Most DTTV set-top boxes, and I presume integrated TVs, know about and use 
the logical channel numbers - so that, for example, BBC News 24 is on 
channel 80 (currently).

However, I have seen one STB, and was most surprised to find the same in a 
(cheap) IDTV (fortunately not one I'd bought!), which allocate channel 
numbers in the order they find the stations (I think separately for radio 
and TV) - with the result that they go up to about 29. As far as I could 
tell by fiddling (and even reading the manual), all you could do was switch 
over any two (in fact I think on the IDTV it was worse than that, something 
like declare any one signal as number X, and all those between that and 
where it had been shuffled along by one).

Two questions:

1. Are they really like this, or can the proper LCNs be allocated, and I 
just haven't found out how; and,
2. If they really are this bad, is there a way of finding out _before_ 
buying?
-- 
J. P. Gilliver                  |  Tel. +44 1634 203298

Essex home for sale, £59,950: see http://www.soft255.demon.co.uk/home/

J. P. Gilliver wrote:
> Most DTTV set-top boxes, and I presume integrated TVs, know about and use 
> the logical channel numbers - so that, for example, BBC News 24 is on 
> channel 80 (currently).
> 
> However, I have seen one STB, and was most surprised to find the same in a 
> (cheap) IDTV (fortunately not one I'd bought!), which allocate channel 
> numbers in the order they find the stations (I think separately for radio 
> and TV) - with the result that they go up to about 29. As far as I could 
> tell by fiddling (and even reading the manual), all you could do was switch 
> over any two (in fact I think on the IDTV it was worse than that, something 
> like declare any one signal as number X, and all those between that and 
> where it had been shuffled along by one).
> 
> Two questions:
> 
> 1. Are they really like this, or can the proper LCNs be allocated, and I 
> just haven't found out how; and,
> 2. If they really are this bad, is there a way of finding out _before_ 
> buying?

I remember a very early problem we had with the original Sony idTV.
It allocated a channel as it found it in the PAT (Programme Association 
Table).  So button 1 could be BBC1, but it stored what the PMT Programme 
Mapping Table) in position 1 of the PAT said.

Trouble was that the order of PMTs in the PAT changed.  So BBC1 might 
well be button 1 on the remote today, but if the regional multiplexer or 
even SIPSI changed over it could be, say, N24 tomorrow!

I think we ordered the PATs to be the same to help Sony out!

Richard

On Jan 22, 11:45 am, Dickie mint
 wrote:
> J. P. Gilliver wrote:
>
> Trouble was that the order of PMTs in the PAT changed.  So BBC1 might
> well be button 1 on the remote today, but if the regional multiplexer or
> even SIPSI changed over it could be, say, N24 tomorrow!
>
> I think we ordered the PATs to be the same to help Sony out!

Sony always screw things up. Their incompetence is also the reason why
we're "not allowed" to have Line 23 signalling on analogue...

On Jan 22, 2:15 pm, jamie_...@excite.com wrote:
>
>  wrote:

> > I think we ordered the PATs to be the same to help Sony out!
>
> Sony always screw things up. Their incompetence is also the reason why
> we're "not allowed" to have Line 23 signalling on analogue...

Well not quite true, C4 use it (as a left over from their PAL+
transmissions). However because some early Sony sets interpret the L23
WSS for 4:3 as an instruction to enter 'Smart Non Linear Stretch'
mode, when 4:3 working is required (which is most of the time), the
L23 WSS must NOT be present. Most w/s sets, Sony or otherwise, revert
to 4:3 in the absence of L23 WSS.

On Jan 22, 3:10 pm, Mark Carver  wrote:
> On Jan 22, 2:15 pm, jamie_...@excite.com wrote:
>
> Well not quite true, C4 use it (as a left over from their PAL+
> transmissions). However because some early Sony sets interpret the L23
> WSS for 4:3 as an instruction to enter 'Smart Non Linear Stretch'
> mode, when 4:3 working is required (which is most of the time), the
> L23 WSS must NOT be present. Most w/s sets, Sony or otherwise, revert
> to 4:3 in the absence of L23 WSS.

But most progamming on analogue is in blurry old 14:9, not 4:3.
C4 only use it to signal 16:9 letterbox - their L23 signal disappears
completely when material is being shown in 14:9 or 4:3.

"J. P. Gilliver"  wrote in message 
news:47953f82$1_1@glkas0286.greenlnk.net...
> Most DTTV set-top boxes, and I presume integrated TVs, know about and use 
> the logical channel numbers - so that, for example, BBC News 24 is on 
> channel 80 (currently).
>
> However, I have seen one STB, and was most surprised to find the same in a 
> (cheap) IDTV (fortunately not one I'd bought!), which allocate channel 
> numbers in the order they find the stations (I think separately for radio 
> and TV) - with the result that they go up to about 29. As far as I could 
> tell by fiddling (and even reading the manual), all you could do was 
> switch over any two (in fact I think on the IDTV it was worse than that, 
> something like declare any one signal as number X, and all those between 
> that and where it had been shuffled along by one).

I have encountered two such. I explained to the customer in both cases that 
the item was a bag a shite and left them to figure the channels out.

Bill

jamie_p84@excite.com wrote:
> On Jan 22, 3:10 pm, Mark Carver  wrote:
>> On Jan 22, 2:15 pm, jamie_...@excite.com wrote:
>>
>> Well not quite true, C4 use it (as a left over from their PAL+
>> transmissions). However because some early Sony sets interpret the L23
>> WSS for 4:3 as an instruction to enter 'Smart Non Linear Stretch'
>> mode, when 4:3 working is required (which is most of the time), the
>> L23 WSS must NOT be present. Most w/s sets, Sony or otherwise, revert
>> to 4:3 in the absence of L23 WSS.
> 
> But most progamming on analogue is in blurry old 14:9, not 4:3.
> C4 only use it to signal 16:9 letterbox - their L23 signal disappears
> completely when material is being shown in 14:9 or 4:3.

I should take that up with C4 then, it's got nothing to do with Sony's WSS 
problem.

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