I am aware that Freeview is being pushed so that we can all go digital
ASAP but if Freeview can use an ordinary aerial with standard coax then
does this mean that the quality is less than satellite signal or are
they both the same when they come out of the set top box.

Are there any differences and should we be looking at a higher coax
quality for Freeview

Just wondering

Mike

On Sat, 4 Sep 2004 16:06:32 UTC, "Mike Saunders"
wrote:

I am aware that Freeview is being pushed so that we can all go digital
ASAP but if Freeview can use an ordinary aerial with standard coax then
does this mean that the quality is less than satellite signal or are
they both the same when they come out of the set top box.

Are there any differences and should we be looking at a higher coax
quality for Freeview

Depends on the signal strength. You might get away with the old style
coax in a very strong signal area, but there is no graceful degradation.
Any noise and you can lose the whole signal as it dips below the
threshold on digital.

A new antenna and downlead is meant to make quite a difference.

--
Bob Eager
begin a new life...dump Windows!

Bob Eager wrote:

On Sat, 4 Sep 2004 16:06:32 UTC, "Mike Saunders"
wrote:

I am aware that Freeview is being pushed so that we can all go
digital ASAP but if Freeview can use an ordinary aerial with
standard coax then does this mean that the quality is less than
satellite signal or are they both the same when they come out of
the set top box.

Are there any differences and should we be looking at a higher coax
quality for Freeview

Depends on the signal strength. You might get away with the old style
coax in a very strong signal area, but there is no graceful
degradation. Any noise and you can lose the whole signal as it dips
below the threshold on digital.

A new antenna and downlead is meant to make quite a difference.

I presume antennas do not degrade with time then so do you mean it is a
different spec for Freeview?

Also do you mean the downlead should be of satellite quality?

Thanks

Mike

On Sat, 4 Sep 2004 18:28:33 UTC, "Mike Saunders"
wrote:

A new antenna and downlead is meant to make quite a difference.

I presume antennas do not degrade with time then so do you mean it is a
different spec for Freeview?

Yes...maybe. I'm not a major expert on this (years since I studied
antennas) but one factor is that the antenna should incorporate a balun
to match the essentially balanced antenna to the unbalanced feeder.
Older antennas don't have this, but it's more important for digital, to
reduce noise picked up by the feeder. In addition, the channels used by
digital may not be in the same range as the ones your original antenna
was meant for. A wideband antenna seems to be the thing.

Also do you mean the downlead should be of satellite quality?

It needs to be properly screened (foil screen, not the 'low loss' wide
mesh stuff. I think this subject was rehearsed here recently.

There is some good stuff (and details of channels used by each mux, in
your area) at:

http://www.dtg.org.uk

The postcode checker is a little pessimistic, but you can then (when you
get the result page) find the transmitter in use and how far away, on
what bearing, and the channels in use. The link isn't very visble, but
it's the text "Link to information..." in the second shade box down on
the right of the postcode result page.

There are also documents that explain the antenna requirements in more
detail.

--
Bob Eager

On 4 Sep 2004 13:28:33 -0500, Mike Saunders wrote:

I presume antennas do not degrade with time ...

Bad assumption. They do, or at least the connections do, unless the
installer is very particular about sealing the cap and cable entry.
Most cheapo "contract" aerials will have water in the connection box
after the first shower of rain.

... then so do you mean it is a different spec for Freeview?

Depends where you are. In some places the Freeview Multiplexes are not
with in the same aerial group as the analogue transmissions, fitting
an aerial the properly covers the required frequencies will help.

Also do you mean the downlead should be of satellite quality?

CT100 has considerably less loss than bog standard "TV Coax". The less
signal you lose the better...

--
Cheers
Dave. pam is missing e-mail

"Mike Saunders" wrote in message ...
Bob Eager wrote:

On Sat, 4 Sep 2004 16:06:32 UTC, "Mike Saunders"
wrote:

I am aware that Freeview is being pushed so that we can all go
digital ASAP but if Freeview can use an ordinary aerial with
standard coax then does this mean that the quality is less than
satellite signal or are they both the same when they come out of
the set top box.

Are there any differences and should we be looking at a higher coax
quality for Freeview

Depends on the signal strength. You might get away with the old style
coax in a very strong signal area, but there is no graceful
degradation. Any noise and you can lose the whole signal as it dips
below the threshold on digital.

A new antenna and downlead is meant to make quite a difference.

I presume antennas do not degrade with time then so do you mean it is a
different spec for Freeview?

Also do you mean the downlead should be of satellite quality?

Thanks

Mike


If you look out the technical standards i believe that Sky via
satellite has a higher bit rate than terrestrial freeview, as the
available radio bandwidth is less limited, so it should be a better
picture. Also digital radio from satellite has a higher bit rate than
terrestrial DAB so the quality is better.

luggsie

luggsie wrote:

picture. Also digital radio from satellite has a higher bit rate than
terrestrial DAB so the quality is better.

Note that radio on freeview and DAB are unrealted technologies. Digital
radio on freeview tends to sound much better than DAB (which is to be
honest, crap!)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Mike Saunders wrote:
Bob Eager wrote:

On Sat, 4 Sep 2004 16:06:32 UTC, "Mike Saunders"
wrote:

I am aware that Freeview is being pushed so that we can all go
digital ASAP but if Freeview can use an ordinary aerial with
standard coax then does this mean that the quality is less than
satellite signal or are they both the same when they come out of
the set top box.

Are there any differences and should we be looking at a higher coax
quality for Freeview

Depends on the signal strength. You might get away with the old style
coax in a very strong signal area, but there is no graceful
degradation. Any noise and you can lose the whole signal as it dips
below the threshold on digital.

A new antenna and downlead is meant to make quite a difference.

I presume antennas do not degrade with time then so do you mean it is
a different spec for Freeview?

They do degrade over time, mainly due to effects of weathering.


Also do you mean the downlead should be of satellite quality?

All cables lose a bit of signal per metre. Higher quality cables have
less signal loss per metre than low quality cables. "Satellite quality"
cable tends to be higher quality.

So it all depends on how strong the signal is to begin with. All
satellite signals are fairly weak, which is why higher quality cable
should always be used with satellite. For terrestrial, it depends how
close you are to the transmitter, etc.

At my location I HAVE to use "satellite quality" cable (CT100) for
freeview or I can't get a reliable picture.

xenelk wrote:


All cables lose a bit of signal per metre. Higher quality cables have
less signal loss per metre than low quality cables. "Satellite quality"
cable tends to be higher quality.

True...

One of the main advantages of sat cable for Freeview is the extra noise
immunity that you get with the double screening on the cable. You can
have a freeview setup that has plenty of signal, but is plagued by
impulse noise from vehicle ignitions etc. Making sure all connections,
amps, splitters etc. are fully screened as well is a good plan.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article , xenelk
wrote:


So it all depends on how strong the signal is to begin with. All
satellite signals are fairly weak, which is why higher quality cable
should always be used with satellite. For terrestrial, it depends how
close you are to the transmitter, etc.

The screening is the reason for the cable requirement. Correct cable is
required even if (and probably more so) you are 2 miles from the
transmitter.

--
AJL Electronics (G6FGO) Ltd : Satellite and TV aerial systems
http://www.classicmicrocars.co.uk : http://www.ajlelectronics.co.uk

Andy Luckman (AJL Electronics) wrote:
In article , xenelk
wrote:


So it all depends on how strong the signal is to begin with. All
satellite signals are fairly weak, which is why higher quality cable
should always be used with satellite. For terrestrial, it depends how
close you are to the transmitter, etc.

The screening is the reason for the cable requirement. Correct cable
is required even if (and probably more so) you are 2 miles from the
transmitter.

Which was my point. I was just trying to explain it in simple terms....

In article ,
Mike Saunders wrote:
I am aware that Freeview is being pushed so that we can all go digital
ASAP but if Freeview can use an ordinary aerial with standard coax then
does this mean that the quality is less than satellite signal or are
they both the same when they come out of the set top box.

Satellite needs different cable because it's transmitted at much higher
frequencies. This makes no intrinsic difference to the end result.

--
*No sentence fragments *

Dave Plowman London SW
To e-mail, change noise into sound.

On Sat, 04 Sep 2004 19:45:01 +0100, Dave Plowman (News) wrote:

Satellite needs different cable because it's transmitted at much
higher frequencies.

cough Yes the downlinks are roughly 10.7 to 12.75GHz but the LNB on
the wok down converts that to 950MHz to 2.1GHz (ish). 950MHz is above
above Band IV/V so "TV Coax" wouldn't be particularly suitable.
However the satellite Tx frequency does not go down the cable from wok
to box.

--
Cheers
Dave. pam is missing e-mail

Dave Plowman (News) wrote:
In article ,
Mike Saunders wrote:
I am aware that Freeview is being pushed so that we can all go
digital ASAP but if Freeview can use an ordinary aerial with
standard coax then does this mean that the quality is less than
satellite signal or are they both the same when they come out of the
set top box.

Satellite needs different cable because it's transmitted at much
higher frequencies. This makes no intrinsic difference to the end
result.

Not down the cable it isn't.

The LNB on the dish downconverts the Gigahertz-range signal which comes
from the satellite into something very close to normal TV frequencies.

"Mike Saunders" wrote in :

I am aware that Freeview is being pushed so that we can all go digital
ASAP but if Freeview can use an ordinary aerial with standard coax then
does this mean that the quality is less than satellite signal or are
they both the same when they come out of the set top box.

Are there any differences and should we be looking at a higher coax
quality for Freeview

Just wondering

Mike


IMO freeview is not all it's cracked up to be. I get excellent picture and
sound quality, but there are annoying occasional very short sound losses.

This may be due to sporadic electrical interference from elsewher in the
hovel, but they don't warn you about it, and many boxes appear not to be
protected, and the system is clearly more vulnerable.

Also there are occasional pixilation artifacts on very busy pictures due
to bandwidth restrictions.

It is a way to get a picture across using less bandwidth, but having given
the broadcasters a bandwidth knob with digital techniques, they're happily
screwing it down all through the chain. (Look at the picture quality on BBC
24 hr news - 3 shades of pink, and textures otherwise achieved only by
cheapo camcorders).

You need a good aerial, and good downlead to minimise electrical
interference, because digital does not degrade politely like analogue, but
totally collapses.

I'd stay away from it if you have decent analogue; it may improve after the
switchoff, but not before

You could post in uk.tech.digital-tv for mor info; I doubt if it will help
but Bill the aerial man has a fund of good stories.

mike

mike ring wrote:


IMO freeview is not all it's cracked up to be. I get excellent picture and
sound quality, but there are annoying occasional very short sound losses.

some boxes handle this better than others have noticed. The oldish pace
DTVA fro example tends to introduce lots of clicks and squeaks when it
gets glitches in the signal. Something like the Netgem however handles
it much better.

This may be due to sporadic electrical interference from elsewher in the
hovel, but they don't warn you about it, and many boxes appear not to be
protected, and the system is clearly more vulnerable.

The QAM64 modulation scheme used on the ITV muxes is more vulnerable to
this than the QAM16 used on the other muxes.

Also there are occasional pixilation artifacts on very busy pictures due
to bandwidth restrictions.

It is a way to get a picture across using less bandwidth, but having given
the broadcasters a bandwidth knob with digital techniques, they're happily
screwing it down all through the chain. (Look at the picture quality on BBC
24 hr news - 3 shades of pink, and textures otherwise achieved only by
cheapo camcorders).

You need a good aerial, and good downlead to minimise electrical
interference, because digital does not degrade politely like analogue, but
totally collapses.

To be fair, it does not degrade at all right up until you reach the
threshold of the capabilities of the forward error correction used. At
that point it begins to suffer drastically. Subjectively that can be
more annoying if you only have a poorish signal, since the transition
between a perfect picture, and pixels, clicks, and frozen images is
more noticeable than a general covering of "snow" over what you are
trying to watch.

There are also some reception problems that digital is far better at
dealing with like multi path, (i.e. ghosting).

I'd stay away from it if you have decent analogue; it may improve after the
switchoff, but not before

Indeed, it ought to improve when more spectrum is made available. You
also need to factor whether any of the channels not available on
analogue are of value to you.

You could post in uk.tech.digital-tv for mor info; I doubt if it will help
but Bill the aerial man has a fund of good stories.

Yup that is true, well worth a visit for that if nothing else. (do a
google groups search on "riggers diary").


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote in
:

You
also need to factor whether any of the channels not available on
analogue are of value to you.

Har har.

mike

mike ring wrote:
John Rumm wrote in
:


You
also need to factor whether any of the channels not available on
analogue are of value to you.


Har har.

Why was that funny?


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Indeed, it ought to improve when more spectrum is made available. You
also need to factor whether any of the channels not available on
analogue are of value to you.

Also, analogue doesn't support widescreen. If you have a widescreen
television, or want to watch widescreen programmes on a 4:3 TV with black
bars top and bottom, then you'll need some sort of digital TV reception.

Christian.

On Mon, 6 Sep 2004 10:51:12 +0100, "Christian McArdle"
wrote:

Indeed, it ought to improve when more spectrum is made available. You
also need to factor whether any of the channels not available on
analogue are of value to you.

Also, analogue doesn't support widescreen. If you have a widescreen
television, or want to watch widescreen programmes on a 4:3 TV with black
bars top and bottom, then you'll need some sort of digital TV reception.

Christian.


... and thicker cable, or the pictures won't fit through it anyway.

When I was three or four, I asked my dad what the things with spikes
were for on people's roofs.

He told me, quite reasonably, that they were to pick up television
pictures - we had just got a set.

In those days, the old Band 1 H-shaped antennas were very commonplace,
so I naturally assumed that somehow the pictures were slotted into the
top, were perhaps rolled up to go down the cable and then appeared on
the screen - as if by magic. There was even a short film that was
shown about how television worked which showed something like this for
the transmission part so it never occured to me to think differently.

However, by the time I was about 8 or 9, this had all changed. I
can remember going to the public library and pulling out a book on how
to build a radio set. I took it to the counter and gave it to the
lady with my children's ticket (which was not meant to be for books
"for grown ups"). The librarian looked down her nose at me and
suggested that I would be better off with Janet and John or Noddy.
I explained to her that I could read the book perfectly OK. She asked
me to do so, which I did. Then thinking that she could catch me out,
asked me to explain how a radio worked. I closed the book and
explained how a superhet operated. She stamped the book and asked me
if I wanted any others like it.



..andy

To email, substitute .nospam with .gl

Andy Hall wrote:

"for grown ups"). The librarian looked down her nose at me and
suggested that I would be better off with Janet and John or Noddy.

Not as daft as it sounds though... When I was I guess about 10, I had a
Ladybird book called "How to build a transitor radio!" ;-)

ISTR it went through building a set in stages, starting with a basic
crystal set (using a OA91 diode for AM envelope demodulation - about the
last time I have used one of those), and then worked up to a
regenerative design. The construction method was a little "unorthodox"
with a wooden breadboard with a matrix of screws driven in, and the
wires of the components trapped under screw cups. Alas the full design
never did work, and I did not have access to the test equipment to trace
it through correctly to work out why. (not helped by being a very old
circuit design - many components were on the verge of being obsolete).


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

John Rumm wrote in message ...

There are also some reception problems that digital is far better at
dealing with like multi path, (i.e. ghosting).

I can vouch for this - I got a digibox for this reason alone. There is
a churchyard full of very old, very tall trees near my house. The
signal bounces off them causing quite bad ghosting on my analogue
signal. As the trees wave majestically in the breeze so the little
ghosts dance about on the telly. Anyway, the digibox has cured this
and gives a perfect signal on channels 1-4 despite running off an
aerial which looks like it may have been up there since the house was
built in 1880. The other channels can suffer from signal degradation
but they seem to broadcast unalloyed crap, so no loss there.

Mike Saunders wrote:

I am aware that Freeview is being pushed so that we can all go digital
ASAP but if Freeview can use an ordinary aerial with standard coax then
does this mean that the quality is less than satellite signal or are
they both the same when they come out of the set top box.

Assuming that you are getting adequate signal from both dish and aerial
then the main factor that will determine the picture quality is the
bitrate used to encode the channel.

Alas bit rates are often selected for commercial reasons (i.e. low
bitrate = more channels in a given bandwidth = more cost effective)
rather than aesthetic ones.

Freeview tends to give quite good picture quality on some channels - but
less so on the ITV muxes. It is less good on fast moving scenes (i.e.
football for example) where the bandwidth restrictions become more
noticeable.

Are there any differences and should we be looking at a higher coax
quality for Freeview

Something like CT100 cable will tend to give better results not only
because it is lower loss (hence more signal at the receiver), but also
it is less susceptable to picking up Interference (impulse noise in
particular) than traditional "low loss" co-ax.

The other thing to consider is that aerials do "age", in particular
co-ax absorbs water which will attenuate the signal. This is
particularly noticeable if your local region has channels allocated
toward the top of the spectrum where the absorption effect of the water
will be more noticeable.

Aerials can also degrade, due to mechanical damage accumulated over time
(birds, wind etc), and also corrosion. The larger higher gain aerials
tend to suffer more. Seven years is considered a good lifespan for a
high channel, high gain aerial.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

"Mike Saunders" wrote in message ...
I am aware that Freeview is being pushed so that we can all go digital
ASAP but if Freeview can use an ordinary aerial with standard coax then
does this mean that the quality is less than satellite signal or are
they both the same when they come out of the set top box.

Are there any differences and should we be looking at a higher coax
quality for Freeview

Just wondering

Mike

The boxes are now so cheap that I bought one just to try. There are
two TVs on the aerial and I found that a £5 amplifier from Asda (to
feed the digibox which is on the end of a few metres of cheap coax)
was the only upgrade that was required. The picture and sound quality
is never less than excellent and invariably better than the analogue
signal (whether compared against the amplified or unamplified signal).

MBQ

In article ,
MBQ wrote:
The picture and sound quality
is never less than excellent and invariably better than the analogue
signal (whether compared against the amplified or unamplified signal).

Hmm. On a *good* TV with a decent aerial, with the sound fed to an
external system, I'd defy anyone to reliably tell the difference between
analogue, NICAM, or Freeview - provided that source is mono.

Picture wise, pretty well the same applies (apart from aspect ratio) apart
from on the odd occasion the broadcasters are providing a superior source
than normal.

--
*Your kid may be an honours student, but you're still an idiot.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

Hmm. On a *good* TV with a decent aerial, with the sound fed to an
external system, I'd defy anyone to reliably tell the difference between
analogue, NICAM, or Freeview - provided that source is mono.

Alas the freeview can sound worse on the poor bitrate channels. With a
decent bitrate channel I have found it is about as good as NICAM when
fed into a prologic decoder. There also seems to be a fair variation in
sonic performance between the different freeview boxes.

Comparing against analogue is a little more trickey - as you say you
would have to limit your source material to mono which in many cases
will also mean older analogue recordings etc.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Dave Plowman (News) wrote:

In article ,
MBQ wrote:

The picture and sound quality
is never less than excellent and invariably better than the analogue
signal (whether compared against the amplified or unamplified signal).


Hmm. On a *good* TV with a decent aerial, with the sound fed to an
external system, I'd defy anyone to reliably tell the difference between
analogue, NICAM, or Freeview - provided that source is mono.

Picture wise, pretty well the same applies (apart from aspect ratio) apart
from on the odd occasion the broadcasters are providing a superior source
than normal.

I will second that. Ok the DVD's are a tad sharper, but otherwse my
analogue installation is almost totally free of defects and sharp and clean.

as is my FM radio...