Band pass filters -- what am I missing?

Brian Gregory [UK] wrote:
"Bill Wright" wrote in message
...
Brian Gregory [UK] wrote:
"Bill Wright" wrote in message
...
Mark Carver wrote:
Welcome to the world of high power overlapping DTT.
They give us all this bull**** about spectrum being scarce, but what
could be more profligate than transmitting DTT on ten times the
necessary power?

I don't think we should have to stay forever on low power just because the
current generation of receivers have poorly designed firmware that can't
even work out the best frequency to use for a particular multiplex.

That's not really the point, which is in fact that over-powerful
transmissions waste bandwidth.

Bill

On Mon, 29 Aug 2011 19:53:12 +0100, Bob Latham
wrote:

In article ,
Scott wrote:
On Sat, 27 Aug 2011 20:47:23 +0100, Bob Latham
wrote:

In article ,
J G Miller wrote:
On Saturday, August 27th, 2011 at 20:02:55h +0100, Bob Latham asked:

But what about devices that do not have a manual tune facility?

Simple solution -- do not buy them.

I have a Sony DVD/HDD recorder purchased in 2005 it doesn't have a
manual tune and I don't have a TARDIS to reverse the purchase decision.
At the time a manual tune function wasn't in the top 20 items on the
check list.

My Father's TV purchased last christmas (Sony KDL-32EX503) has a manual
tune but it did my head in trying to use it. It appears you can start a
scan at any channel and they decide to either go up or down channels
from that point, most odd, couldn't understand it.

I have a KDL-37EX503 and the process was dead easy.

Perhaps you can enlighten me then.

1) My first problem was that doing an auto scan with the aerial
disconnected didn't clear the memory. How did you clear the memory
prior
to a manual tune.

You probably need to do a "factory initialisation" automatic tune with
the antenna unplugged. There might be an option to clear the channel
list[1] hidden away in the menu options. Being a Sony gadget, it's
unlikely to be a very obvious feature.


2) On the manual tune, I can set the start channel then it wants to know
if you wish to scan up or down from that point. Dir? I don't wish to
do
either.

That, if I may say so, is rather a strange response to what is a very
neat (if rather pragmatic) solution to the problem of mis-allocating LCNs
to undesired muxen.

Admittedly, use of this feature does require that the user has knowledge
of at least one important fact regarding the transmitter they wish to use
as their primary signal source. The required fact is simply which is the
lowest or highest frequency channel of the group allocated to the
transmitter. Once you know either you can choose the starting channel and
select the scan direction which will cover the channels from that
transmitter before it finds any other transmitters. Presumably, when the
scan reaches the end of the band, it will wrap around to the opposite end
and carry on scanning till it has scanned all the channels.

The point of this option is that it avoids the need to unplug the antenna
in order to stop unwanted channels at the low end of the band from being
identified and given LCNs you wish to be reserved to muxes higher up the
band whenever a retune is required in response to transmitter changes.

3) After you've scanned a channel it asks which services you wish to
accept. I don't understand, I want then all from that mux, why would
you want anything else?

Another useful option, but I could imagine, since it is a Sony product,
that it's not obvious how you're meant to make your selection.


4) How do you accept items in [3]. Very poor interface IMHO. Certainly
defeated me.

Well, that's par for the course as far as Sony kit goes. There does seem
to be an ambition at Sony to (eventually one day real soon now) impose a
de-facto standard upon the world and finally join the ranks of Microsoft
and Apple. Unfortunately, this ambition seems to encompass user interfaces.

[1] In view of the existence of the manual tune option, one would
logically expect such an option to be available if not already built into
the manual tune option itself.

--
Regards JB Good

Are you aware that Bromsgrove, Lark Stoke, and The Wrekin are now an
SFN?


I asked the same question of someone in April
http://newsgroups.derkeiler.com/Arch.../msg00588.html

(Sorry about the advert-ridden archive site)

--
Graham.

%Profound_observation%

Bob Latham wrote:

I have a KDL-37EX503 and the process was dead easy.

Perhaps you can enlighten me then.

I have the same chassis set. Never tried a manual tune, however be aware of
the following.

1: I'm led to understand that the TV will place the *strongest* transmissions
it finds, on the primary LCNs. I have no way to prove this at present, because
currently my strongest DTT muxes are the lowest in the band. Perhaps someone
else can try it ?

2: You can edit, shuffle, and delete the EPG/LCN list to your heart's content.
This is the case, I've moved BBC News from 80 to 8, and deleted all the
shopping and p0rn crap.

The combination of those two features should allow you (albeit rather
tediously perhaps) to end up with the correct channels in the right place ?

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

www.paras.org.uk

On 30/08/2011 08:19, Bob Latham wrote:
In [email protected],
Johny B wrote:

3) After you've scanned a channel it asks which services you wish to
accept. I don't understand, I want then all from that mux, why
would you want anything else?

Another useful option, but I could imagine, since it is a Sony
product, that it's not obvious how you're meant to make your selection.

Why on earth would not wish to take any services offered on a mux?

Two scenarios.

1: You may wish to add an additional alternative BBC 1 region, but you
wouldn't want to add BBC 2,3, 4 etc from that mux as well ?

2: You may want to remove any crap channels from a particular mux,
shopping, p0rn, encrypted etc ?




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

www.paras.org.uk

Bob Latham wrote:


2) On the manual tune, I can set the start channel then it wants to know
if you wish to scan up or down from that point. Dir? I don't wish to do
either.

I've had a play. You enter the UHF channel allocation required, either
by scrolling to it, or by punching it in from the RC keyboard.

Press the centre tit to confirm.

You then hit 'Scan Up'

As long as it finds a valid signal on that allocation, it gives you a
list of the services on that mux, for you to choose which to store.

If you should select a UHF allocation that is empty, it scans up the
band until it does find a valid mux, then stops at that mux, and lists
its services.

So to all intents and purposes it is possible to scan on a single UHF
allocation, and nothing more.

On 30/08/2011 15:24, Bob Latham wrote:
In ,
Mark wrote:

So to all intents and purposes it is possible to scan on a single UHF
allocation, and nothing more.

Thanks Mark, very good of you.

I've just now got to work out how to clear the memory without a factory
reset and how to add the services it offers me.

Yes, that could be a challenge !

If you can't, what you could do, is to initiate a full auto scan, let it
find the first mux (hopefully not Mux A coz that's full of stuff !) and
then yank out the aerial lead. That should just store only the handful
of channels on that mux. You can then delete them all using the
'Programme Edit' menu, and then run manual mux by mux scans ?


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

www.paras.org.uk

I was wondering if one solution to the multiple transmissions problem
might be for boxes to simply put every version of (say) ITV1 they find
at preset 3. If you pressed the up button or down button the box would
move up or down to the next ITV1 version, before progressing tp preset 2
or 4. But if you keyed in the number direct (3 or 03) you would get
either the lowest frequency version or the best signal version (it
wouldn't matter which). This would be the first preset 3, adjacent on
the up-down buttons to preset 2. There would then be a 'delete channel'
button (not a menu item) which would simply require confirmation
('Delete this channel?'). We could then say to customers, "Look, you've
got several copies of each channel. If any of them break up, or they
give you the wrong local news, just delete them." Recording boxes could
simply ignore all except the first version for recording purposes.

Bill

On 28 Aug,
charles wrote:

Why didn't they give each individual TX its own ID and allow the user to
tell the box to scan for a specified ID?

Not so easy when the 'transmitter' is a transposer.

They effectively manage it with VHF radio RDS. A channel table could be
broadcast from the main station and a choice made (either by postcode or
transmitter) at teh receiver.

--
BD
Change lycos to yahoo to reply

"Bill Wright" wrote in message
...
Brian Gregory [UK] wrote:
"Bill Wright" wrote in message
...
Brian Gregory [UK] wrote:
"Bill Wright" wrote in message
...
Mark Carver wrote:
Welcome to the world of high power overlapping DTT.
They give us all this bull**** about spectrum being scarce, but what
could be more profligate than transmitting DTT on ten times the
necessary power?

I don't think we should have to stay forever on low power just because
the current generation of receivers have poorly designed firmware that
can't even work out the best frequency to use for a particular multiplex.

That's not really the point, which is in fact that over-powerful
transmissions waste bandwidth.

Only from the point of view of somebody trying to use lower power on the
same channel.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.