Band pass filters -- what am I missing?

"Bob Latham" wrote in message
...
In article ,
Clem Dye wrote:
I'm in an area served by two transmitters, one group A, the other group
B. The weaker group A stuff is being picked-up from the back of the
aerial. As a result, whenever I re-tune my DTV boxes the weaker channels
get allocated the lower numbers, the correct channels the 800 range.

I discovered this afternoon that my father has exactly the same problem.

He has an apartment (Kidderminster) which is fed from a communal aerial
system. It is designed for Sutton Coldfield but now suddenly pulls in
wrekin but the channels are good enough for the tv to allocate the lower
numbers to it but they break up something awful. I am going to fit a band
B filter and I'm also going to try using a 12 db attenuator. After tuning
I will remove the attenuator. Hope that works but what a fuss.

I think it will cause havoc on Sept 7th when everyone there has to retune,
Wrekin is too strong and out of band.


Bob.

They really didn't think much when they wrote the Freeview receiver spec did
they.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.

"Richard Tobin" wrote in message
...
In article ,
Mark Carver wrote:

Welcome to the world of hight power overlapping DTT. Folk in the
Manchester,
Liverpool, and Bristol Channel areas (to name but three) have been
struggling
with this problem for a while.

Why do TVs not let you simply choose a transmitter? There's an
identifier in the signal somewhere, because I've seen it displayed.

Because they're designed by idiots?

--

Brian Gregory. (In the UK)

To email me remove the letter vee.

On Sunday, August 28th, 2011 at 17:27:25h +0100, Mark Carver wrote:

That's fine, until the UHF channel allocations change !

Hence why I stated an "editable list".

so whose do you trust ?

UK Free TV?

It's all a shambles quite honestly.

Totally agree - can you name any other country undergoing
digital switchover which has forced people to do more than
one retune?

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?

J G Miller wrote:
On Sunday, August 28th, 2011 at 17:27:25h +0100, Mark Carver wrote:

That's fine, until the UHF channel allocations change !

Hence why I stated an "editable list".

Well, you're almost back to a 'manual tune' procedure then ? In other words
you have to know which transmitter you're using, and what its UHF allocations
are (at present!). In other words you need to be 'technically minded' in order
to perform a retune.

so whose do you trust ?

UK Free TV?

Ha ! Please !

It's all a shambles quite honestly.

Totally agree - can you name any other country undergoing
digital switchover which has forced people to do more than
one retune?

No, I don't think I can ?



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

www.paras.org.uk

In message , Brian Gaff
wrote
This is what you get when a designer is not a person living in the real
world of the general public.

and a regulator that doesn't care about what the public may want.

--
Alan
news2009 {at} admac {dot} myzen {dot} co {dot} uk

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?

Bill

Alan wrote:
In message , John
Rumm wrote

If the box supports manual scan... and of those that do, some have an
annoying habit of erasing all the stored channels each time you manual
scan. Hence you can only tune one mux.

And some boxes only add channels to the list when you scan so you first
have to reset to get rid of the previous scan information prior to new
scan.


Those little Philips boxes are very good. You can set the start and stop
scan channels or do the whole thing manually, and they display BER!

Bill

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.

Bill

In message , Richard Tobin
wrote

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

This is what I use on my Freeview box
http://www.admac.myzen.co.uk/mux_tuning/

--
Alan
news2009 {at} admac {dot} myzen {dot} co {dot} uk