Mendip Post DSO update
Mark Carver
Ofcom have just updated the Mendip (HTV West) channel allocation plan
for DSO.
http://www.ofcom.org.uk/tv/ifi/tech/dsodetails/Westv3.0.pdf
--
Mark
Please replace invalid and invalid with gmx and net to reply.
Andr� Coutanche
> Ofcom have just updated the Mendip (HTV West) channel allocation
> plan for DSO.
>
> http://www.ofcom.org.uk/tv/ifi/tech/dsodetails/Westv3.0.pdf
Thanks, Mark, both on my behalf and that of some friends in deepest, darkest
Dorset, whom I expect I will have to brief.
What's with these + channels? For analogue, I would have assumed that it's a
slight frequency offset to reduce CCI with some other tx, but how does that
apply on digital? And do all tuners - specifically the ones in my Topfield
5800! - cope with these offsets OK?
For my tx (Ilchester Crescent) it says that between the first and second
stages of DSO, the SDN mux 'will operate on channel 42 (at 40W ERP)'.
Since the final allocation is shown as channel 42+ at 100W, I'm not clear
whether they mean that the frequency AND power will be tweaked between
DSO1 and DSO2, or just the power. Hopefully it won't matter if I just keep
rescanning ...
Andr� Coutanche
Mark Carver
> Mark Carver wrote:
>> Ofcom have just updated the Mendip (HTV West) channel allocation
>> plan for DSO.
>>
>> http://www.ofcom.org.uk/tv/ifi/tech/dsodetails/Westv3.0.pdf
>
> Thanks, Mark, both on my behalf and that of some friends in deepest, darkest
> Dorset, whom I expect I will have to brief.
>
> What's with these + channels? For analogue, I would have assumed that it's a
> slight frequency offset to reduce CCI with some other tx, but how does that
> apply on digital? And do all tuners - specifically the ones in my Topfield
> 5800! - cope with these offsets OK?
The offsets are indeed there to reduce CCI effects. Only one receiver is
affected by offset operation, some early s/w versions of the Vestel T810
PVRs
<http://www.digitaluk.co.uk/__data/assets/pdf_file/0017/41291/T810_Note_2.pdf>
>
> For my tx (Ilchester Crescent) it says that between the first and second
> stages of DSO, the SDN mux 'will operate on channel 42 (at 40W ERP)'.
> Since the final allocation is shown as channel 42+ at 100W, I'm not clear
> whether they mean that the frequency AND power will be tweaked between
> DSO1 and DSO2, or just the power. Hopefully it won't matter if I just keep
> rescanning ...
That's two of us that are confused ! I don't understand the logic
either, as you say, best policy is to keep rescanning !!
jamie powell
"Mark Carver" <mark....@invalid.invalid> wrote in message
news:7tdjhj...@mid.individual.net...
> The offsets are indeed there to reduce CCI effects. Only one receiver is
> affected by offset operation, some early s/w versions of the Vestel T810 PVRs
>
> <http://www.digitaluk.co.uk/__data/assets/pdf_file/0017/41291/T810_Note_2.pdf>
>
Freecom's USB TV stick is affected too, and there's currently no fix available
for it.
Java Jive
internal only version. Also STV North is now on v2.
BTW, I've now has a reply to most of my queries to Ofcom. Some
interesting points have come out of them ...
1) Naming policy is to adhere to names used by Digital UK, even
though some do not agree with Ordnance Survey spelling, etc (that is
even where DUK are actually wrong).
There are 17 such cases that I have found, the worst being Knockmore
(correct), which DUK call Knock More (incorrect), and where the latter
is actually the name of an entirely different place 100 odd miles away
in Fife.
Here are the others:
Ofcom Ordnance Survey
Cwmtwrch Cwm Twrch
Cwm-gors Cwmgors
Moel-y-Parc Moel Y Parc
Tonpentre Ton Pentre
Ashford-in-Water Ashford In The Water
Bleach Green Bleachgreen
Callender Callander
Kilmalcom Kilmacolm
Kirkudbright Kirkcudbright
Olivers Mount Oliver's Mount
Penicuick Penicuik
Ross On Wye Ross-on-Wye
Sedburgh Sedbergh
Stanraer Stranraer
Sutton in Craven Sutton-In-Craven
Walton Le Dale Walton-Le-Dale
2) Have to ask BBC about apparently anomalous date for DVB-T2 (just 1
month after DSO).
3) Missing end date for Torosay DSO is 27/10/2010
4) Lochgoilhead & Lochgoilhead AD: "The NGRs for both transmitter
sites are correct. The mast marked on OS maps at NS196976 is likely to
be Lochgoilhead AD�s remote receiving site, which is connected by
cable to the transmitter site itself. Remote receive sites are usually
needed by active deflectors in order to achieve sufficient isolation
between the transmit and receive antennas, and the geography of the
area in this case also requires a remote receive site. Lochgoilhead
AD�s transmit antenna height is 312m AOD."
5) Widely differing NGRs for Black Hill: "Black Hill mast has been
rebuilt for DSO, at NS831645" (the previous NGR was correct for the
original mast).
6) Missing Data
Link sites not intended for domestic reception were omitted from
Analogue data but are now included in DSO data for completeness.
Missing Aerial Heights*:
Chaigley 194m AOD
Skelmersdale 168m AOD
Jurby (IoM) 62m AOD
Ramsey (IoM) 136m AOD
Missing Aerial Group:
Crosthwaite C/D
Missing Aerial Polarity:
Hazler Hill V
Norden V
Ridge Hill relays missing aerial polarity on website are all V (except
Garth Hill HP):
Andoversford
Eardiston
Ewyas Harold
Garth Hill VP
Hereford
Hope Under Dinmore
Kington
Knucklas
Ludlow
New Radnor
Oakeley Mynd
Peterchurch
Presteigne
Ross-On-Wye
St Briavels
Upper Soudley
Incorrect or missing Analogue ERPs:
Bowmore HP 60W
Bowmore VP 50W
Scoval HP 660W
S Brent HP 0.5W
* I also now have from elsewhere the aerial height of Beddgelert Link,
193m AOD.
On Tue, 09 Feb 2010 13:11:19 +0000, Mark Carver
<mark....@invalid.invalid> wrote:
>
> Ofcom have just updated the Mendip (HTV West) channel allocation plan
> for DSO.
>
> http://www.ofcom.org.uk/tv/ifi/tech/dsodetails/Westv3.0.pdf
--
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Andr� Coutanche
> On 09/02/2010 16:28, Andr� Coutanche wrote:
<snip>
>>Hopefully it won't matter if I just keep rescanning ...
>
> That's two of us that are confused ! I don't understand the logic
> either, as you say, best policy is to keep rescanning !!
:-) Thanks, Mark. At least the ERP will be going up and - fingers crossed -
the current occasional break-up will disappear.
Andr� Coutanche
Andy Wade
> The offsets are indeed there to reduce CCI effects.
No (at least not AFAIK). DTT offsets (±166.667 kHz) are used to ease
filtering requirements at the transmitters.
--
Andy
Mark Carver
The statement in the Digital UK link..
"The use of a offset is designed to remove interference with other
channels."
..is a bit ambiguous then !
Terry Casey
> On 10/02/2010 09:44, Andy Wade wrote:
>> Mark Carver wrote:
>>
>>> The offsets are indeed there to reduce CCI effects.
>>
>> No (at least not AFAIK). DTT offsets (±166.667 kHz) are used to ease
>> filtering requirements at the transmitters.
>
> The statement in the Digital UK link..
>
> "The use of a offset is designed to remove interference with other
> channels."
>
>
>
I think this came up in another thread recently and related to
*adjacent* channels where a DTT channel is adjacent to an analogue one.
In this case, however, there will be no analogue signals!
However, looking through the lists, these offsets are confined to 21+,
41+ & 62- (an exception is 42+ at Bristol Ilchester Crescent which will
be necessary because 41+ is also used at the same site).
None of these channels is used in this plan without an offset so I would
guess that these offsets are used to prevent any possibility of
radiating anything beyond the band edges: 21 is the first channel in
Band IV, 41 will be the first channel in Band V and 62 the last.
There is no allocation for channel 30 in the list, otherwise we'd have
the full set!
So, to paraphrase the original statement, perhaps it should read "The
use of an offset is designed to prevent interference to users of
adjacent spectrum."
--
Terry
Terry Casey
>
> For my tx (Ilchester Crescent) it says that between the first and second
> stages of DSO, the SDN mux 'will operate on channel 42 (at 40W ERP)'.
> Since the final allocation is shown as channel 42+ at 100W, I'm not clear
> whether they mean that the frequency AND power will be tweaked between
> DSO1 and DSO2, or just the power. Hopefully it won't matter if I just keep
> rescanning ...
>
Footnotes e & f say:
e Mendip COM multiplexes will temporarily operate on channels 62+ for
SDN, 56+ for Arqiva A, and 59+ for Arqiva B (all at 10kW ERP) until
Autumn 2011. Final DSO channels will then be adopted, though ERP levels
will remain limited until early 2012.
f Bristol Ilchester Crescent: between the first and second stages of
digital switchover, the SDN multiplex will operate on channel 42 (at 40W
ERP).
Assuming that there is consistency here, it certainly looks as if there
will be no offset until after the second stage (when 42+ will be
necessary because of the adjacent 41+).
--
Terry
Mark Carver
>
> f: Bristol Ilchester Crescent: between the first and second stages of
> digital switchover, the SDN multiplex will operate on channel 42 (at 40W
> ERP).
And that must because Briston Kings Keston ITV uses Ch 42 for ITV
analogue, so Bristol IC can't use full whack for the SDN mux until DSO
stage 2.
>
> Assuming that there is consistency here, it certainly looks as if there
> will be no offset until after the second stage (when 42+ will be
> necessary because of the adjacent 41+).
Seems a reasonable assumption. Good game in'it ?
Ian
<k.t...@example.invalid> writes
--
Ian
Terry Casey
> In message <6Bwcn.187499$6V1....@newsfe30.ams2>, Terry Casey
> <k.t...@example.invalid> writes
>>
>> 41+ & 62- (an exception is 42+ at Bristol Ilchester Crescent which
>> will be necessary because 41+ is also used at the same site).
>>
>> None of these channels is used in this plan without an offset so I
>> would guess that these offsets are used to prevent any possibility of
>> radiating anything beyond the band edges: 21 is the first channel in
>> Band IV, 41 will be the first channel in Band V and 62 the last.
>>
>> There is no allocation for channel 30 in the list, otherwise we'd have
>> the full set!
>>
But that doesn't help! The offset will not be required until channel 31
is sold off. There is no channel 30 in the main (long-term) list.
--
Terry
Graham.
"Mark Carver" <mark....@invalid.invalid> wrote in message news:7tfk7f...@mid.individual.net...
> On 10/02/2010 11:24, Terry Casey wrote:
>>
>> f: Bristol Ilchester Crescent: between the first and second stages of
>> digital switchover, the SDN multiplex will operate on channel 42 (at 40W
>> ERP).
>
> And that must because Briston Kings Keston ITV uses Ch 42 for ITV analogue, so Bristol IC can't use full whack for the SDN mux
> until DSO stage 2.
>
>>
>> Assuming that there is consistency here, it certainly looks as if there
>> will be no offset until after the second stage (when 42+ will be
>> necessary because of the adjacent 41+).
>
> Seems a reasonable assumption. Good game in'it ?
We're discussing Ilchester Crescent, not Mornington Crescent.
--
Graham.
%Profound_observation%
Java Jive
On Wed, 10 Feb 2010 05:20:01 +0000, Java Jive <ja...@evij.com.invalid>
wrote:
>
> 2) Have to ask BBC about apparently anomalous date for DVB-T2 (just 1
> month after DSO).
Mark Carver
>> 2) Have to ask BBC about apparently anomalous date for DVB-T2 (just 1
>> month after DSO).
> For Knockmore, that is ...
Knockmore is the penultimate main station in the 'STV North' aka Grampian TV
region to have DSO. Rosemarkie is the last, a month later. So my guess is
DVB-T2 won't get enabled until Rosemarkie's DSO.
It's strange, however remember that the DVB-T2 capable kit has/is being
retrofitted, because Ofcom decided to adopt it after Arqiva had arranged and
ordered kit for the early-mid DSO sites. I suspect some advance work has
already been carried out in Scotland installing DVB-T1 kit at some sites, and
Arqiva need to revisit these sites to upgrade to DVB-T2, while still
maintaining the original timescale to complete DSO nationally by the end of 2012 ?
Just guessing though.
--
Mark
Please replace invalid and invalid with gmx and net to reply.
Java Jive
In this paragraph I accidentally swapped the names around - the
correct spelling for the transmitter is Knock More, which is in Moray,
but DUK and Ofcom refer to it as Knockmore, of which there are two,
one in Fife, the other in Dumfries & Galloway.
Apologies for any additional confusion caused.
On Wed, 10 Feb 2010 05:20:01 +0000, Java Jive <ja...@evij.com.invalid>
wrote:
>
> There are 17 such cases that I have found, the worst being Knockmore
> (correct), which DUK call Knock More (incorrect), and where the latter
> is actually the name of an entirely different place 100 odd miles away
> in Fife.