrial is a huge improvement on
even the best analogue picture I have seen. In my experience, the
picture quality of digital satellite (BSkyB) is not as good as Freeview;
I have both.

Other people have different experiences, and I respect that. But making
dogmatic statements about analogue being fundamentally better than
digital isn't helpful, because it just isn't true.

Regardless of anyone's experience, it's a gross oversimplification just to
state that either digital or analogue terrestrial television is "better"
than the other, because there are a great many factors involved.

Being able to see the whole of the picture, for example, is surely a
parameter of quality, and as a decision seems to have been taken only to
transmit the whole of the 16:9 picture on digital, analogue is given an
unfair disadvantage straight away.

Then there's the deliberate bit-rate reduction which is applied in
variable amounts to the various digital channels. When the quality is good
it can be very good, but it can also be quite atrocious.

Then there are the effects of transmission and reception, and what happens
to the picture when conditions are less than perfect. The two systems
behave differently in response to these, and of course everybody's
situation will be different too.

And so on. What works well in one set of circumstances may not work in
another, but one thing that can be said as objective fact is that digital
signals have gone through an extra process that analogue signals haven't.

Rod.
--
Virtual Access V6.3 free usenet/email software from
http://sourceforge.net/projects/virtual-access/

"Dave" wrote in message
...
Bruce wrote:
Paul Martin wrote:
There are very occasionally rain storms which are so heavy that
there's
no signal whatsoever that gets through them. I've experienced that
one.


And they will affect analogue just as much as digital. ;-)

No, less so. FM has the advantage in bad weather. It's called the
capture effect. In the absence of another FM signal, it is possible to
get intelligible info from a weak signal. Albeit, you get a poor
picture. With digital, it just packs up below a certain signal level.

Dave



Er, Dave, go read your theory book again. Capture effect has nothing at
all to do with the weather although it is a feature of FM.

Capture effect is the ability of a receiver to 'hear' one signal and
suppress the effects a co-channel signal, usually on a signal strength
basis. It's a long time since I did the theory, but as I remember it, if
a tuner had a capture effect ratio of 2dB then it would suppress a
signal that was 2dB lower in strength usually by around 30dB - well, in
theory at least. If there is no other signal present capture effect does
not come into the equation.

And if you don't believe me look at
http://www.radio-electronics.com/inf..._reception.php

And why does FM come into picture quality since, in the UK, the video
signal is AM?


--
Woody

harrogate three at ntlworld dot com

On Fri, 20 Feb 2009 05:25:40 +0000 (GMT), charles wrote:

In article ,
Ian Jackson wrote:

[Snip]

Point 2 is that a large number of cases (the majority, I believe)
majority are like Crystal Palace, ie the digital muxes will be in the
same aerial group as the analogues. When this is the case, provided that
the existing aerial is in good condition and the analogues are being
received OK, there is nothing to be gained by replacing the aerial (and
certainly not with a wideband aerial). It's just extra cost. 'If it
ain't broke, don't fix it' applies.

Indeed so. I'm still using my 'analogue' aerial - installed in 1978.

Same here, probably of similar age.

I'm on Oxford, so wideband.
--
Peter.
You don't understand Newton's Third Law of Motion?
It's not rocket science, you know.

In message , Woody
writes
"Dave" wrote in message
...
Bruce wrote:
Paul Martin wrote:
There are very occasionally rain storms which are so heavy that
there's
no signal whatsoever that gets through them. I've experienced that
one.


And they will affect analogue just as much as digital. ;-)

No, less so. FM has the advantage in bad weather. It's called the
capture effect. In the absence of another FM signal, it is possible to
get intelligible info from a weak signal. Albeit, you get a poor
picture. With digital, it just packs up below a certain signal level.

Dave



Er, Dave, go read your theory book again. Capture effect has nothing at
all to do with the weather although it is a feature of FM.

Capture effect is the ability of a receiver to 'hear' one signal and
suppress the effects a co-channel signal, usually on a signal strength
basis. It's a long time since I did the theory, but as I remember it, if
a tuner had a capture effect ratio of 2dB then it would suppress a
signal that was 2dB lower in strength usually by around 30dB - well, in
theory at least. If there is no other signal present capture effect does
not come into the equation.

And if you don't believe me look at
http://www.radio-electronics.com/inf..._reception.php

And why does FM come into picture quality since, in the UK, the video
signal is AM?

Wasn't the rain affecting satellite signals? The analogues are FM.

And does this not depend on whether there's any AGC system? FM receivers
often don't rely simply on amplitude limiting. Also, limiting itself is
effectively a form of AGC (albeit crude). As the signal gets weaker, the
system overall gain winds up so that a constant signal level is
presented at the detector, and this brings up the noise level.

As long as the noise is well below the signal, the FM capture effect
suppresses the AM noise, and you get a 'clean' signal. However, when the
noise becomes nearly as strong as the signal, the recovered
signal-to-noise deteriorates rapidly. On FM video, that's when you get
the 'sparklies'. Below the 'knee' where the capture effect occurs, the
reduction of signal-to-noise is more-or-less inversely proportional to
the signal level.
--
Ian

Bruce wrote:
Ian Jackson wrote:
But is there any good analogue any more?


No, and there never was.

People tend to put on rose-tinted spectacles (and headphones!) when they
recall the "golden age" of vinyl records, analogue TV, Radio 1 on AM
(Medium Wave). My grandparents fondly remembered 78 RPM records and
didn't like new fangled 33.3 RPM vinyl LPs, even when played in stereo.
People just cling on to old things and feel threatened by anything new.

As far as I am concerned, digital terrestrial is a huge improvement on
even the best analogue picture I have seen.

Well I dont find that.

Sports is particularly irritating - you get compression artefacts round
all moving objects.

I think, but am not sure, that different sets handle this better or worse.



In my experience, the
picture quality of digital satellite (BSkyB) is not as good as Freeview;
I have both.


ONly have freeview.

Other people have different experiences, and I respect that. But making
dogmatic statements about analogue being fundamentally better than
digital isn't helpful, because it just isn't true.


It uses more bandwith and carries more information. This shows up.

Depending on how compressed the channel is, and how good the decoders,
it can be pretty horrible actually.

Dave wrote:
Bruce wrote:
Paul Martin wrote:
There are very occasionally rain storms which are so heavy that there's
no signal whatsoever that gets through them. I've experienced that one.


And they will affect analogue just as much as digital. ;-)

No, less so. FM has the advantage in bad weather. It's called the
capture effect. In the absence of another FM signal, it is possible to
get intelligible info from a weak signal. Albeit, you get a poor
picture. With digital, it just packs up below a certain signal level.

Dave

Well thats is not the way I have found it. Weak signals are better on
digital than on analogue. I have found that if the digital is
undisplayable, the analogue is usually a ghost lost noise almost completely.

Woody wrote:
"Dave" wrote in message
...
Bruce wrote:
Paul Martin wrote:
There are very occasionally rain storms which are so heavy that
there's
no signal whatsoever that gets through them. I've experienced that
one.

And they will affect analogue just as much as digital. ;-)
No, less so. FM has the advantage in bad weather. It's called the
capture effect. In the absence of another FM signal, it is possible to
get intelligible info from a weak signal. Albeit, you get a poor
picture. With digital, it just packs up below a certain signal level.

Dave



Er, Dave, go read your theory book again. Capture effect has nothing at
all to do with the weather although it is a feature of FM.

Its only a feature of wideband FM.

And IIRC the analogue video is AM antyway, not FM.

Mike Henry wrote:
In , Bruce
wrote:

In my experience, the
picture quality of digital satellite (BSkyB) is not as good as Freeview;
I have both.

Did you have both before Easter 2000?


No, Freeview is more recent than that. Freeview was launched in October
2002, so to have both before then would have been impossible.


The bitrates on DSAT for the BBC in
particular used to be far higher, then they dropped them dramatically.


Isn't that because the BBC changed to a separate feed to the Astra
satellite that doesn't go via Sky's ground station? Sky have kept BBC
on the Programme Guide for the convenience of Sky subscribers but the
main BBC channels are free-to-air via the same Astra satellite.

Bruce wrote:
Mike Henry wrote:
In , Bruce
wrote:

In my experience, the
picture quality of digital satellite (BSkyB) is not as good as
Freeview; I have both.

Did you have both before Easter 2000?


No, Freeview is more recent than that. Freeview was launched in
October 2002, so to have both before then would have been impossible.

That's just a name change, DTT has been around a lot longer.
--
There's probably no god, so stop worrying and enjoy your life.