Edinburgh digital

"wulfit" wrote in message
...
In fact I lost 23 channels - used to get 56, now get 33. I think the
vision on most of the channels that I do get is sharper as from today,
although it may be wishful thinking. BBC2 and BBC Alba have the best
reception.

The TV is tuned to a BT Vision box and the free to air aerial feeds into
the Vision box, and an HDMI cable attaches the TV to the BT box.
Re-tuning is done from and controlled by the Vision box, not the TV
itself. I would think that if the TV was directly tuned into the
available channels, then the Vision box would become a waste of time. The
secret appears to be having enough cables and ensuring that they all go
into the correct slots. I'm not sure if just the HDMI cable is enough.
Just to complicate matters, I have a DVD player/recorder, but I'd happily
disconnect it if it meant getting the extra channels. I know the HD works
properly because HD programs that I download from BT through their Vision
box are of superb quality, as are pre-recorded DVDs.

You must excuse me - I really am a novice at this, and I appreciate that
there are people in this forum who can advise me.

"Scott" wrote in message
...
On Wed, 15 Jun 2011 20:35:36 +0100, "wulfit"
wrote:

What a waste of time. Edinburgh did it's second switchover today and I
lost
about a dozen channels, and not an HD channel in sight. I'd rather go
back
to the old system. Being totally non-technical about it makes it
difficult.

If you provide details of what steps you have taken to perform a full
retune/rescan and difficulties encountered together with your postcode
I am sure the experts here will do their best to assist. I have found
them to be a helpful bunch of people.


There is no HD reception on a BT Vision box - I have one. In Duddingston I
receive 65 TV channels. My friend in North Berwick who has an HD TV and
receiver showed me al the HD channels working yesterday.

"Richard Tobin" wrote in message
...
In article ,
wulfit wrote:
In fact I lost 23 channels - used to get 56, now get 33. I
think the vision
on most of the channels that I do get is sharper as from today,
although it
may be wishful thinking. BBC2 and BBC Alba have the best
reception.

Unlike analogue, a better digital signal does not result in a
sharper
picture. If the signal is not good enough, the picture will
break up
in a very obvious way, typically with little rectangles of
colour.
Until that happens, the picture is as good as it can be.

-- Richard



Erm, yes and no. If the signal is poor the TV may well still
provide a steady unbroken picture, but what usually happens is
that the processor inside the TV (they are not TV's these days
but computers that think they are TV's) is working so hard
correcting the picture that the sound decoding will degrade
leaving the picture and sound out of sync. This will also often
happen if the picture appears good but the signal has phase
problems that on analogue may or may not be visible as ghosting.

Get a good solid direct signal and lip-sync will never be an
issue.



--
Woody

harrogate three at ntlworld dot com

On Wed, 15 Jun 2011 21:59:23 +0100, wulfit wrote:

In fact I lost 23 channels - used to get 56, now get 33. I think the vision
on most of the channels that I do get is sharper as from today, although it
may be wishful thinking. BBC2 and BBC Alba have the best reception.

The TV is tuned to a BT Vision box and the free to air aerial feeds into the
Vision box, and an HDMI cable attaches the TV to the BT box. Re-tuning is
done from and controlled by the Vision box, not the TV itself. I would
think that if the TV was directly tuned into the available channels, then
the Vision box would become a waste of time. The secret appears to be
having enough cables and ensuring that they all go into the correct slots.
I'm not sure if just the HDMI cable is enough. Just to complicate matters,
I have a DVD player/recorder, but I'd happily disconnect it if it meant
getting the extra channels. I know the HD works properly because HD
programs that I download from BT through their Vision box are of superb
quality, as are pre-recorded DVDs.

You must excuse me - I really am a novice at this, and I appreciate that
there are people in this forum who can advise me.

Does your TV have a digital tuner? If so, then you can use
that to receive DTV directly using an aerial connection. It
may even be capeable of decodong the HD channels.

I don't know the BT vision box but, based on the Humax box,
you may have to reset your box or do a scan with the aerial
disconnected to remove the old channel assignments stored
first to start with a clean sheet so you don't get any old
settings interfering with the new ones.

Also, because of the higher transmission levels after DSO,
you may now be able to see more than one transmitter and
this has "confused" your automatic rescan, especailiy if
you have a masthead amplifier. This is a known problem. -
I'm on Darvell and, during DSO, I was asked by my equipment
if I wanted Scotland or Central Scotland indicating I had a
choice.
--
John W

On Jun 16, 9:22*am, "Woody" wrote:
"Richard Tobin" wrote in message

...









In article ,
wulfit wrote:
In fact I lost 23 channels - used to get 56, now get 33. *I
think the vision
on most of the channels that I do get is sharper as from today,
although it
may be wishful thinking. *BBC2 and BBC Alba *have the best
reception.

Unlike analogue, a better digital signal does not result in a
sharper
picture. *If the signal is not good enough, the picture will
break up
in a very obvious way, typically with little rectangles of
colour.
Until that happens, the picture is as good as it can be.

-- Richard

Erm, yes and no. If the signal is poor the TV may well still
provide a steady unbroken picture, but what usually happens is
that the processor inside the TV (they are not TV's these days
but computers that think they are TV's) is working so hard
correcting the picture that the sound decoding will degrade
leaving the picture and sound out of sync. This will also often
happen if the picture appears good but the signal has phase
problems that on analogue may or may not be visible as ghosting.

Get a good solid direct signal and lip-sync will never be an
issue.

The lip-sync issues are down to inaccurate or drifting timing crystals
in STBs, and STBs that don't re-lock A/V sync based on MPEG-2 PTS
(presentation time stamps, which sync the audio and video and
everything else to a common clock - crap STBs ignore these and let
everything free-run).

In the case of some channels (especially HD sometimes) lip sync is out
on the broadcast. In the case of most modern TVs, the TV delays the
video (but less often, the audio).


Reception troubles can only cause lip-sync errors if your lousy STB
ignores PTSs and drops error'd audio or video frames independently.

Cheers,
David.

In article , Woody
writes

Erm, yes and no. If the signal is poor the TV may well still
provide a steady unbroken picture, but what usually happens is
that the processor inside the TV (they are not TV's these days
but computers that think they are TV's) is working so hard
correcting the picture that the sound decoding will degrade
leaving the picture and sound out of sync.

I'd be very surprised if error correction is not being done in dedicated
hardware, the algos are much better suited to hard wired (albeit
configurable) solutions. This mean no processor overhead no matter how
crappy the signal.
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********

In article , fred wrote:
In article , Woody
writes

Erm, yes and no. If the signal is poor the TV may well still provide a
steady unbroken picture, but what usually happens is that the processor
inside the TV (they are not TV's these days but computers that think
they are TV's) is working so hard correcting the picture that the sound
decoding will degrade leaving the picture and sound out of sync.

I'd be very surprised if error correction is not being done in dedicated
hardware, the algos are much better suited to hard wired (albeit
configurable) solutions. This mean no processor overhead no matter how
crappy the signal.

I'm also surprised by the idea that the RX uses its own two quite distinct
clocks for video and audio with no attempt to lock or reference them
together. I'd assumed the main clock reference would be provided by the MUX
stream itself since the audio and video are multiplex together into the
stream of frames of data.

But given how clumsy many other aspects of DTTV seem to be, maybe I should
not be surprised if this area, too, turns out to have been implimented
using the "dog's breakfast" approach to engineering. :-)

FWIW I've not yet bothered to rescan any of our RXs since this is a PITA,
and all we'd gain sic is Alba TV. I've given up on DVB-T for BBC Radio at
present. No point in a system that only works part of the time. Just causes
more bother. Shame for anyone who has no decent alternative to hand,
though.

Slainte,

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

On Thu, 16 Jun 2011 12:39:19 +0100, John Weston
wrote:

On Wed, 15 Jun 2011 21:59:23 +0100, wulfit wrote:

In fact I lost 23 channels - used to get 56, now get 33. I think the vision
on most of the channels that I do get is sharper as from today, although it
may be wishful thinking. BBC2 and BBC Alba have the best reception.

The TV is tuned to a BT Vision box and the free to air aerial feeds into the
Vision box, and an HDMI cable attaches the TV to the BT box. Re-tuning is
done from and controlled by the Vision box, not the TV itself. I would
think that if the TV was directly tuned into the available channels, then
the Vision box would become a waste of time. The secret appears to be
having enough cables and ensuring that they all go into the correct slots.
I'm not sure if just the HDMI cable is enough. Just to complicate matters,
I have a DVD player/recorder, but I'd happily disconnect it if it meant
getting the extra channels. I know the HD works properly because HD
programs that I download from BT through their Vision box are of superb
quality, as are pre-recorded DVDs.

You must excuse me - I really am a novice at this, and I appreciate that
there are people in this forum who can advise me.

Does your TV have a digital tuner? If so, then you can use
that to receive DTV directly using an aerial connection. It
may even be capeable of decodong the HD channels.

I don't know the BT vision box but, based on the Humax box,
you may have to reset your box or do a scan with the aerial
disconnected to remove the old channel assignments stored
first to start with a clean sheet so you don't get any old
settings interfering with the new ones.

I have a Humax box. I started an automatic scan then aborted it. This
cleared the channels without any need to disconnect the aerial.

Also, because of the higher transmission levels after DSO,
you may now be able to see more than one transmitter and
this has "confused" your automatic rescan, especailiy if
you have a masthead amplifier. This is a known problem. -
I'm on Darvell and, during DSO, I was asked by my equipment
if I wanted Scotland or Central Scotland indicating I had a
choice.

I had the same out of Blackhill. I assume the 'Scotland' was Darvel
and 'Central Scotland' Blackhill. Who thinks up these names? What is
the point of calling a transmitter 'Scotland'?

"John Weston" wrote in message
...
On Wed, 15 Jun 2011 21:59:23 +0100, wulfit wrote:

In fact I lost 23 channels - used to get 56, now get 33. I think the
vision
on most of the channels that I do get is sharper as from today, although
it
may be wishful thinking. BBC2 and BBC Alba have the best reception.

The TV is tuned to a BT Vision box and the free to air aerial feeds into
the
Vision box, and an HDMI cable attaches the TV to the BT box. Re-tuning
is
done from and controlled by the Vision box, not the TV itself. I would
think that if the TV was directly tuned into the available channels, then
the Vision box would become a waste of time. The secret appears to be
having enough cables and ensuring that they all go into the correct
slots.
I'm not sure if just the HDMI cable is enough. Just to complicate
matters,
I have a DVD player/recorder, but I'd happily disconnect it if it meant
getting the extra channels. I know the HD works properly because HD
programs that I download from BT through their Vision box are of superb
quality, as are pre-recorded DVDs.

You must excuse me - I really am a novice at this, and I appreciate that
there are people in this forum who can advise me.

Does your TV have a digital tuner? If so, then you can use
that to receive DTV directly using an aerial connection. It
may even be capeable of decodong the HD channels.

I don't know the BT vision box but, based on the Humax box,
you may have to reset your box or do a scan with the aerial
disconnected to remove the old channel assignments stored
first to start with a clean sheet so you don't get any old
settings interfering with the new ones.

Also, because of the higher transmission levels after DSO,
you may now be able to see more than one transmitter and
this has "confused" your automatic rescan, especailiy if
you have a masthead amplifier. This is a known problem. -
I'm on Darvell and, during DSO, I was asked by my equipment
if I wanted Scotland or Central Scotland indicating I had a
choice.
--
John W

I can either use the TV or the BT box to receive the free to air digital
signals but not both. If I tune in to DTV with the TV tuner, then I can't
use the box, and it has other features that I wish to keep using. The TV
has a dedicated HDMI channel, and I'm assuming this is the one I would use
as the base for tuning in the various channels being transmitted - but it is
currently tuned to the BT box.

For that reason, the aerial feeds in to the BT box and I have an HDMI cable
going from the box to the TV. I don't kow if that's the only connection I
need between the two, or if there are other cables that I should also be
attaching to improve the situation.

I do a re-scan every day. I certainly receive HD material through the On
Demand service, which is very nice, but I also want the HD free to air
channels.

"UnsteadyKen" wrote in message
m...

wulfit wrote...

The BT vision box allegedly has an inbuilt HD
receiver, but maybe I should call them to confirm.

I have a BT Vision+ box . It does not receive HD = (High Definition) TV;

It has twin standard definition SD tuners, though you can download HD
material.

it has got a built in HD = (Hard Drive) recorder which may be where the
confusion lies.

Have you carried out a rescan which is...

Settings / TV Settings / Add Channels to TV Guide?

While you are in there check that "Automatic Freeview Channel Updates"
is set to on.

--
Ken O'Meara
http://www.btinternet.com/~unsteadyken/

wulfit wrote:

For that reason, the aerial feeds in to the BT box and I have an HDMI
cable going from the box to the TV. I don't kow if that's the only
connection I need between the two, or if there are other cables that I
should also be attaching to improve the situation.

The BT box should (others who have it will confirm) have an RF loop-thru
output, that allows you to effectively connect another device with a tuner to
your aerial, in this case you TV. Then you can use the tuner in your TV to
view as well.


--
Mark
Please replace invalid and invalid with gmx and net to reply.

www.paras.org.uk