[John Williamson]

On 25/09/2015 18:57, JackA wrote:
When Angus mention a "plate" and "heater", was he warming his dinner or referring to vacuum tubes? You didn't jump in there and correct him, it's "filament", not a "heater". Don't think I'm being a wise-a**, just TRYING to understand the need for expertise here when we all knew what Mark meant.

No. It's a heater on both sides of the Atlantic. A filament is what's in
a light bulb, the heater in a valve (Tube to you Leftpondians) heats up
the cathode to a dull red heat to encourage it to emit electrons, Hence
"heater". Occasionally, the heater and the cathode are the same piece of
metal, but it's still not a filament.

The filament in a light bulb is the bit that glows white(ish) to make it
work.

The "plate" in a Leftpondian "tube" is what us Rightpondians call an
anode in a valve, while we all agree on grid for the grid(s) of wires
between the cathode and the anode which control the current flow.

--
Tciao for Now!

John.

[Scott Dorsey]

John Williamson wrote:

The delay from any single signal source to the listening position is a
linear function of the distance from each speaker, with a constant part
due to any delay in the electronics, which on a decent system can be
ignored, and as the listener moves round, the relative phases of the
sounds from the speakers alters, assuming the cones move in and out at
the same time. This is why I would refer to speakers correctly connected
as being in phase.

That does not follow.

If you add a delay line to one speaker, they no
longer move at the same time, so are not in phase.

Yes.

Changing the relative
polarity of the speakers would, to me, involve reversing the connections
on one speaker so that the cones no longer move in the same direction at
the same time when fed an identical signal, so the cone movement is 180
degrees out of phase.

No, is is 180 degrees out of polarity. In the case of a sine wave, you
could think of this as being equivalent to a phase shift, but in the case
of any other waveform (like music), you cannot.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Mike Rivers[_2_]]

On 9/25/2015 2:10 PM, John Williamson wrote:
No. It's a heater on both sides of the Atlantic. A filament is what's in
a light bulb, the heater in a valve

We use "filament" in tube talk here in the colonies. It's even in my RCA
Tube Manual. "Heater" is usually used when you have a directly heated
cathode, whereas "filament" is the generic term and is typically used
when the cathode is indirectly heated.

--
For a good time, visit http://mikeriversaudio.wordpress.com

[JackA]

On Friday, September 25, 2015 at 2:10:14 PM UTC-4, John Williamson wrote:
On 25/09/2015 18:57, JackA wrote:
When Angus mention a "plate" and "heater", was he warming his dinner or referring to vacuum tubes? You didn't jump in there and correct him, it's "filament", not a "heater". Don't think I'm being a wise-a**, just TRYING to understand the need for expertise here when we all knew what Mark meant.

No. It's a heater on both sides of the Atlantic. A filament is what's in
a light bulb, the heater in a valve (Tube to you Leftpondians) heats up
the cathode to a dull red heat to encourage it to emit electrons, Hence
"heater". Occasionally, the heater and the cathode are the same piece of
metal, but it's still not a filament.

The filament in a light bulb is the bit that glows white(ish) to make it
work.

The "plate" in a Leftpondian "tube" is what us Rightpondians call an
anode in a valve, while we all agree on grid for the grid(s) of wires
between the cathode and the anode which control the current flow.

Wait a second, are we talking vacuum tubes or valves? Depends where you reside!!
Peter, help!!!

Yeah, electric company updating power grid. Guess control and screen are sufficient, in Tubeville.

Funny :-)

Jack


--
Tciao for Now!

John.

[John Williamson]

On 25/09/2015 19:32, Mike Rivers wrote:
On 9/25/2015 2:10 PM, John Williamson wrote:
No. It's a heater on both sides of the Atlantic. A filament is what's in
a light bulb, the heater in a valve

We use "filament" in tube talk here in the colonies. It's even in my RCA
Tube Manual. "Heater" is usually used when you have a directly heated
cathode, whereas "filament" is the generic term and is typically used
when the cathode is indirectly heated.

I slouch corrected.

--
Tciao for Now!

John.

[JackA]

On Friday, September 25, 2015 at 2:21:53 PM UTC-4, Scott Dorsey wrote:
John Williamson wrote:

The delay from any single signal source to the listening position is a
linear function of the distance from each speaker, with a constant part
due to any delay in the electronics, which on a decent system can be
ignored, and as the listener moves round, the relative phases of the
sounds from the speakers alters, assuming the cones move in and out at
the same time. This is why I would refer to speakers correctly connected
as being in phase.

That does not follow.

If you add a delay line to one speaker, they no
longer move at the same time, so are not in phase.

Yes.

Changing the relative
polarity of the speakers would, to me, involve reversing the connections
on one speaker so that the cones no longer move in the same direction at
the same time when fed an identical signal, so the cone movement is 180
degrees out of phase.

No, is is 180 degrees out of polarity. In the case of a sine wave, you
could think of this as being equivalent to a phase shift, but in the case
of any other waveform (like music), you cannot.

P(hase)AL vs NTSC!!! USA accepted the inferior format.


Jack

--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[[email protected]]

Wow, I didn't intend to open this can of worms (again)

POLARITY _is_ the correct term to use refering to wiring speakers.

However the term PHASE has been (mis)used for such a long time (as in the phase inverter stage to drive the push pull outputs) that in order to communicte clearly sometimes you have to use the wrong term.

Mark

[JackA]

On Friday, September 25, 2015 at 3:14:01 PM UTC-4, wrote:
Wow, I didn't intend to open this can of worms (again)

-- Didn't Phase us at all!

Jack


POLARITY _is_ the correct term to use refering to wiring speakers.

However the term PHASE has been (mis)used for such a long time (as in the phase inverter stage to drive the push pull outputs) that in order to communicte clearly sometimes you have to use the wrong term.

Mark

[Les Cargill[_4_]]

Scott Dorsey wrote:
Roy W. Rising wrote:
(Scott Dorsey) wrote:
[snip]

I do still correct people for saying "wire" when they mean cable and
"filming" when they mean "video recording," though.

Throughout the era of videotape recording, I gave 'em slack. After all,
videotape is a kind of "film". Now that we've gone digital, I'm seeking a
shorter expression than "video recording". "Videoing" doesn't work for me.
Any suggestions?

If it's perforated, you're filming! If it's not perforated, you're taping!

These days, though, most folks aren't filming OR taping... I don't have a
good word but 'shooting' is sufficiently generic to be inoffensive.
--scott


FLASHing? No, probably too close to other uses of the word...

--
Les Cargill

[Roy W. Rising[_2_]]

(Scott Dorsey) wrote:
Roy W. Rising wrote:
(Scott Dorsey) wrote:
[snip]

I do still correct people for saying "wire" when they mean cable and
"filming" when they mean "video recording," though.

Throughout the era of videotape recording, I gave 'em slack. After all,
videotape is a kind of "film". Now that we've gone digital, I'm seeking
a shorter expression than "video recording". "Videoing" doesn't work
for me. Any suggestions?

If it's perforated, you're filming! If it's not perforated, you're
taping!

These days, though, most folks aren't filming OR taping... I don't have a
good word but 'shooting' is sufficiently generic to be inoffensive.
--scott

Or, perhaps "viding".

--
~ Roy
"If you notice the sound, it's wrong!"

[Scott Dorsey]

Roy W. Rising wrote:
Or, perhaps "viding".

I would agree that a lot of the television programming today is pretty
"vide" to begin with.

Which reminds me.... Roy, have you ever seen a Port-O-Vox wireless mike?
I bought some junk from the Family Channel recently which included a box
of spare parts for the things because I am a sucker for submini tubes.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Les Cargill[_4_]]

Roy W. Rising wrote:
(Scott Dorsey) wrote:
Roy W. Rising wrote:
(Scott Dorsey) wrote:
[snip]

I do still correct people for saying "wire" when they mean cable and
"filming" when they mean "video recording," though.

Throughout the era of videotape recording, I gave 'em slack. After all,
videotape is a kind of "film". Now that we've gone digital, I'm seeking
a shorter expression than "video recording". "Videoing" doesn't work
for me. Any suggestions?

If it's perforated, you're filming! If it's not perforated, you're
taping!

These days, though, most folks aren't filming OR taping... I don't have a
good word but 'shooting' is sufficiently generic to be inoffensive.
--scott

Or, perhaps "viding".


In NADSAT, that's "viddying", with an uncomfortable profusion of
vowels.

--
Les Cargill

[Roy W. Rising[_2_]]

(Scott Dorsey) wrote:
Roy W. Rising wrote:
Or, perhaps "viding".

I would agree that a lot of the television programming today is pretty
"vide" to begin with.

Which reminds me.... Roy, have you ever seen a Port-O-Vox wireless mike?
I bought some junk from the Family Channel recently which included a box
of spare parts for the things because I am a sucker for submini tubes.
--scott

That's new to me. The earliest ones I encountered were from Comrex. They
were used on General Hospital with RCA BK6 mics, back when tape machines
were steam powered. ;-)

--
~ Roy
"If you notice the sound, it's wrong!"

[Angus Kerr]

On Friday, September 25, 2015 at 8:32:33 PM UTC+2, Mike Rivers wrote:
On 9/25/2015 2:10 PM, John Williamson wrote:
No. It's a heater on both sides of the Atlantic. A filament is what's in
a light bulb, the heater in a valve

We use "filament" in tube talk here in the colonies. It's even in my RCA
Tube Manual. "Heater" is usually used when you have a directly heated
cathode, whereas "filament" is the generic term and is typically used
when the cathode is indirectly heated.


In about 1981, I had a holiday (vacation) job working for David Manley, one of the most interesting characters I have met. He was restoring a bunch of Leak Williamson amplifiers, and I had the task of wiring up the harness and soldering all of the valve (tube) sockets.

I was only 16 at the time, so I did not have the capacity to understand how the tubes actually worked, but I did get to hear how beautiful valves (tubes) sound with my fresh 16 year old ears.

Wish that I actually got to own a pair of those Leaks. He did give me a Radford STA25 power amplifier, which I must have traded for some awful higher powered BJT amplifier. 16 - young, dumb, and full of ****.

Anyway, to cut a long story short, to my memory, he called the tube a valve, the filament circuit the heater circuit, the anode the plate, and the grid the grid. That's where I got the terms from.

In all my years as an electrical engineer, I have never understood what makes an anode an anode and what makes a cathode a cathode. I hate those terms - if you ask me which is which on a simple diode, I'll probably get it wrong.

-Angus.

[Mike Rivers[_2_]]

On 9/27/2015 5:07 AM, Angus Kerr wrote:

In about 1981, I had a holiday (vacation) job working for David
Manley, one of the most interesting characters I have met.

Anyway, to cut a long story short, to my memory, he called the tube a
valve, the filament circuit the heater circuit, the anode the plate,
and the grid the grid. That's where I got the terms from.

In all my years as an electrical engineer, I have never understood
what makes an anode an anode and what makes a cathode a cathode.

From a Wikipedia page:

"The word was coined in 1834 from the Greek κάθοδος (kathodos),
'descent' or 'way down', by William Whewell, who had been consulted[2]
by Michael Faraday over some new names needed to complete a paper on the
recently discovered process of electrolysis. In that paper Faraday
explained that when an electrolytic cell is oriented so that electric
current traverses the "decomposing body" (electrolyte) in a direction
"from East to West, or, which will strengthen this help to the memory,
that in which the sun appears to move", the cathode is where the current
leaves the electrolyte, on the West side: "kata downwards, `odos a way ;
the way which the sun sets".[3][4]

The use of 'West' to mean the 'out' direction (actually 'out' †’ 'West' †’
'sunset' †’ 'down', i.e. 'out of view') may appear unnecessarily
contrived. Previously, as related in the first reference cited above,
Faraday had used the more straightforward term "exode" (the doorway
where the current exits). His motivation for changing it to something
meaning 'the West electrode' (other candidates had been "westode",
"occiode" and "dysiode") was to make it immune to a possible later
change in the direction convention for current, whose exact nature was
not known at the time. The reference he used to this effect was the
Earth's magnetic field direction, which at that time was believed to be
invariant. He fundamentally defined his arbitrary orientation for the
cell as being that in which the internal current would run parallel to
and in the same direction as a hypothetical magnetizing current loop
around the local line of latitude which would induce a magnetic dipole
field oriented like the Earth's. This made the internal current East to
West as previously mentioned, but in the event of a later convention
change it would have become West to East, so that the West electrode
would not have been the 'way out' any more. Therefore, "exode" would
have become inappropriate, whereas "cathode" meaning 'West electrode'
would have remained correct with respect to the unchanged direction of
the actual phenomenon underlying the current, then unknown but, he
thought, unambiguously defined by the magnetic reference. In retrospect
the name change was unfortunate, not only because the Greek roots alone
do not reveal the cathode's function any more, but more importantly
because, as we now know, the Earth's magnetic field direction on which
the "cathode" term is based is subject to reversals whereas the current
direction convention on which the "exode" term was based has no reason
to change in the future.

Since the later discovery of the electron, an easier to remember, and
more durably technically correct (although historically false),
etymology has been suggested: cathode, from the Greek kathodos, 'way
down', 'the way (down) into the cell (or other device) for electrons'."

Once you get past why a cathode is called a cathode, anode is easy. The
prefix "an" means "not," a shortened form of "not a cathode." But this
doesn't help.

As far as the diode symbol goes, that makes a lot of sense. The cathode
is the arrow that points to the line (plate in a vacuum tube) as
"(conventional) current flows in this direction."


--
For a good time, visit http://mikeriversaudio.wordpress.com

[Scott Dorsey]

In article , Mike Rivers wrote:
"The word was coined in 1834 from the Greek κάθοδος (kathodos),
'descent' or 'way down', by William Whewell, who had been consulted[2]
by Michael Faraday over some new names needed to complete a paper on the
recently discovered process of electrolysis. In that paper Faraday

"The current, it flows from the source to the sink, from the minus to the
plus, from the cathode to the anode, from the supply to the load."
-- Dr. Ibe

Dr. Ibe said this so often in class that it became a standard recitation
stuck in everyone's head. Of course, some of that is reversed in the US
military where current and electron flow in the same direction.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

Roy W. Rising wrote:

That's new to me. The earliest ones I encountered were from Comrex. They
were used on General Hospital with RCA BK6 mics, back when tape machines
were steam powered. ;-)

I came in a good bit later, with the Vega low-band VHF units. Tiny
transmitters with big antennas...
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Roy W. Rising[_2_]]

(Scott Dorsey) wrote:
Roy W. Rising wrote:

That's new to me. The earliest ones I encountered were from Comrex.
They were used on General Hospital with RCA BK6 mics, back when tape
machines were steam powered. ;-)

I came in a good bit later, with the Vega low-band VHF units. Tiny
transmitters with big antennas...
--scott

The early Vegas were a welcome step. At first they shipped with a small
dynamic mic, AKG? Then the Sony ECM50 overhauled the world. (I have a few,
if anyone likes vintage. They're huge by today's standards.) Little
Richard slipped while dancing on top of his piano. The Vega's thin
aluminum case was flattened. I asked the guys in the "lab" to find a way
to power the Sonys from the Vega Xmtr. They did it and a new technology
was launched. Sadly, the Vegas were long-pre-dual-diversity. The RF
"hits" were deadly.

One of the best steps forward was when John Nady came up with working
compansion. He holds the patent but lets everyone use it freely. That
includes MTS TV Stereo. We first tried the Nady system on Richard Dawson
for Family Feud. "Clapping" came through with no HF content. John said
"There's a capacitor value I'll change. I never contemplated wireless
drums!"

--
~ Roy
"If you notice the sound, it's wrong!"

[Peter Larsen[_3_]]

On 27-09-2015 10:07, Angus Kerr wrote:

Wish that I actually got to own a pair of those Leaks. He did give me a Radford STA25 power amplifier, which I must have traded for some awful ...

There is a re-release series, ridiculously expensive. And I don't have
that kind of money. Otherwise I'd be seriously tempted even at GBP 1800
to get one again to replace the one I sold for DKK 1000 in 1982. It was
perhaps not a bad choice, it was beginning to need a major refurb,
probably even new pcbs ... they were brown and charred around the
sockets. But sometimes I still kinda want to hear something played back
on it ...

-Angus.

Kind regards

Peter Larsen

[Trevor]

On 26/09/2015 2:21 AM, Scott Dorsey wrote:
If it's perforated, you're filming! If it's not perforated, you're taping!

So in an attempt to be pedantic, you simply actually make up your own
definitions. What's the point? As already pointed out, magnetic tape is
simply an oxide layer deposited on plastic film.
Nothing more stupid than arguing semantics when you don't even
understand the derivation of language. "Taping" could just as easily be
applying sticky tape! :-)

Trevor.

[John Williamson]

On 28/09/2015 07:37, Trevor wrote:
On 26/09/2015 2:21 AM, Scott Dorsey wrote:
If it's perforated, you're filming! If it's not perforated, you're
taping!

So in an attempt to be pedantic, you simply actually make up your own
definitions. What's the point? As already pointed out, magnetic tape is
simply an oxide layer deposited on plastic film.
Nothing more stupid than arguing semantics when you don't even
understand the derivation of language. "Taping" could just as easily be
applying sticky tape! :-)

Common usage here seems to be "filming", "making a film" or "making a
movie" when it's for pubic consumption at the cinema or on TV, while
"videoing" denotes either an amateur making home movies or the guy at
the wedding with a video camera, who's probably also doing the stills of
the event. Videoing is also used to denote company promotional stuff and
the Chairman's speech trying to jolly up the workers...

The actual recording material used doesn't seem to matter, as the public
still assume there are massive reels of 35mm film whizzing round in the
projection booth, rather than a couple of hard drives. They also still
tend to associate video tape with home movies, even though we're all
using hard drive or flash memory based cameras now.


--
Tciao for Now!

John.

[Angus Kerr]

On Sunday, September 27, 2015 at 7:18:27 PM UTC+2, Peter Larsen wrote:
On 27-09-2015 10:07, Angus Kerr wrote:

Wish that I actually got to own a pair of those Leaks. He did give me a Radford STA25 power amplifier, which I must have traded for some awful ...

There is a re-release series, ridiculously expensive. And I don't have
that kind of money. Otherwise I'd be seriously tempted even at GBP 1800
to get one again to replace the one I sold for DKK 1000 in 1982. It was
perhaps not a bad choice, it was beginning to need a major refurb,
probably even new pcbs ... they were brown and charred around the
sockets. But sometimes I still kinda want to hear something played back
on it ...

Unfortunately, mine was absolutely mint. Nothing wrong with it, just a 16 year olds messed up head.

I still don't think it sounded as good as the Leak Williamson.

Well, that ship sailed. We'll have to try to find one in a pawn shop...

-Angus.

[None]

"Trevor" wrote in message
...
Nothing more stupid than arguing semantics when you don't even
understand the derivation of language.

I think the argument is about vocabulary, not semantics; and although
the derivation may be interesting, it has little bearing on modern
usage.

[None]

"John Williamson" wrote in message
...
as the public still assume there are massive reels of 35mm film
whizzing round in the projection booth,

Only the elderly.

[[email protected]]

On Monday, September 28, 2015 at 8:16:50 AM UTC-4, None wrote:
"John Williamson" wrote in message
...
as the public still assume there are massive reels of 35mm film
whizzing round in the projection booth,

Only the elderly.

OK...so what is the technology used in a typical movie theater these days?

If it is a video projector and file server, what is the typical resolution?

Mark

[Scott Dorsey]

Roy W. Rising wrote:
The early Vegas were a welcome step. At first they shipped with a small
dynamic mic, AKG? Then the Sony ECM50 overhauled the world. (I have a few,
if anyone likes vintage. They're huge by today's standards.) Little
Richard slipped while dancing on top of his piano. The Vega's thin
aluminum case was flattened. I asked the guys in the "lab" to find a way
to power the Sonys from the Vega Xmtr. They did it and a new technology
was launched. Sadly, the Vegas were long-pre-dual-diversity. The RF
"hits" were deadly.

I worked on a surf movie years ago, where they were filming surfers from
the beach with some crazy long makeshift optics as well as from the water,
and someone had the idea of planting a Vega mike on the board. So we're
sitting on the beach with a Uher 4000 and one of these enormous Vega receivers
with VFO right above a reflective ocean surface and sometimes below it.
I think in two days we maybe got a couple seconds of usable audio.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Scott Dorsey]

wrote:
On Monday, September 28, 2015 at 8:16:50 AM UTC-4, None wrote:
"John Williamson" wrote in message
...
as the public still assume there are massive reels of 35mm film
whizzing round in the projection booth,

Only the elderly.

OK...so what is the technology used in a typical movie theater these days?

If it is a video projector and file server, what is the typical resolution?

It is likely to be a video projector and file server with 4K resolution.
Some larger halls may have 8K but it is fairly rare.

The real issue with the digital cinema systems isn't resolution so much as
grey scale; even the better systems don't have the long tonal range of even
color film prints, let alone good B&W.

The digital systems don't look as good as a good film print, but they look
a whole lot better than a bad film print. Many years ago they would
make a dozen prints of a blockbuster and show them in LA and NYC first,
then nine months later they would have trickled down the system and the
film would be showing here in Williamsburg, VA.

But today they want to premiere the film everywhere in the country at the
same time, then drop it after a two-week run. This means making thousands
of film prints (which means those prints are several generations of interneg
and interpos down) and it means people don't take care of them because they
aren't headed to another theatre after the first run.

Consequently, the film prints your local multiplex has been getting for the
past couple decades have been pretty awful, and the digital systems are a
big step up for them. On the other hand, you go and watch a first generation
EK print at Grauman's and it's going to look a lot better than the digital
systems.
--scott

Mark


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Angus Kerr]

In all my years as an electrical engineer, I have never understood
what makes an anode an anode and what makes a cathode a cathode.

From a Wikipedia page:

-long snip-
Once you get past why a cathode is called a cathode, anode is easy. The
prefix "an" means "not," a shortened form of "not a cathode." But this
doesn't help.

As far as the diode symbol goes, that makes a lot of sense. The cathode
is the arrow that points to the line (plate in a vacuum tube) as
"(conventional) current flows in this direction."


jokesOk, so after a glass of wine, this makes perfect sense. /jokes
I just like + and -. I also kind of like and use conventional current flow, from + to -, as the holes flow, as the diode symbol really seems daft if you are considering electron flow. I have an old US military series of videos on electrical engineering (amazing stuff), and I had to laugh as they explained all this stuff with negative electron flow. The current goes the wrong way through the diode. I am so glad I can google these days which the cathode is, because, even with the historical explanation, I've got a 50/50 chance of getting it wrong.

-A.

btw, thank you for the Wiki explanation and research.....

[JackA]

On Monday, September 28, 2015 at 12:32:54 PM UTC-4, Angus Kerr wrote:
In all my years as an electrical engineer, I have never understood
what makes an anode an anode and what makes a cathode a cathode.

From a Wikipedia page:

-long snip-
Once you get past why a cathode is called a cathode, anode is easy. The
prefix "an" means "not," a shortened form of "not a cathode." But this
doesn't help.

As far as the diode symbol goes, that makes a lot of sense. The cathode
is the arrow that points to the line (plate in a vacuum tube) as
"(conventional) current flows in this direction."


jokesOk, so after a glass of wine, this makes perfect sense. /jokes
I just like + and -.


Then use a Selenium rectifier!

Jack


I also kind of like and use conventional current flow, from + to -, as the holes flow, as the diode symbol really seems daft if you are considering electron flow. I have an old US military series of videos on electrical engineering (amazing stuff), and I had to laugh as they explained all this stuff with negative electron flow. The current goes the wrong way through the diode. I am so glad I can google these days which the cathode is, because, even with the historical explanation, I've got a 50/50 chance of getting it wrong.

-A.

btw, thank you for the Wiki explanation and research.....

[[email protected]]

One of the best steps forward was when John Nady came up with working
compansion. He holds the patent but lets everyone use it freely. That
includes MTS TV Stereo. We first tried the Nady system on Richard Dawson
for Family Feud. "Clapping" came through with no HF content. John said
"There's a capacitor value I'll change. I never contemplated wireless
drums!"

--
~ Roy

I have a well known brand name wireless mic (not Nady) that is marketed for PA system work (not as stingent as network broadcast) and it includes the standard NE571 companding system. The design of this particular unit had a flaw. When the RF signal would get a little weak, the broadband noise in the recovered audio would be detected by the expander and the expander would decide that this is an audio signal and it needs to be made louder. So if the propgation path was marginal, as the speaker walks around instead of some low level hiss and a dropout now and then, there would be LOUD static and feedback as the gain was incorrectly raised. Totaly unacceptable.

I had to increase a shunt cap value in the expander to roll off the expander detectors high frequency response to solve this problem. But you are correct, the compander now does not track really well on high frequency audio material, but I decided this was the lesser of the two evils. It is fine for most spectrally balanced material.

Mark

[Trevor]

On 28/09/2015 10:15 PM, None wrote:
"Trevor" wrote in message
...
Nothing more stupid than arguing semantics when you don't even
understand the derivation of language.

I think the argument is about vocabulary, not semantics; and although
the derivation may be interesting, it has little bearing on modern usage.

But that's the point, he is trying to narrowly define usage to suit
himself (in the parts you snipped) and "modern usage" is pretty much
anything goes. Those who don't like it should just do what THEY want,
and shut up about what others choose to do.

Trevor.

[Trevor]

On 28/09/2015 10:16 PM, None wrote:
"John Williamson" wrote in message
...
as the public still assume there are massive reels of 35mm film
whizzing round in the projection booth,

Don't assume everyone thinks like you. The percentage would be pretty
small these days.

Only the elderly.

How elderly do you have to be? I know 90 YO's who understand digital
cinema quite well. With so many on the internet these days I'm not
surprised either. There are a few technophobes in all age groups though.

Trevor.

[Trevor]

On 29/09/2015 12:08 AM, wrote:
OK...so what is the technology used in a typical movie theater these days?

If it is a video projector and file server, what is the typical resolution?

4K systems (not the same as consumer UHD often referred to as 4K) is
pretty much the standard now, but these things are changing all the
time. Not simply just resolution either.

Trevor.

[Trevor]

On 29/09/2015 12:43 AM, Scott Dorsey wrote:
The real issue with the digital cinema systems isn't resolution so much as
grey scale; even the better systems don't have the long tonal range of even
color film prints, let alone good B&W.

The digital systems don't look as good as a good film print, but they look
a whole lot better than a bad film print. Many years ago they would
make a dozen prints of a blockbuster and show them in LA and NYC first,
then nine months later they would have trickled down the system and the
film would be showing here in Williamsburg, VA.

But today they want to premiere the film everywhere in the country at the
same time, then drop it after a two-week run. This means making thousands
of film prints (which means those prints are several generations of interneg
and interpos down) and it means people don't take care of them because they
aren't headed to another theatre after the first run.

Consequently, the film prints your local multiplex has been getting for the
past couple decades have been pretty awful, and the digital systems are a
big step up for them. On the other hand, you go and watch a first generation
EK print at Grauman's and it's going to look a lot better than the digital
systems.
--scott

True, many years ago. Fortunately digital resolution, dynamic range,
color space, color accuracy and possible frame rates have now surpassed
the best film stock available. And superior audio of course.
Which is not to say ALL digital theatres are necessarily better than
film ones, and certainly not vice versa.

Trevor.

[Trevor]

On 29/09/2015 2:32 AM, Angus Kerr wrote:
In all my years as an electrical engineer, I have never
understood what makes an anode an anode and what makes a cathode
a cathode.

From a Wikipedia page:

-long snip-
Once you get past why a cathode is called a cathode, anode is easy.
The prefix "an" means "not," a shortened form of "not a cathode."
But this doesn't help.

As far as the diode symbol goes, that makes a lot of sense. The
cathode is the arrow that points to the line (plate in a vacuum
tube) as "(conventional) current flows in this direction."


jokesOk, so after a glass of wine, this makes perfect sense.
/jokes I just like + and -. I also kind of like and use
conventional current flow, from + to -, as the holes flow, as the
diode symbol really seems daft if you are considering electron flow.
I have an old US military series of videos on electrical engineering
(amazing stuff), and I had to laugh as they explained all this stuff
with negative electron flow. The current goes the wrong way through
the diode. I am so glad I can google these days which the cathode is,
because, even with the historical explanation, I've got a 50/50
chance of getting it wrong.

When I did EE 40 years ago we learned both conventional and electron
flow. Far from 50/50 chance of getting it wrong, I could always work
either way.
As for the diode symbol, I just assume an arrow for conventional, or an
old fashioned blunderbuss for electron flow. :-)
In any case how hard is it to understand electron flow is simply the
reverse of conventional flow? And if you know which flows +to- and which
-to+, the rest simply follows. Since neither is an exact representation
of what is really happening, it hardly matters which you choose IMO.

Trevor.

[[email protected]]

On Tuesday, September 29, 2015 at 5:03:03 AM UTC-4, Trevor wrote:


True, many years ago. Fortunately digital resolution, dynamic range,
color space, color accuracy and possible frame rates have now surpassed
the best film stock available. And superior audio of course.
Which is not to say ALL digital theatres are necessarily better than
film ones, and certainly not vice versa.

Trevor.


And what scares me about video projectors in movie theaters
is they give projectionists unprecedented control over the
local picture quality(adjustments such as contrast, brightness,
color, tint, etc). I can see management of theaters trying
to drum up business by advertising "BRIGHTER, SHARPER, MORE
COLORFUL" than "ANY OTHER THEATRE IN TOWN!!!". In a theater
chain with digital projection, how can movie-goers be
guaranteed they're seeing exactly(or close to) the director
& producer's original intentions?


Previously, the only adjustment projectionists or techs had
up in the booth was Focus! And of course, scheduled
replacement of projector bulbs.

[None]

wrote in message
...
And what scares me about video projectors in movie theaters
is they give projectionists unprecedented control over the
local picture quality(adjustments such as contrast, brightness,
color, tint, etc). I can see management of theaters trying
to drum up business by advertising "BRIGHTER, SHARPER, MORE
COLORFUL" than "ANY OTHER THEATRE IN TOWN!!!". In a theater
chain with digital projection, how can movie-goers be
guaranteed they're seeing exactly(or close to) the director
& producer's original intentions?

Can't you find a video group where you can flog that hobbyhorse?

[[email protected]]

On Tuesday, September 29, 2015 at 7:04:15 AM UTC-4, wrote:
On Tuesday, September 29, 2015 at 5:03:03 AM UTC-4, Trevor wrote:


True, many years ago. Fortunately digital resolution, dynamic range,
color space, color accuracy and possible frame rates have now surpassed
the best film stock available. And superior audio of course.
Which is not to say ALL digital theatres are necessarily better than
film ones, and certainly not vice versa.

Trevor.


And what scares me about video projectors in movie theaters
is they give projectionists unprecedented control over the
local picture quality(adjustments such as contrast, brightness,
color, tint, etc). I can see management of theaters trying
to drum up business by advertising "BRIGHTER, SHARPER, MORE
COLORFUL" than "ANY OTHER THEATRE IN TOWN!!!". In a theater
chain with digital projection, how can movie-goers be
guaranteed they're seeing exactly(or close to) the director
& producer's original intentions?


Previously, the only adjustment projectionists or techs had
up in the booth was Focus! And of course, scheduled
replacement of projector bulbs.

Apparently someone is personally offended when I mention
any extreme processing of image or audio here. Must have
a vested economic interest in extreme distortion of
image and audio for financial gain.

[Angus Kerr]

On Tuesday, September 29, 2015 at 11:18:04 AM UTC+2, Trevor wrote:
-snip-
the diode. I am so glad I can google these days which the cathode is,
because, even with the historical explanation, I've got a 50/50
chance of getting it wrong.

When I did EE 40 years ago we learned both conventional and electron
flow. Far from 50/50 chance of getting it wrong, I could always work
either way.
I meant being able to identify which terminal is the anode and which is the cathode.

As for the diode symbol, I just assume an arrow for conventional, or an
old fashioned blunderbuss for electron flow. :-)

I like that...
In any case how hard is it to understand electron flow is simply the
reverse of conventional flow? And if you know which flows +to- and which
-to+, the rest simply follows. Since neither is an exact representation
of what is really happening, it hardly matters which you choose IMO.

As far as conventional / electron current flow is concerned, it is a convention, after all. It just seems that if you think conventional, things kind of make sense, the symbols seem to be intuitive, and if you think electrons, you're pretty much swimming upstream.


Trevor.

-Angus.

[geoff]

On 29/09/2015 22:17, Trevor wrote:


When I did EE 40 years ago we learned both conventional and electron
flow. Far from 50/50 chance of getting it wrong, I could always work
either way.
As for the diode symbol, I just assume an arrow for conventional, or an
old fashioned blunderbuss for electron flow. :-)
In any case how hard is it to understand electron flow is simply the
reverse of conventional flow? And if you know which flows +to- and which
-to+, the rest simply follows. Since neither is an exact representation
of what is really happening, it hardly matters which you choose IMO.

It only matters if you are doing semiconductor physics. Else anything
other that 'conventional' is an irrelevant distraction.

geoff