mux ID
 

I always assumed that a DTT receiver tuned-in to one transmitter
wouldn't work on another. However we brought a box back here that had
been tuned to ch24 Sandy (nothing else had been tuned in; it's a long
story) and it sprung to life here on the bench on the weak ch24
Crosspool signal from our Emley Moor aerial. The ID came up as
'Cambridgeshire'(or something).

Bill

mux ID
 

Undocumented feature then, ie the testers never tested if that id was being
looked at as a way to detect it needed a retune.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Bill Wright" wrote in message
...
I always assumed that a DTT receiver tuned-in to one transmitter wouldn't
work on another. However we brought a box back here that had been tuned to
ch24 Sandy (nothing else had been tuned in; it's a long story) and it
sprung to life here on the bench on the weak ch24 Crosspool signal from our
Emley Moor aerial. The ID came up as 'Cambridgeshire'(or something).

Bill

mux ID
 

In message , Bill Wright
writes
I always assumed that a DTT receiver tuned-in to one transmitter
wouldn't work on another.

Why? Where I used to live my old Panasonic picked up from Crystal
Palace and Bluebell Hill with almost the same signal strength and
quality. Duplicate channels appeared in the 800 series, but there
didn't seem to be any logic as to which went into the main channel
number sequence other than all channels on the same mux were in one
group or the other.
--
Kennedy

mux ID
 

Kennedy McEwen wrote:
In message , Bill Wright
writes
I always assumed that a DTT receiver tuned-in to one transmitter
wouldn't work on another.

Why? Where I used to live my old Panasonic picked up from Crystal
Palace and Bluebell Hill with almost the same signal strength and
quality. Duplicate channels appeared in the 800 series, but there
didn't seem to be any logic as to which went into the main channel
number sequence other than all channels on the same mux were in one
group or the other.
What I meant was that having tuned a receiver to the chxx signal from
tx(1) I didn't expect it to decode a chxx signal from tx(2).

Bill

mux ID
 

On 02/07/2013 19:48, Bill Wright wrote:
Kennedy McEwen wrote:
In message , Bill Wright
writes
I always assumed that a DTT receiver tuned-in to one transmitter
wouldn't work on another.

Why? Where I used to live my old Panasonic picked up from Crystal
Palace and Bluebell Hill with almost the same signal strength and
quality. Duplicate channels appeared in the 800 series, but there
didn't seem to be any logic as to which went into the main channel
number sequence other than all channels on the same mux were in one
group or the other.
What I meant was that having tuned a receiver to the chxx signal from
tx(1) I didn't expect it to decode a chxx signal from tx(2).

Why on earth not? The decoder just decodes what it's presented with
from the radio tuner.
--
Phil Cook

mux ID
 

In article ,
Phil Cook wrote:

What I meant was that having tuned a receiver to the chxx signal from
tx(1) I didn't expect it to decode a chxx signal from tx(2).

Why on earth not? The decoder just decodes what it's presented with
from the radio tuner.

Evidently. But it might not do that - it might check that whatever
the relevant ID is hasn't changed since it was tuned. Probably the
most useful thing for it to do is accept it but put up a warning
notice - if you've moved house you probably want to retune even if
there's a multiplex on one of the ones you used before.

-- Richard

mux ID
 

Richard Tobin wrote:
In article ,
Phil Cook wrote:

What I meant was that having tuned a receiver to the chxx signal from
tx(1) I didn't expect it to decode a chxx signal from tx(2).

Why on earth not? The decoder just decodes what it's presented with
from the radio tuner.

Evidently. But it might not do that - it might check that whatever
the relevant ID is hasn't changed since it was tuned. Probably the
most useful thing for it to do is accept it but put up a warning
notice - if you've moved house you probably want to retune even if
there's a multiplex on one of the ones you used before.

In the example we experienced it was, by coincidence, the same mux both
times. I wonder what would have happened if it hadn't been?

Bill

mux ID
 

In article , Bill Wright
wrote:


Evidently. But it might not do that - it might check that whatever
the relevant ID is hasn't changed since it was tuned. Probably the
most useful thing for it to do is accept it but put up a warning
notice - if you've moved house you probably want to retune even if
there's a multiplex on one of the ones you used before.

In the example we experienced it was, by coincidence, the same mux both
times. I wonder what would have happened if it hadn't been?

The USB DTTV 'dongle' and software I use seem to function on the basis of
having a look-up table where each 'station' has an assigned name, mux
frequency, and packet ID values. So if all these match I suspect it won't
care about the actual TX ID. When given a station name it will look up the
frequency and packet IDs, and read them from the stream.

No idea if any particular set-top or TV tuners work differently. But it
seems like reasonably logical method.

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
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Audio Misc http://www.audiomisc.co.uk/index.html

mux ID
 

On Tue, 02 Jul 2013 19:48:11 +0100, Bill Wright
wrote:

Kennedy McEwen wrote:
In message , Bill Wright
writes
I always assumed that a DTT receiver tuned-in to one transmitter
wouldn't work on another.

Why? Where I used to live my old Panasonic picked up from Crystal
Palace and Bluebell Hill with almost the same signal strength and
quality. Duplicate channels appeared in the 800 series, but there
didn't seem to be any logic as to which went into the main channel
number sequence other than all channels on the same mux were in one
group or the other.
What I meant was that having tuned a receiver to the chxx signal from
tx(1) I didn't expect it to decode a chxx signal from tx(2).


I can't help but there's an expert who frequents this group who might
be able to help - can't remember his name, Will or something from up
North.

--
AnthonyL

mux ID
 

....snip...
What I meant was that having tuned a receiver to the chxx signal from
tx(1) I didn't expect it to decode a chxx signal from tx(2).
+++++++++++++++
Assuming that "channel" maps to the same "internal ID" then I don't see a
reason why it shouldn't.

Consider the TV in our canteen - BBC1HD is at "channel" 40-something because
it hasn't been retuned in ages, but BBC1HD does work. But the transmitted
signal has clearly changed because from the same transmitter, I get BBC1HD
on "channel" 101 at home. However it seems that the TVs store "BBC1HD is
channel 40/101" when tuned, and ignore any additional or changed information
which might arrive later.

So when you select a "channel" on the telly, this must mean is that:

"Channel 101" must map to a frequency (i.e. ch24 in your case) and some MUX
component identifier (let's say 9) which means some TV station such as
"BBC1HD".

Now as we know, modern sets can also detect "I'm in the Yorkshire region"
and display this when you tune, but would they need to store it? No,
because the mapping from "channel" to "ch24, MUX cid 9" doesn't depend on
whether the signal came from a Yorkshire transmitter, or Cambridge or
Crystal Palace.

The only reason you might need this were if the mapping to ch24/cid 9 might
exist twice but you can't be receiving ch24 from two transmitters at once
(or at least not in a manner that the TV could handle) so there is no need
to distinguish such an event.

So, providing "ch24, MUX cid 9" exists from both the previous, and your
current, transmitter, and providing you have a "channel" which maps to this,
moving the box won't matter.

Paul DS.