Band pass filters -- what am I missing?

In article , Bill Wright
wrote:
Jim Lesurf wrote:
In article , Bill Wright
wrote:
Here's a list of bandpass filters.

http://dl.dropbox.com/u/11023364/bandpass%20filters.doc

Has anyone (independent of the makers) done measurements on them and
put the results onto the web?

Slainte,

Jim

I checked out most of the ones listed merely to ensure that they did
roughly what they're supposed to, which they all did. There were no big
surprises regarding through loss, out-of-desired-band attenuation, etc.
Of course this wasn't a rigorous test; just a 'fit for purpose' test.

OK, could you perhaps sometime add those figures to the above document? It
would save those interested from having to re-chase the figures.

Slainte,

Jim

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Peter Duncanson wrote:


I hope you realise that my suggestion was not particularly serious.

That's my fault for posting after my normal bed time !

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

www.paras.org.uk

On Mon, 29 Aug 2011 10:02:14 +0100, Mark Carver
wrote:

Peter Duncanson wrote:


I hope you realise that my suggestion was not particularly serious.

That's my fault for posting after my normal bed time !

sympathetic smile

My sci-fi style imaginings might become true in a future generation of
technology unless, of course, terrestrial TV transmission has been
completely replaced by internet distribution of programmes.

--
Peter Duncanson
(in uk.tech.digital-tv)

"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?


There are plenty of places where it will be very useful to have some more
power to give a bit more immunity from unsuppressed motor bikes, weather
bringing in French DTV signals etc.

Yes regarding the motorbikes, but actually they have overdone it and the
problems caused outweigh the benefits.

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.

No regarding French signals, because that policy would simply lead to
escalation. If you want to avoid interference from abroad the way to do it
has an international agreement to restrict power towards other countries,
not have everyone cranking the power up.

As I understand it the French have already cranked the power up, we, on our
south coast, just need to catch up.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.

On Sun, 28 Aug 2011 19:30:22 +0100, "Brian Gregory [UK]"
wrote:

"J G Miller" wrote in message
...
On Sun, 28 Aug 2011 16:13:58 +0000, Richard Tobin wrote:

There must be numerous ways that lists of channels for each transmitter
could be provided in a compatible way, for example over MHEG.

Yes but how does the user get the information via MHEG before the
first autoscan on a brand new box?

The box just needs to be able to get the list of channels on the same
transmitter from every channel is finds a signal on.

The box could scan all channels and work out which channels formed sets from
the same transmitter and announce that it had received more than one
transmitter (and tell you the channels and aerial group of each in case you
understood that) and let you choose which to use.

Probably require too much memory and programming to make the box "cost
effective". be a good idea though, a dumbed down population needs more
sophisticated kit to compensate.

On Sun, 28 Aug 2011 16:02:52 +0000 (UTC), J G Miller
wrote:

On Sunday, August 28th, 2011 at 14:49:07h +0100, Brian Gaff explained:

This is what you get when a designer is not a person living in the real
world of the general public.

Are you suggesting that designers of some digital converter boxes are not
people or that they live on another world?

Do they all commute to work on this world from Tralfamadore?

Now THAT would explain a lot

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.

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.

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.

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?

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

Okay. I have just taken a look. I see what you mean. I think I was
mixing up the process for the Sony TV with the Humax box.

For the TV, as I now recall I used the Digital Auto Tuning which then
presented me with a choice of three transmitters. I was fortunate in
in selecting the correct one as the names were less than helpful.

Sorry about the confusion.

Jim Lesurf wrote:
In article , Bill Wright
wrote:
Jim Lesurf wrote:
In article , Bill Wright
wrote:
Here's a list of bandpass filters.
http://dl.dropbox.com/u/11023364/bandpass%20filters.doc
Has anyone (independent of the makers) done measurements on them and
put the results onto the web?

Slainte,

Jim

I checked out most of the ones listed merely to ensure that they did
roughly what they're supposed to, which they all did. There were no big
surprises regarding through loss, out-of-desired-band attenuation, etc.
Of course this wasn't a rigorous test; just a 'fit for purpose' test.

OK, could you perhaps sometime add those figures to the above document? It
would save those interested from having to re-chase the figures.

The tests were done very quickly and crudely. I wouldn't regard the
results as publishable. The trouble with the internet is that no matter
what riders and disclaimers you apply if you put a table of figures up
it will soon appear as gospel on various websites.

Bill

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

On Mon, 29 Aug 2011 20:36:19 +0100, Bob Latham
wrote:

41 42 43 44 45 46 47
Wrekin COM4 COM5 COM6
Sutton COM4 PSB1 COM5 PSB2
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