In message , Don Pearce
writes



There is always a downside to individual channel filtering, and that
is the group delay that gets screwed at the edges, unless you also
have all-pass equalizers. It all tends to get a bit messy.

Indeed. Some of the analogue modulators etc used on many large cable TV
systems were designed to provide signals at least equalling broadcast
quality. Anything inserted thereafter could certainly screw things up to
some degree - effectively rendering the manufacturers' painstaking work
rather a waste of time!
--
Ian

In message ,
Terry Casey writes:
[]
Not a bomber - it would have been the A10 rocket.

The A10 was a prosed development of the A4 rocket that was the basis
for the V2 bombs that fell on London (as opposed to the jet engined V1
flying bomb known colloquially as the 'doodlebug' - I think the US term
is buzz-bomb).

To bring this back 'on course' - at least, for uk.tech.broadcast readers
- the A10 rocket is mentioned in this historic article:

http://lakdiva.org/clarke/1945ww/194...t_305-308.html

And there was a film - 1970s I think - very loosely based on it. If I
saw it now, I'd probably cringe at all sorts of errors in it, but I
remember enjoying it _as a film_, then. I think it might have been
"Operation Crossbow" - CBA to check.
--
J. P. Gilliver. UMRA: 1960/1985 MB++G.5AL-IS-P--Ch++(p)Ar@T0H+Sh0!:`)DNAf

All I ask is to _prove_ that money can't make me happy.

In article , says...

Ian Jackson wrote:

I recall that certain systems insisted that the four set-top
bypass channels had to be close to the standard off-air broadcast
channels, because some TV sets would not tune to anything but these.


They would have to be very unusual TV sets!
They existed. We used to have problems with a system that had crappy
modulators that drifted. Some of the tellys just wouldn't tune the
signals unless they were exactly on the channel. Just skipped over them.


Yes, as I've said in another post, I misinterpreted Ian's comment.

I've also come across sets that jump in 8MHz increments but have usually
found a 'fine tune' option buried deep down in the menu somewhere ...

That's usually when you find out that the remote is not working or has
been lost ...

--

Terry

In article ,
says...

In message ,
Terry Casey writes:
[]
Not a bomber - it would have been the A10 rocket.

The A10 was a prosed development of the A4 rocket that was the basis
for the V2 bombs that fell on London (as opposed to the jet engined V1
flying bomb known colloquially as the 'doodlebug' - I think the US term
is buzz-bomb).

To bring this back 'on course' - at least, for uk.tech.broadcast readers
- the A10 rocket is mentioned in this historic article:

http://lakdiva.org/clarke/1945ww/194...t_305-308.html

And there was a film - 1970s I think - very loosely based on it. If I
saw it now, I'd probably cringe at all sorts of errors in it, but I
remember enjoying it _as a film_, then. I think it might have been
"Operation Crossbow" - CBA to check.

1965, I think you'll find. The rocket in the film was supposed to be a
successor to the V2 and I'm sure that it is referred to as the V3 in the
film although, as I later found out, the V3 was a multi-barrelled high
velocity cannon, the site of which I've since visited.

http://en.wikipedia.org/wiki/Fortress_of_Mimoyecques

--

Terry

Arny Krueger wrote:

"Michael A. Terrell" wrote in message
...

Arny Krueger wrote:

"Michael A. Terrell" wrote in message
...

Arny Krueger wrote:

"Peter Larsen" wrote in message
k...
Ron wrote:

Surely you remember analogue TV Arny, it's when we had five
channels
of rubbish, now we have 900 channels and it's still rubbish

What's TV?

Something that can actually be enjoyable, useful and even a bit
educational,
managed well.

A capacious 2 channel DVR is a big help.

An internet ready BluRay is better. A lot of free TV via the
internet including classic movies, comedy and Sci-Fi.

We have the hardware for both. After experiencing a hands-on unfettered
comparison of the two for about a year, we kept the DVR and terminated
the
Internet service for the BluRay, but kept the stream of rental BD discs.


The BluRay was a one time investment of $80. Since I already have
broadband, there is no monthly fee. No need for a credit card, or trips
to one of the few remaining video stores, or to try to find something
worth watching in a 'Redbox'.

If you are obtaining current movies for just the cost of broadband, then you
are not paying the usual fees for viewing copyrighted materials. The
morality of that is up to you, but its not a fair comparison.


What morality? Sony owns the copyrights for the movies that they run
on 'Crackle'. I never said I was watching 'current movies'. On the
extremly rare chance that something cmes out I'll eiter watch it at a
theater, or buy the disk. Thre have been two 'current movies' in the
last 12 years that I wanted to see.


In the US the usual fee for obtaining a fairly current movie over broadband
is about $5 each. Netflix over broadband is more like $9 per month, but the
catalog is severely limited, both in terms of movies and also TV shows.


Not everyone is addicted to the latest Hollywood drivel. I 'watch'
about 10-15 hours a week and a lot of that is local news. When I do
watch more, it's when I'm too ill to do aything else.


Redbox is the price/performance winner around here, and their nearest
machine is within easy driving or biking distance.


Good for you. The nearest Redbox is about three miles, but I've
never seen a title I wanted to watch.


--
You can't have a sense of humor, if you have no sense.

Ian Jackson wrote:

In message , Michael A.
Terrell writes

Terry Casey wrote:

In article ,
says...

David Looser wrote:

"Michael A. Terrell" wrote in message
m...

"Geoffrey S. Mendelson" wrote:

hwh wrote:
On 2/5/12 7:04 PM, J. P. Gilliver (John) wrote:
But you've got to remember that this is the country that
405-line
going for, I think, longer after 625 started than it had been going
before that.

Erm, 405 started before the war and was alone until 1964? Then it
continued for another 20 years?

Someone said the last two years of 405 line signals were
generated by an
unusal
method, I think the word they used was "endearing". What was it?

BTW, the BBC shut down TV broadcasts in for World War II, and resumed
them at the exact point in the same broadcast after the war. :-)


That's very easy to do with film. I should know. I loaded and ran
truckloads of 16 mm film on a pair of RCA TP66 projectors in the '70s.

I'm sure it is, but as we've already established that the "exact point in
the same broadcast" bit isn't true its not relevant.

The myth that the engineers simply ceased transmission half-way through a
programme and left the station like a sort of Mary Celeste has been
widespread, but it is a myth. In fact there was an orderly shut
and the
film in the machines would have been rewound and put into storage
before the
staff left. It would have been 35mm film (the BBC didn't have
facilities for
transmitting from 16mm film pre-war) and thus on nitrate stock.
putting
it into proper storage would have constituted a fire hazard and been in
contravention of fire regulations.


It still would have been no problem to load and start it at exactly
the same frame, if they had wanted to.

All hypothetical. As David said earlier, it is a myth that transmission
was cut in the middle of the cartoon. Station logs exist that say
different.

Another myth is that the Television Service resumed in 1946 with the
same cartoon. It didn't!

The cartoon WAS repeated that day - but it wasn't the first programme.


Does it matter? Were you alive to see it, and in their service
area? I wasn't and I wasn't. I was a TV broadcast engineer at three US
TV stations from the early '70s to the late '80s. I started with
monochrome and film, and ended up with 1" Sony color VTRS & RCA TK46A
cameras feeding a 5 MW EIRP antenna 1700+ feet AAT.

I'm sure that that the point being made was that despite all that had
happened to Britain since 1939, we were now picking up the pieces,
continuing where we had left off, and getting back to business as usual.
Even if it didn't quite happen as reported, there is no doubt that the
popular version of the story would have been good for moral.


Or an attempt to raise the moral of the citizens after VE day?

--
You can't have a sense of humor, if you have no sense.

On Thursday, February 9th, 2012, at 08:27:09h -0500, Arny Krueger wrote:

In all seriousness, Europe has settled down a lot since WW2 and then the
cold war.

The Great War started in the Balkans with the assassination of Arch Duke Ferdinand.

The Balkan nations had another attempt at a conflagration in the 1990s in which
the US once again played a role.

Terry Casey wrote:
In article , says...
The manufacturers of many of the modulators sold for communal TV system
use claim that the output is so clean that filter combiners are
unnecessary. But I use filters anyway. The fact is that I seem to get
better results.


I wonder if they have any active stages AFTER the filter, possibly
because they might be used in installations with less than perfect
matching?
Mebbe so, I hadn't thought of it. The out-of-channel noise from them is
impressively low, but with twenty of them it adds up.


We used to use some tunable modulators, although most of them were
fixed. The idea of the tuneable one was that you had a near instant fix
if one of the modulators developed a fault. The downside was that the
broadband noise from the unfiltered output degraded the headend by 1dB
per modulator ...
That sounds about right! The most amazing thing I ever saw like that was
at the old Visnews place at Park Royal. They had a system done by
'experts' who I dare not name even now. The modulators were terrible. No
kidding they drifted 1/4 of a channel if you put your hand on the case.
Their outputs were combined with a 20-way resistive star network. The
result was the most horrendous garbage you've ever seen. The modulator
outputs after the combiner were -10dBmV and the noise was about 6dB
below that! Of course there was a lot of amplification following, and a
lot of cross mod because in attempts to get rid of the snow and
patterning people had turned everything up. Hilariously, before I went
to it they had the local aerial firm round and they'd metered the C Pal
signal at one outlet and diagnosed 'weak signal' so they'd fitted a
massive high gain aerial! This was looking at C Pal which was about five
miles away. Happy days!


Obviously you will add noise to the amplified source but not to the rest
of the system.

Well yes, but better to add a little noise there than let the channel go
through the system 10dB down.

Bill

Dave Plowman (News) wrote:


You see, you need to think for yourself about each issue, not just
blindly follow the party line.

Seems you often do just that. Too many 'Mail' generalizations.
I'm going to have to have a look at this 'Mail'. Is it really so bad as
everyone makes out?


Incidentally I think the present government has been duplicitous in the
extreme over the NHS, when you compare pre-election promises with the
present reality.

And you expected different?
No I didn't. I knew they were lying. I don't like the Tory party at all,
but I like Labour a lot less.

Bill

Terry Casey wrote:
In article , says...
Ian Jackson wrote:

I recall that certain systems insisted that the four set-top
bypass channels had to be close to the standard off-air broadcast
channels, because some TV sets would not tune to anything but these.

They would have to be very unusual TV sets!
They existed. We used to have problems with a system that had crappy
modulators that drifted. Some of the tellys just wouldn't tune the
signals unless they were exactly on the channel. Just skipped over them.


Yes, as I've said in another post, I misinterpreted Ian's comment.

I've also come across sets that jump in 8MHz increments but have usually
found a 'fine tune' option buried deep down in the menu somewhere ...

That's usually when you find out that the remote is not working or has
been lost ...

I remember some sets that jumped in 8MHz increments but if the signal
was not exactly on channel the set would jump over it, so there was no
chance to fine tune.

Bill