7 Missing Channels in London

Discussion:

(too old to reply)

DJC

2006-11-07 15:32:02 UTC

Hello Folks,

I have just moved from SE london to SW london and i have retuned my TV (my
card is a leadtek 2000 hybrid) and now i am missing 7 channels including the
ITV's
When i did the first scan they were there but now after another scan(s) they
are gone.
I am telling MCE to use crystal palace transmitter .. Any Ideas ?

I am trying to find out how to edit the registry to only use the specific
transmitter as discussed in
http://thegreenbutton.com/forums/thread/133114.aspx

Nigel Barker

2006-11-08 07:00:37 UTC

Permalink

Post by DJC
Hello Folks,
I have just moved from SE london to SW london and i have retuned my TV (my
card is a leadtek 2000 hybrid) and now i am missing 7 channels including the
ITV's
When i did the first scan they were there but now after another scan(s) they
are gone.
I am telling MCE to use crystal palace transmitter .. Any Ideas ?
I am trying to find out how to edit the registry to only use the specific
transmitter as discussed in
http://thegreenbutton.com/forums/thread/133114.aspx

Sounds like a poor signal. You may need a new decent aerial or it may be
sufficient to use a cheap signal booster (about 10 pounds in Argos).

Editing the registry to just use your local transmitter is a good idea as it
drastically reduces scanning time.

--
Nigel Barker
Live from the sunny Cote d'Azur

Nigel Barker

2007-01-05 09:53:11 UTC

Permalink

On Thu, 4 Jan 2007 13:58:01 -0800, Matt Costello <Matt

Hi
I am in brighton and have the same problem. ITV / C4 and a load of others
have just dissapeared a month or so ago - they were working fine for over a
year. I have tried a booster and in the end went out and bought a cheapo
freeview receiver to check my signal and this cheapo box scans loads quicker
plus picks up ALL the channels (more than MCE ever did even when it was
working properly!). It's as if one of the windows updates changed the
threashold signal strength at which it will add the channel to the guide. If
my freeview box for 20 quid can work, why doesn't my MCE at over 800 quid
work!!!

The DVB-T (Freeview) PC cards seem less sensitive than any external Set Top Box.
On the off chance that it is a software problem use Mark Salloway's excellent
MCE Reset Utility to return MCE to a virgin state & then run through the
complete setup again
http://www.salloway.org.uk/MediaCenter/util/index.htm

--
Nigel Barker
Live from the sunny Cote d'Azur

Nigel Barker

2007-01-06 12:15:38 UTC

Permalink

On Fri, 5 Jan 2007 01:55:00 -0800, Matt Costello

Hi Nigel
Thanks for such prompt reply!
I'll give those apps a try. Currently I have 2 x Hauppauge pci BVB-T box
standdard cards that came with my Elonex Artisan. I tried removing 1 and
swapping them around last night, did get a few more channels at 1 point, but
still not itv & c4. the cards don;t look anything special and the date on
them is 2004 so i guess things may have moved on since then. I think i might
http://www.hauppauge.co.uk/pages/products/data_novat500.html
and see what effect that has. It's supposed to have more sensitive tuners.
I'll let you know how I go.
Cheers.
Matt

It's almost certainly a marginal signal problem especially as the number of
channels found on a scan varies at different times. You may need to invest in a
decent outdoor aerial.

The dual tuner Nova-T 500 will only save you a PCI slot. I have not heard that
it's sensitivity is any better than the single tuner Nova-T

One last hope is that the DVB-T (Freeview) support in MCE can be flakey at the
best of times. For example every time it tunes to a MUX it scans to see if any
channels have disappeared or new ones appeared. If the signal is a bit iffy it
may think that e.g. BBC FOUR has stopped broadcasting & remove it conversely if
it picks up a different channel ident for an existing channel it will add what
it thinks is a new channel. This so-called opportunistic scanning is at the root
of most problems with DVB-T. It also emphasises the importance of a good signal.

You can also get problems when MCE tunes in to a weaker signal from a more
distant transmitter rather than stronger signal from your local transmitter.
By judicious editing of the registry you can force MCE to only scan the six
MUXes from the nearest transmitter. It also greatly decreases the amount of time
that a scan takes. There is a detailed description of how to do it in this
posting http://thegreenbutton.com/forums/thread/133114.aspx

--
Nigel Barker
Live from the sunny Cote d'Azur

John Lockwood

2007-01-08 10:24:41 UTC

Permalink

On 4/1/07 21:58, in article

The only times I have been missing channels on DVB-T have been due to poor
signals. I am using the tiny indoor aerial included with my Terratec Cinergy
T2 receiver which strictly speaking is not good enough for UK use, however
if I position it carefully I can get a good enough signal to get all the
channels.

The fact that all/most of the missing channels are ITV suggests they could
all be in the same multiplex (or two multiplexes) which would be consistent
with this theory. The other possibility is that the frequency of that
multiplex(es) is not being scanned, however my belief is that is controlled
by the MCE software not the hardware tuner (that is what frequencies to
scan) so that would be unlikely.

Finally, it is fact that not all DVB-T transmitters are created equal. My
transmitter in South West London is Crystal Palace and has more channels
than any other (including the BBC HD trial channel!) but the one for Farnham
where I work has fewer available channels.

This page may be of interest http://www.ukfree.tv/txdetail.php?a=TQ330045 it
confirms all the channels you are missing are in Multiplex 2 (E4+1 is in
Multiplex C) it also indicates that the signal strength of Multiplex 2 is
weaker than Multiplex 1 (the BBC one) and Multiplex C.

Hmmm, just read some more info from that site and the ITV Multiplex uses
64QAM (which is why it is weaker) whereas most of the others use 16QAM, I
suppose this could also possibly mean your tuner does not support 64QAM,
unlikely but you could ask them. See
http://www.ukfree.tv/fullstory.php?storyid=1107051058&sid=2&subid=0

Note: they all work with my tuner.

Pinakin Patel

2007-03-05 21:16:44 UTC

Permalink

Hi Matt,

I live in Brighton too and my ariel is an outdoor one on top of a purpose
built block of flats. I lost ITV1,2 and 3 plus C4 about two months ago. The
channels were very poor in quality before I retuned it to pick up the new C5
channels. But I can not pick the channels anymore. I'm going to get a signal
booster to see if that helps. Not sure what I can do now though. Why spend a
grand on an MCE machine that needs constant rebooting when I could have got a
£20 freeview box.

Stibbs

2007-01-25 09:53:00 UTC

Permalink

Interesting...

I have two Nova-t 500's running from the same arial, now one will pick up
all channels and the other will pick up everything with the one exception of
the ITV channels (ITV1, ITV2, ITV3, Channel 4 etc.)

I can swap the cables around and it makes no difference, the odd thing is
the card I expected to get the trouble (outer part of the arial socket makes
contact with my case) I get all channels the one which I thougt would be best
fails on the ITV front.

I have read about the same issue using the same card on Linux so I am
inclinded to thing its more of an hardware issue than drivers etc.

I am 100% confident its not a signal issue as I had the arial replaced
because of bad signal when I was running two Twinhan DVB-T cards with a
signal booster. I now get 100% quality and 80-90% strength on both inputs.

My investigations are final but I am trying at least the following:
- Swapping the cards in the PCI slots
- Check IRQ, DMA conflicts
- Check USB bandwidth availability
- Make the outer case of the arial socket make contact with the case

I will get back to you regarding this as I already have one tunner working I
must be able to get both unless there are hardware issues.

John Lockwood

2007-01-25 10:08:50 UTC

Permalink

On 25/1/07 09:53, in article

Post by Stibbs

Interesting...
I have two Nova-t 500's running from the same arial, now one will pick up
all channels and the other will pick up everything with the one exception of
the ITV channels (ITV1, ITV2, ITV3, Channel 4 etc.)
I can swap the cables around and it makes no difference, the odd thing is
the card I expected to get the trouble (outer part of the arial socket makes
contact with my case) I get all channels the one which I thougt would be best
fails on the ITV front.
I have read about the same issue using the same card on Linux so I am
inclinded to thing its more of an hardware issue than drivers etc.
I am 100% confident its not a signal issue as I had the arial replaced
because of bad signal when I was running two Twinhan DVB-T cards with a
signal booster. I now get 100% quality and 80-90% strength on both inputs.
- Swapping the cards in the PCI slots
- Check IRQ, DMA conflicts
- Check USB bandwidth availability
- Make the outer case of the arial socket make contact with the case
I will get back to you regarding this as I already have one tunner working I
must be able to get both unless there are hardware issues.

Actually it does sound like a reception problem as all the ITV channels will
be on the same multiplex. It is also the case that the ITV multiplex is a
weaker signal than say the BBC multiplex.

If you are using an external (roof) aerial normally you should have no
problem in SW London, but if you are using an indoor aerial you might
(especially one of the mini aerials often included with USB DVB-T tuners.

I am also in SW London and at the moment I do use one of the included mini
aerials but if I carefully position it I can get all the channels. If I move
it too far (just inches) then I do loose some channels.

Also, how are you determining signal quality/strength as Media Center does
not give this information for DVB-T?

stibbs

2007-01-25 10:31:00 UTC

Permalink

I live on high ground on the outskirts of Bristol with direct line of sight
of the Mendip transmitter, the signal strength and quality was configrmed
using BDA tools provided with the Twinhan cards also the professional
installers of the digital arail and high quality cabling and splitter
performed singal testing which also confirmed this.

I feel the fact one card works perfectly with both cables proves the point
that the signal loss is due to poor build quality and not the signal source.

Post by John Lockwood
On 25/1/07 09:53, in article

Post by Stibbs

Interesting...
I have two Nova-t 500's running from the same arial, now one will pick up
all channels and the other will pick up everything with the one exception of
the ITV channels (ITV1, ITV2, ITV3, Channel 4 etc.)
I can swap the cables around and it makes no difference, the odd thing is
the card I expected to get the trouble (outer part of the arial socket makes
contact with my case) I get all channels the one which I thougt would be best
fails on the ITV front.
I have read about the same issue using the same card on Linux so I am
inclinded to thing its more of an hardware issue than drivers etc.
I am 100% confident its not a signal issue as I had the arial replaced
because of bad signal when I was running two Twinhan DVB-T cards with a
signal booster. I now get 100% quality and 80-90% strength on both inputs.
- Swapping the cards in the PCI slots
- Check IRQ, DMA conflicts
- Check USB bandwidth availability
- Make the outer case of the arial socket make contact with the case
I will get back to you regarding this as I already have one tunner working I
must be able to get both unless there are hardware issues.

Actually it does sound like a reception problem as all the ITV channels will
be on the same multiplex. It is also the case that the ITV multiplex is a
weaker signal than say the BBC multiplex.
If you are using an external (roof) aerial normally you should have no
problem in SW London, but if you are using an indoor aerial you might
(especially one of the mini aerials often included with USB DVB-T tuners.
I am also in SW London and at the moment I do use one of the included mini
aerials but if I carefully position it I can get all the channels. If I move
it too far (just inches) then I do loose some channels.
Also, how are you determining signal quality/strength as Media Center does
not give this information for DVB-T?

Judi

2007-11-14 23:59:02 UTC

Permalink

Hi,
I have made loads of calls to Evesham's help desk to try and get my guide
data for ITV, ITV2 and various other channels over a period of 3 years and
had no luck.
The whole PC went back to Evesham and they 'claimed' it worked fine there
but as soon as it came back the guide data was missing from the guide
listings for ITV & ITV2 etc again.
I have also periodically lost channels from Media Center altogether, but in
the past running a few repeated re-configures has always solved it in the end.
This time I stupidly decided to scan for more channels to see if I could
pick up one of the new +1 channels and it is now resolutely refusing to admit
that any more than 28 of the 92 channels exist. This leaves me with BBC1-4
and a few junky ones - ITV, C4, Five ITV2 etc, etc all missing.
I live in West Yorkshire and this happens whichever transmitter I pick.
However if I put my friend's Swindon postcode in it then finds Five but still
not ITV. I think all this excuse blaming the signal is a load of rubbish
because the channels were all there and displaying perfectly 10 minutes
beforehand. Also if I say I'm not using the Guide it finds ALL the channels
without any problem - how would it manage that with no signal??
I have done the Salloway and the Green Button stuff and nothing works. I am
in a low paid job and this PC cost a relative fortune for me and it is so
frustrating that the TV service is so unreliable. I would have expected a big
company like Microsoft to make the effort to put major functionality failures
like this right.
It doesn't look as if anyone will be able to make any new suggestions about
my plight but if you do have any ideas I'll be very, very grateful.
Thanks
Judi

Post by stibbs
I live on high ground on the outskirts of Bristol with direct line of sight
of the Mendip transmitter, the signal strength and quality was configrmed
using BDA tools provided with the Twinhan cards also the professional
installers of the digital arail and high quality cabling and splitter
performed singal testing which also confirmed this.
I feel the fact one card works perfectly with both cables proves the point
that the signal loss is due to poor build quality and not the signal source.

Post by John Lockwood
On 25/1/07 09:53, in article

Post by Stibbs

Interesting...
I have two Nova-t 500's running from the same arial, now one will pick up
all channels and the other will pick up everything with the one exception of
the ITV channels (ITV1, ITV2, ITV3, Channel 4 etc.)
I can swap the cables around and it makes no difference, the odd thing is
the card I expected to get the trouble (outer part of the arial socket makes
contact with my case) I get all channels the one which I thougt would be best
fails on the ITV front.
I have read about the same issue using the same card on Linux so I am
inclinded to thing its more of an hardware issue than drivers etc.
I am 100% confident its not a signal issue as I had the arial replaced
because of bad signal when I was running two Twinhan DVB-T cards with a
signal booster. I now get 100% quality and 80-90% strength on both inputs.
- Swapping the cards in the PCI slots
- Check IRQ, DMA conflicts
- Check USB bandwidth availability
- Make the outer case of the arial socket make contact with the case
I will get back to you regarding this as I already have one tunner working I
must be able to get both unless there are hardware issues.

Actually it does sound like a reception problem as all the ITV channels will
be on the same multiplex. It is also the case that the ITV multiplex is a
weaker signal than say the BBC multiplex.
If you are using an external (roof) aerial normally you should have no
problem in SW London, but if you are using an indoor aerial you might
(especially one of the mini aerials often included with USB DVB-T tuners.
I am also in SW London and at the moment I do use one of the included mini
aerials but if I carefully position it I can get all the channels. If I move
it too far (just inches) then I do loose some channels.
Also, how are you determining signal quality/strength as Media Center does
not give this information for DVB-T?

2007-11-15 14:29:37 UTC

Permalink

Judi, you are not alone.

We have had similar issues with channels vanishing - we pick up the signal
from Emley Moor.

It seems to happen when a new channel is launched or removed and the
numbering of channels changes, my guess is that the company MS uses for EPG
don't co-ordinate their channel changes correctly with the transmitter
people. Either that or MCE has bugs. Either way, I am assuming MS pay the
EPG people handsomely so MS need to sort it out.

I have found that 2-3 days later, we can then get all the channels again,
but currently our channel list has millions of duplicates etc and is a right
mess - MCE doesn't seem to be able to deal with this.

I also paid a LOT for my media center PC and mostly it is a fantastic tool
(and despite being annoyed at MS I wouldn't swap it). I am a computer techie
though and wouldn't recomend one to my mum & dad.

JJ

Post by Judi
Hi,
I have made loads of calls to Evesham's help desk to try and get my guide
data for ITV, ITV2 and various other channels over a period of 3 years and
had no luck.
The whole PC went back to Evesham and they 'claimed' it worked fine there
but as soon as it came back the guide data was missing from the guide
listings for ITV & ITV2 etc again.
I have also periodically lost channels from Media Center altogether, but in
the past running a few repeated re-configures has always solved it in the end.
This time I stupidly decided to scan for more channels to see if I could
pick up one of the new +1 channels and it is now resolutely refusing to admit
that any more than 28 of the 92 channels exist. This leaves me with BBC1-4
and a few junky ones - ITV, C4, Five ITV2 etc, etc all missing.
I live in West Yorkshire and this happens whichever transmitter I pick.
However if I put my friend's Swindon postcode in it then finds Five but still
not ITV. I think all this excuse blaming the signal is a load of rubbish
because the channels were all there and displaying perfectly 10 minutes
beforehand. Also if I say I'm not using the Guide it finds ALL the channels
without any problem - how would it manage that with no signal??
I have done the Salloway and the Green Button stuff and nothing works. I am
in a low paid job and this PC cost a relative fortune for me and it is so
frustrating that the TV service is so unreliable. I would have expected a big
company like Microsoft to make the effort to put major functionality failures
like this right.
It doesn't look as if anyone will be able to make any new suggestions about
my plight but if you do have any ideas I'll be very, very grateful.
Thanks
Judi

Post by John Lockwood
On 25/1/07 09:53, in article

Post by Stibbs

Interesting...
I have two Nova-t 500's running from the same arial, now one will pick up
all channels and the other will pick up everything with the one exception of
the ITV channels (ITV1, ITV2, ITV3, Channel 4 etc.)
I can swap the cables around and it makes no difference, the odd thing is
the card I expected to get the trouble (outer part of the arial socket makes
contact with my case) I get all channels the one which I thougt would be best
fails on the ITV front.
I have read about the same issue using the same card on Linux so I am
inclinded to thing its more of an hardware issue than drivers etc.
I am 100% confident its not a signal issue as I had the arial replaced
because of bad signal when I was running two Twinhan DVB-T cards with a
signal booster. I now get 100% quality and 80-90% strength on both inputs.
- Swapping the cards in the PCI slots
- Check IRQ, DMA conflicts
- Check USB bandwidth availability
- Make the outer case of the arial socket make contact with the case
I will get back to you regarding this as I already have one tunner working I
must be able to get both unless there are hardware issues.

Actually it does sound like a reception problem as all the ITV channels will
be on the same multiplex. It is also the case that the ITV multiplex is a
weaker signal than say the BBC multiplex.
If you are using an external (roof) aerial normally you should have no
problem in SW London, but if you are using an indoor aerial you might
(especially one of the mini aerials often included with USB DVB-T tuners.
I am also in SW London and at the moment I do use one of the included mini
aerials but if I carefully position it I can get all the channels. If I move
it too far (just inches) then I do loose some channels.
Also, how are you determining signal quality/strength as Media Center does
not give this information for DVB-T?

Nigel Barker

2007-11-15 16:38:39 UTC

Permalink

Post by JJ
We have had similar issues with channels vanishing - we pick up the signal
from Emley Moor.
It seems to happen when a new channel is launched or removed and the
numbering of channels changes, my guess is that the company MS uses for EPG
don't co-ordinate their channel changes correctly with the transmitter
people. Either that or MCE has bugs. Either way, I am assuming MS pay the
EPG people handsomely so MS need to sort it out.
I have found that 2-3 days later, we can then get all the channels again,
but currently our channel list has millions of duplicates etc and is a right
mess - MCE doesn't seem to be able to deal with this.
I also paid a LOT for my media center PC and mostly it is a fantastic tool
(and despite being annoyed at MS I wouldn't swap it). I am a computer techie
though and wouldn't recomend one to my mum & dad.

Your problem is caused by a poor signal. It has nothing to do EPG data.

Whenever you change Multiplex (channel group on one frequency also called a MUX) then Media Center
performs so called 'opportunistic scanning'. Which means it checks if any new channels have appeared
or old channels disappeared. If your signal for that MUX is now below the critical level then the
channels will be removed & disappear from the Electronic Programme Guide (EPG). Again your
duplicates are caused by Media Center thinking that it has found new channels.

You need to make sure that you have a good aerial suitable for your digital transmitter & may well
require a signal amplifier (a cheap one from Argos may be all you need). Ensure that you do not
passively split the signal from your aerial downlead between Media Center & any TV or Freeview box.

If that doesn't fix your problem then there can be an issue with Media Center locking on to a
channel from a distant transmitter with a poorer signal in preference to the local transmitter with
a stronger signal. In this case by judicious editing of the registry you can force Media Center to
only scan the MUXes of your desired transmitter. There is a full description of how to do this here
http://thegreenbutton.com/forums/thread/133114.aspx

Vista is much more stable in terms of the DVB-T EPG than MCE 2005 & in particular there is a Hot Fix
that disables Opportunistic Scanning http://support.microsoft.com/default.aspx/kb/938927 You have to
call Microsoft Support to get the fix but it is also available on the 'Net e.g.
http://www.xpmediacentre.com.au/community/vista-media-center-software/21986-important-hotfixes-vista-media-center.html
--

Cheers

Nigel Barker
Live from the sunny Cote d'Azur
MCE MVP

2007-11-19 09:38:01 UTC

Permalink

In my case, don't; think its a problem with a signal from my local
transmitter (have line of sight to Emley Moor and can get a good picture
with no arial at all - don't even need a portable arial) , problem could be
a leaky signal from another transmitter I guess, will look into it. Cheers
for your comments Nigel.

J

Post by Nigel Barker

Your problem is caused by a poor signal. It has nothing to do EPG data.
Whenever you change Multiplex (channel group on one frequency also called
a MUX) then Media Center
performs so called 'opportunistic scanning'. Which means it checks if any
new channels have appeared
or old channels disappeared. If your signal for that MUX is now below the
critical level then the
channels will be removed & disappear from the Electronic Programme Guide (EPG). Again your
duplicates are caused by Media Center thinking that it has found new channels.
You need to make sure that you have a good aerial suitable for your
digital transmitter & may well
require a signal amplifier (a cheap one from Argos may be all you need).
Ensure that you do not
passively split the signal from your aerial downlead between Media Center
& any TV or Freeview box.
If that doesn't fix your problem then there can be an issue with Media
Center locking on to a
channel from a distant transmitter with a poorer signal in preference to
the local transmitter with
a stronger signal. In this case by judicious editing of the registry you
can force Media Center to
only scan the MUXes of your desired transmitter. There is a full
description of how to do this here
http://thegreenbutton.com/forums/thread/133114.aspx
Vista is much more stable in terms of the DVB-T EPG than MCE 2005 & in
particular there is a Hot Fix
that disables Opportunistic Scanning
http://support.microsoft.com/default.aspx/kb/938927 You have to
call Microsoft Support to get the fix but it is also available on the 'Net e.g.
http://www.xpmediacentre.com.au/community/vista-media-center-software/21986-important-hotfixes-vista-media-center.html
--
Cheers
Nigel Barker
Live from the sunny Cote d'Azur
MCE MVP

Nigel Barker

2007-11-15 16:35:58 UTC

Permalink

It's not rubbish about a poor signal. Your signal is marginal & comes & goes. That is why it worked
OK at Evesham as they doubtless have a good signal. Whenever Multiplex (channel group on one
frequency also called a MUX) then Media Center performs so called 'opportunistic scanning'. Which
means it checks if any new channels have appeared or old channels disappeared. If your signal for
that MUX is now below the critical level then the channels will be removed & disappear from the
Electronic Programme Guide (EPG).

You need to make sure that you have a good aerial suitable for your digital transmitter & may well
require a signal amplifier (a cheap one from Argos may be all you need). Ensure that you do not
passively split the signal from your aerial downlead between Media Center & any TV or Freeview box.

If that doesn't fix your problem then there can be an issue with Media Center locking on to a
channel from a distant transmitter with a poorer signal in preference to the local transmitter with
a stronger signal. In this case by judicious editing of the registry you can force Media Center to
only scan the MUXes of your desired transmitter. There is a full description of how to do this here
http://thegreenbutton.com/forums/thread/133114.aspx

Vista is much more stable in terms of the DVB-T EPG than MCE 2005 & in particular there is a Hot Fix
that disables Opportunistic Scanning http://support.microsoft.com/default.aspx/kb/938927 You have to
call Microsoft Support to get the fix but it is also available on the 'Net e.g.
http://www.xpmediacentre.com.au/community/vista-media-center-software/21986-important-hotfixes-vista-media-center.html
--

Cheers

Nigel Barker
Live from the sunny Cote d'Azur
MCE MVP