To replace a wire which broke in the swivel
of the boom, I reconstructed the boom of an
Altec Lansing headset. This included
resoldering the wires to the back of the
electret capsule. The speakers still work
but the mic does not after this repair.

Found a similar failure after soldering a
new electret onto the wires of an inexpensive
Creative/Telex desktop mic.

Is the electret mic particularly heat sensitive?
If so, what technique is recommended? Already
I was careful to apply minimal heating.

Thanks, ... Peter Easthope

"Peter" wrote in message
...
To replace a wire which broke in the swivel
of the boom, I reconstructed the boom of an
Altec Lansing headset. This included
resoldering the wires to the back of the
electret capsule. The speakers still work
but the mic does not after this repair.

Found a similar failure after soldering a
new electret onto the wires of an inexpensive
Creative/Telex desktop mic.

Is the electret mic particularly heat sensitive?
If so, what technique is recommended? Already
I was careful to apply minimal heating.

Thanks, ... Peter Easthope



I've never found them to be particularly heat sensitive within common sense
limits, but note that they are polarity sensitive, as they contain a FET
preamp which is phantom powered via the output terminal ...

Arfa

In article ,
Arfa Daily wrote:
I've never found them to be particularly heat sensitive within common
sense limits, but note that they are polarity sensitive, as they
contain a FET preamp which is phantom powered via the output terminal
...

A few electret mic are phantom powered but the majority use a form of AB
power for the capsule.

--
*Gun Control: Use both hands.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
I've never found them to be particularly heat sensitive within common
sense limits, but note that they are polarity sensitive, as they
contain a FET preamp which is phantom powered via the output terminal
...

A few electret mic are phantom powered but the majority use a form of AB
power for the capsule.

--
*Gun Control: Use both hands.

Dave Plowman London SW
To e-mail, change noise into sound.


I'm using the term "phantom powered" loosely Dave, in that the audio out is
floating on the DC in, because there are only two connections, one of which
is the FET drain terminal, the series DC 'feed' resistor therefore actually
being the drain load resistor. The other terminal (also the capsule case) is
of course ground or FET source. Where there is this type of power / signal
setup, it is often considered generically, to be 'phantom powered' ...
Excuse my ignorance, but what's "AB power" ?

Arfa

In article ,
Arfa Daily wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
I've never found them to be particularly heat sensitive within common
sense limits, but note that they are polarity sensitive, as they
contain a FET preamp which is phantom powered via the output terminal
...

A few electret mic are phantom powered but the majority use a form of
AB power for the capsule.


I'm using the term "phantom powered" loosely Dave, in that the audio out
is floating on the DC in, because there are only two connections, one
of which is the FET drain terminal, the series DC 'feed' resistor
therefore actually being the drain load resistor. The other terminal
(also the capsule case) is of course ground or FET source. Where there
is this type of power / signal setup, it is often considered
generically, to be 'phantom powered' ... Excuse my ignorance, but
what's "AB power" ?

Not a good idea to use it where mics are concerned, though. Can cause
confusion.

Other thing is not all electrets have the same ground polarity. But
hopefully are marked.

AB or T power is where the DC is fed up the audio pair on a balanced mic.
Dates from before true phantom and has the disadvantage it puts DC across
a moving coil mic - although when it was common many used a PS for each
mic, rather than getting it from the mixer.
Arfa

--
*Age is a very high price to pay for maturity.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Meat Plow wrote:
http://richardhess.com/notes/2009/03...wering-schema/

Scroll down to A-B or T power.

I've never run across any T power mics or adaptors in my 35 years of
being around the equipment.

Only really used on some older top end mics. Mainly Sennheiser. Favoured
by outside broadcast types as it's more robust over long runs than
phantom.

Certainly still commonly in use 35 years ago in broadcasting. But some
mics that could use it also had an internal battery as an option.

Phantom to T power adaptors are the spawn of the devil. ;-)

--
*Why does the sun lighten our hair, but darken our skin?

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Meat Plow wrote:
I've never seen T powered and I run a music studio that has some
pricey vocal mics. Must be a broadcast studio/remote site favorite as
you mention.

They pre-date phantom mics - and good quality mics have a long, long life.

But they may well have been originally designed for location drama etc -
where they could get the power from a Nagra.

Would you know what makes them more robust? Can't be just the fact
that they run on 12 volts rather than 48.

Plenty of theories but can't be definite. Perhaps the fact they will
always work if the audio pair is ok - unlike phantom which needs the
screen. So one less pin/cable to go wrong. Perhaps a lower impedance
supply?

I suppose the voltage is an advantage for remote use requiring less
batteries or a more standard available source.

You still see new pro equipment with phantom and T power switchable - the
ubiquitous SQN, for one

--
*If you tell the truth, you don't have to remember anything.*

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
I've never found them to be particularly heat sensitive within common
sense limits, but note that they are polarity sensitive, as they
contain a FET preamp which is phantom powered via the output terminal
...

A few electret mic are phantom powered but the majority use a form of
AB power for the capsule.


I'm using the term "phantom powered" loosely Dave, in that the audio out
is floating on the DC in, because there are only two connections, one
of which is the FET drain terminal, the series DC 'feed' resistor
therefore actually being the drain load resistor. The other terminal
(also the capsule case) is of course ground or FET source. Where there
is this type of power / signal setup, it is often considered
generically, to be 'phantom powered' ... Excuse my ignorance, but
what's "AB power" ?

Not a good idea to use it where mics are concerned, though. Can cause
confusion.

Other thing is not all electrets have the same ground polarity. But
hopefully are marked.

AB or T power is where the DC is fed up the audio pair on a balanced mic.
Dates from before true phantom and has the disadvantage it puts DC across
a moving coil mic - although when it was common many used a PS for each
mic, rather than getting it from the mixer.


OK, but seems that all of this is tending to look at 'whole' mics as in
something that a newsreader would clip to himself, whereas the original
poster was talking about just the capsule inside, which was also what I was
referring to. As far as the polarity of electret mics varying, I can't
remember ever seeing a capsule where the case wasn't a negative-side ground,
and over the years, I have dealt with and replaced many in cordless phones
and similar.

I appreciate that to a sound engineer, the term "phantom power" has a
slightly special meaning in terms of voltage level etc, but that still
doesn't change the fact that generically, any system where DC power is
supplied to an active signal source, using only the wires that are carrying
the signal rather than any additional power carrying wire, are considered to
be 'phantom' powered, irrespective of the voltage involved. TV antenna
amplifiers for instance, are often described as being phantom powered, as
also are satellite LNBs.

However, all that said, I do take your point that it could give rise to
confusion between a sound engineer reading it, and an electronics engineer,
who might better understand the overall concept. Perhaps it would be better
to call the electret capsule 'line powered' ...

Arfa

In article ,
Arfa Daily wrote:
However, all that said, I do take your point that it could give rise to
confusion between a sound engineer reading it, and an electronics
engineer, who might better understand the overall concept. Perhaps it
would be better to call the electret capsule 'line powered' ...

Indeed - that's always how aerial pre-amps etc which use this technique
are described. At least in my experience.

Phantom power is so called because it is invisible to the actual required
signal. Line power doesn't qualify in this way.

--
*Microsoft broke Volkswagen's record: They only made 21.4 million bugs.

Dave Plowman London SW
To e-mail, change noise into sound.

On Thu, 9 April 16:42, Arfa Daily wrote:


"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
I've never found them to be particularly heat sensitive
within common sense limits, but note that they are polarity
sensitive, as they contain a FET preamp which is phantom
powered via the output terminal ...

A few electret mic are phantom powered but the majority use a
form of AB power for the capsule.


I'm using the term "phantom powered" loosely Dave, in that the
audio out is floating on the DC in, because there are only two
connections, one of which is the FET drain terminal, the
series DC 'feed' resistor therefore actually being the drain
load resistor. The other terminal (also the capsule case) is
of course ground or FET source. Where there is this type of
power / signal setup, it is often considered generically, to
be 'phantom powered' ... Excuse my ignorance, but what's "AB
power" ?

Arfa

Makes sense to me. Unfortunately the term Phantom Powered can be
used too loosely and gets misinterpreted.

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
However, all that said, I do take your point that it could give rise to
confusion between a sound engineer reading it, and an electronics
engineer, who might better understand the overall concept. Perhaps it
would be better to call the electret capsule 'line powered' ...

Indeed - that's always how aerial pre-amps etc which use this technique
are described. At least in my experience.


No Dave, they aren't. The term "phantom power" is used for many situations
where an active device needs powering and only the signal cable is
available. Antenna amplifiers, satellite LNBs, cable operators' distribution
amplifiers and so on, are all routinely described as being "phantom
powered". There are plenty of web references to the technique of phantom
powering in these applications. Long ago, when I worked in the early days of
cable TV, all of our line amplifiers were powered in this way, and it was
always referred to as phantom powering, both by all of the high-end network
engineering bods, and also our in-house lecturers, responsible for training
of all of the company's engineers.

In fact I would go as far as to say that the technique has been around and
called that for a very long time, and the 'hi-jacking' of the term by sound
engineering to try to mean something very specific, is actually the
questionable use of the phrase.



Phantom power is so called because it is invisible to the actual required
signal. Line power doesn't qualify in this way.


How so ? What do you perceive as being the difference ? If DC is travelling
one way, and signal the other on a single cable, they must be mutually
invisible (or made so by appropriate circuitry techniques at the active
device, and what it's feeding at the far end of its cable). I have never
seen any distinction made before. As far as I am aware, "Line powered" is
just a slightly more technically descriptive way of expressing "phantom
power".

Arfa

In article ,
Arfa Daily wrote:
No Dave, they aren't. The term "phantom power" is used for many
situations where an active device needs powering and only the signal
cable is available. Antenna amplifiers, satellite LNBs, cable
operators' distribution amplifiers and so on, are all routinely
described as being "phantom powered". There are plenty of web
references to the technique of phantom powering in these applications.
Long ago, when I worked in the early days of cable TV, all of our line
amplifiers were powered in this way, and it was always referred to as
phantom powering, both by all of the high-end network engineering bods,
and also our in-house lecturers, responsible for training of all of the
company's engineers.

In fact I would go as far as to say that the technique has been around
and called that for a very long time, and the 'hi-jacking' of the term
by sound engineering to try to mean something very specific, is
actually the questionable use of the phrase.

Phantom powering was first used by the telephone industry long before TV
of any sort. If the cable TV industry - hardly a bastion of good practice
- hijacked it for something which is patently not phantom, they're the
ones that are wrong.

--
*The closest I ever got to a 4.0 in school was my blood alcohol content*

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

In article ,
Arfa Daily wrote:
No Dave, they aren't. The term "phantom power" is used for many
situations where an active device needs powering and only the signal
cable is available. Antenna amplifiers, satellite LNBs, cable
operators' distribution amplifiers and so on, are all routinely
described as being "phantom powered". There are plenty of web
references to the technique of phantom powering in these applications.
Long ago, when I worked in the early days of cable TV, all of our line
amplifiers were powered in this way, and it was always referred to as
phantom powering, both by all of the high-end network engineering bods,
and also our in-house lecturers, responsible for training of all of the
company's engineers.

In fact I would go as far as to say that the technique has been around
and called that for a very long time, and the 'hi-jacking' of the term
by sound engineering to try to mean something very specific, is
actually the questionable use of the phrase.

Phantom powering was first used by the telephone industry long before TV
of any sort. If the cable TV industry - hardly a bastion of good practice
- hijacked it for something which is patently not phantom, they're the
ones that are wrong.


The telephone system was based on the same battery powered model the
early telegraph lines used. In fact, the early hand crank phones used a
local dry cell battery to power the line to the operator's switchboard.
Then there were the 20 and 60 mA teletype circuits where the power to
drive the mechanical decoder was remote powered over the data lines. It
is an obvious technology, being used by quite a few fields. As usual,
some group wants to claim to be the 'One true prophet' for their phony
religion.

--
And another motherboard bites the dust!

In article ,
Michael A. Terrell wrote:
Phantom powering was first used by the telephone industry long before
TV of any sort. If the cable TV industry - hardly a bastion of good
practice - hijacked it for something which is patently not phantom,
they're the ones that are wrong.


The telephone system was based on the same battery powered model the
early telegraph lines used. In fact, the early hand crank phones used a
local dry cell battery to power the line to the operator's switchboard.
Then there were the 20 and 60 mA teletype circuits where the power to
drive the mechanical decoder was remote powered over the data lines. It
is an obvious technology, being used by quite a few fields. As usual,
some group wants to claim to be the 'One true prophet' for their phony
religion.

Indeed - and the pro audio lot certainly didn't use the name 'phantom' for
the first line powered mics. That was called AB or T power.

--
*Keep honking...I'm reloading.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
Phantom powering was first used by the telephone industry long before
TV of any sort. If the cable TV industry - hardly a bastion of good
practice - hijacked it for something which is patently not phantom,
they're the ones that are wrong.

The telephone system was based on the same battery powered model the
early telegraph lines used. In fact, the early hand crank phones used a
local dry cell battery to power the line to the operator's switchboard.
Then there were the 20 and 60 mA teletype circuits where the power to
drive the mechanical decoder was remote powered over the data lines. It
is an obvious technology, being used by quite a few fields. As usual,
some group wants to claim to be the 'One true prophet' for their phony
religion.

Indeed - and the pro audio lot certainly didn't use the name 'phantom' for
the first line powered mics. That was called AB or T power.


Ever seen a phantom phone line? If anyone has the right to claim the
name, it is Western Electric.

--
And another motherboard bites the dust!

Arfa wrote, "... they are polarity sensitive, as they
contain a FET preamp ..."

On the Altec, I had the polarity wrong. Should have
trusted the mark I applied before removing the wires.

The headset works as well as ever now.

In this poor picture, the original capsule from the
Creative/Telex desktop mic is on the left.

http://carnot.yi.org/Mics.jpg

The replacement, on the right, has no silver
trace from a solder pad to the capsule. Half of
the head of the capsule is a brown Bakelite color
typical of a PCB. The other half is black. Is that a
conductive layer to connect one pad to the capsule?

In any case, I can buy another mic and try again.

Thanks everyone for the help, ... Peter E.

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
No Dave, they aren't. The term "phantom power" is used for many
situations where an active device needs powering and only the signal
cable is available. Antenna amplifiers, satellite LNBs, cable
operators' distribution amplifiers and so on, are all routinely
described as being "phantom powered". There are plenty of web
references to the technique of phantom powering in these applications.
Long ago, when I worked in the early days of cable TV, all of our line
amplifiers were powered in this way, and it was always referred to as
phantom powering, both by all of the high-end network engineering bods,
and also our in-house lecturers, responsible for training of all of the
company's engineers.

In fact I would go as far as to say that the technique has been around
and called that for a very long time, and the 'hi-jacking' of the term
by sound engineering to try to mean something very specific, is
actually the questionable use of the phrase.

Phantom powering was first used by the telephone industry long before TV
of any sort. If the cable TV industry - hardly a bastion of good practice
- hijacked it for something which is patently not phantom, they're the
ones that are wrong.


This is getting out of hand, and you seem to be being deliberately obtuse,
as you sometimes are about some subjects that seem to release a swarm of
bees in your bonnet. It was you who suggested that the term "phantom
powered" had some particular meaning, specifically with regard to
microphones, and that it shouldn't be used in other contexts. I never
particularly suggested that it was a term 'belonging' to the TV industry, or
indeed any other industry. As a sound engineer, I'm sure that you believe
that it has this specific meaning in the context of microphones only, but
that isn't so.

It is a general purpose term that describes the feeding of DC power to any
active device, using only the signal pair from that device. The telephone
people may well be the original users of the technique, and coiners of the
name "phantom power" for it, but it is just as valid to use the term for any
similar system, including microphone powering, and various items that I
happened to pick from the TV business.

And I'm still not clear what distinction in technique that you believe there
to be, between 'phantom powering' and 'line powering' ? Why do you believe
the powering scheme that they are using for their line amplifiers to be
"patently not phantom" ?

If you don't believe me that the manufacturers of TV distribution equipment
consider that what they are doing is employing 'phantom powering', then take
a look at for example

http://www.lashen.com/vendors/channe...VT-RF-Amps.asp

And why do you believe the cable TV industry to be "hardly a bastion of good
practice"? What is it you feel that they do wrong, or could do better ?

Arfa

In article ,
Michael A. Terrell wrote:
Indeed - and the pro audio lot certainly didn't use the name 'phantom'
for the first line powered mics. That was called AB or T power.


Ever seen a phantom phone line? If anyone has the right to claim the
name, it is Western Electric.

A phantom circuit is a different thing. Usually only used in desperation
as the quality isn't as good as the discrete pairs. Other problems with it
too.
Did Western Electric invent it?

--
*Confession is good for the soul, but bad for your career.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Arfa Daily wrote:
Phantom powering was first used by the telephone industry long before
TV of any sort. If the cable TV industry - hardly a bastion of good
practice - hijacked it for something which is patently not phantom,
they're the ones that are wrong.


This is getting out of hand, and you seem to be being deliberately
obtuse, as you sometimes are about some subjects that seem to release a
swarm of bees in your bonnet.

Pot, kettle.

It was you who suggested that the term
"phantom powered" had some particular meaning, specifically with regard
to microphones, and that it shouldn't be used in other contexts. I
never particularly suggested that it was a term 'belonging' to the TV
industry, or indeed any other industry. As a sound engineer, I'm sure
that you believe that it has this specific meaning in the context of
microphones only, but that isn't so.

Fine. Let's call apples oranges. Makes sense in your world.

It is a general purpose term that describes the feeding of DC power to
any active device, using only the signal pair from that device.

That is called line powering. Says what it is with no doubt. Why would you
want to call it anything else?

The telephone people may well be the original users of the technique,
and coiners of the name "phantom power" for it, but it is just as valid
to use the term for any similar system, including microphone powering,
and various items that I happened to pick from the TV business.

No it's not. It is a specific way of line powering.

And I'm still not clear what distinction in technique that you believe
there to be, between 'phantom powering' and 'line powering' ? Why do
you believe the powering scheme that they are using for their line
amplifiers to be "patently not phantom" ?

You don't know the difference?

I'll explain again, then. Line powering applies volts to anything on that
signal line. Phantom power doesn't - only to those devices configured to
use it. It also only applies to balanced circuits. So it follows the
meaning of phantom - invisible to some. Connect a DC meter to line power
and you'll see it. You won't with phantom.

If you don't believe me that the manufacturers of TV distribution
equipment consider that what they are doing is employing 'phantom
powering', then take a look at for example

http://www.lashen.com/vendors/channe...VT-RF-Amps.asp

'Phantom powered via a Power Injector'

If that's your example of a concise technical spec gawd help us.

And why do you believe the cable TV industry to be "hardly a bastion of
good practice"? What is it you feel that they do wrong, or could do
better ?

Perhaps I'm old enough to remember the appalling quality of those early
systems. And some of the newer ones too.

--
*Forget about World Peace...Visualize using your turn signal.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
Phantom powering was first used by the telephone industry long before
TV of any sort. If the cable TV industry - hardly a bastion of good
practice - hijacked it for something which is patently not phantom,
they're the ones that are wrong.


This is getting out of hand, and you seem to be being deliberately
obtuse, as you sometimes are about some subjects that seem to release a
swarm of bees in your bonnet.

Pot, kettle.

It was you who suggested that the term
"phantom powered" had some particular meaning, specifically with regard
to microphones, and that it shouldn't be used in other contexts. I
never particularly suggested that it was a term 'belonging' to the TV
industry, or indeed any other industry. As a sound engineer, I'm sure
that you believe that it has this specific meaning in the context of
microphones only, but that isn't so.

Fine. Let's call apples oranges. Makes sense in your world.

It is a general purpose term that describes the feeding of DC power to
any active device, using only the signal pair from that device.

That is called line powering. Says what it is with no doubt. Why would you
want to call it anything else?

The telephone people may well be the original users of the technique,
and coiners of the name "phantom power" for it, but it is just as valid
to use the term for any similar system, including microphone powering,
and various items that I happened to pick from the TV business.

No it's not. It is a specific way of line powering.

And I'm still not clear what distinction in technique that you believe
there to be, between 'phantom powering' and 'line powering' ? Why do
you believe the powering scheme that they are using for their line
amplifiers to be "patently not phantom" ?

You don't know the difference?

I'll explain again, then. Line powering applies volts to anything on that
signal line. Phantom power doesn't - only to those devices configured to
use it. It also only applies to balanced circuits. So it follows the
meaning of phantom - invisible to some. Connect a DC meter to line power
and you'll see it. You won't with phantom.

If you don't believe me that the manufacturers of TV distribution
equipment consider that what they are doing is employing 'phantom
powering', then take a look at for example

http://www.lashen.com/vendors/channe...VT-RF-Amps.asp

'Phantom powered via a Power Injector'

If that's your example of a concise technical spec gawd help us.

And why do you believe the cable TV industry to be "hardly a bastion of
good practice"? What is it you feel that they do wrong, or could do
better ?

Perhaps I'm old enough to remember the appalling quality of those early
systems. And some of the newer ones too.

--
*Forget about World Peace...Visualize using your turn signal.

Dave Plowman London SW
To e-mail, change noise into sound.

Whoosh

Arfa

In article ,
Arfa Daily wrote:
Whoosh

Ah. Another term you don't understand.

--
*There are two sides to every divorce: Yours and **** head's*

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:

In article ,
Michael A. Terrell wrote:
Indeed - and the pro audio lot certainly didn't use the name 'phantom'
for the first line powered mics. That was called AB or T power.


Ever seen a phantom phone line? If anyone has the right to claim the
name, it is Western Electric.

A phantom circuit is a different thing. Usually only used in desperation
as the quality isn't as good as the discrete pairs.

If the lines were designed to be phantomed, as many long-distance
telephone circuits were, the phantom should meet the same spec as the
main pairs.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

Adrian Tuddenham wrote:

Dave Plowman (News) wrote:

In article ,
Michael A. Terrell wrote:
Indeed - and the pro audio lot certainly didn't use the name 'phantom'
for the first line powered mics. That was called AB or T power.


Ever seen a phantom phone line? If anyone has the right to claim the
name, it is Western Electric.

A phantom circuit is a different thing. Usually only used in desperation
as the quality isn't as good as the discrete pairs.

If the lines were designed to be phantomed, as many long-distance
telephone circuits were, the phantom should meet the same spec as the
main pairs.


They did. The quality didn't suffer, until there were multiple
layers of phantom circuits. Some places used so many phantom circuits
in downtown areas that a problem on a single pair would affect dozens of
circuits. They were quite common in the days when each phone line was a
pair of single wires run between poles. They quickly ran out of room
for more pairs, and had to be creative until multiple pair lead sheathed
cable was developed.


--
And another motherboard bites the dust!

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
Indeed - and the pro audio lot certainly didn't use the name 'phantom'
for the first line powered mics. That was called AB or T power.

Ever seen a phantom phone line? If anyone has the right to claim the
name, it is Western Electric.

A phantom circuit is a different thing. Usually only used in desperation
as the quality isn't as good as the discrete pairs. Other problems with it
too.


Have you ever used a real WE designed phantom phone line? The quality
was only dependent on the frequency response of the special phantom
transformers, and how good the support pairs were. Properly installed,
you couldn't tell the difference. If you phantomed already bad pairs,
you got the noise and hum from both bad pairs.

Desperation? How about: "It was developed to provide telephone
service where it was impossible to run new lines."


Have you ever used 100 miles of old telephone trunkline for a network
feed at a remote radio station? Or, in a pinch, connected a spare audio
console directly to a phone line to do and emergency live remote feed to
the station?


Did Western Electric invent it?


Who do you think invented it?


--
And another motherboard bites the dust!

Arfa Daily wrote:

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
Phantom powering was first used by the telephone industry long before
TV of any sort. If the cable TV industry - hardly a bastion of good
practice - hijacked it for something which is patently not phantom,
they're the ones that are wrong.


This is getting out of hand, and you seem to be being deliberately
obtuse, as you sometimes are about some subjects that seem to release a
swarm of bees in your bonnet.

Pot, kettle.

It was you who suggested that the term
"phantom powered" had some particular meaning, specifically with regard
to microphones, and that it shouldn't be used in other contexts. I
never particularly suggested that it was a term 'belonging' to the TV
industry, or indeed any other industry. As a sound engineer, I'm sure
that you believe that it has this specific meaning in the context of
microphones only, but that isn't so.

Fine. Let's call apples oranges. Makes sense in your world.

It is a general purpose term that describes the feeding of DC power to
any active device, using only the signal pair from that device.

That is called line powering. Says what it is with no doubt. Why would you
want to call it anything else?

The telephone people may well be the original users of the technique,
and coiners of the name "phantom power" for it, but it is just as valid
to use the term for any similar system, including microphone powering,
and various items that I happened to pick from the TV business.

No it's not. It is a specific way of line powering.

And I'm still not clear what distinction in technique that you believe
there to be, between 'phantom powering' and 'line powering' ? Why do
you believe the powering scheme that they are using for their line
amplifiers to be "patently not phantom" ?

You don't know the difference?

I'll explain again, then. Line powering applies volts to anything on that
signal line. Phantom power doesn't - only to those devices configured to
use it. It also only applies to balanced circuits. So it follows the
meaning of phantom - invisible to some. Connect a DC meter to line power
and you'll see it. You won't with phantom.

If you don't believe me that the manufacturers of TV distribution
equipment consider that what they are doing is employing 'phantom
powering', then take a look at for example

http://www.lashen.com/vendors/channe...VT-RF-Amps.asp

'Phantom powered via a Power Injector'

If that's your example of a concise technical spec gawd help us.

And why do you believe the cable TV industry to be "hardly a bastion of
good practice"? What is it you feel that they do wrong, or could do
better ?

Perhaps I'm old enough to remember the appalling quality of those early
systems. And some of the newer ones too.

--
*Forget about World Peace...Visualize using your turn signal.

Dave Plowman London SW
To e-mail, change noise into sound.

Whoosh

Arfa


Definately. Early CATV systems required AC power at each pole
mounted 12 channel amplifer. I'll bet he believes all the hype about
'Monster Cable' too.


--
And another motherboard bites the dust!

"Dave Plowman (News)" wrote:

In article ,
Arfa Daily wrote:
Whoosh

Ah. Another term you don't understand.


You could fill a dozen phone books with terms you don't understand.

Explain: :Long Loop Video Combiner".


--
And another motherboard bites the dust!

Michael A. Terrell wrote:

Adrian Tuddenham wrote:

Dave Plowman (News) wrote:

In article ,
Michael A. Terrell wrote:
Indeed - and the pro audio lot certainly didn't use the name 'phantom'
for the first line powered mics. That was called AB or T power.


Ever seen a phantom phone line? If anyone has the right to claim the
name, it is Western Electric.

A phantom circuit is a different thing. Usually only used in desperation
as the quality isn't as good as the discrete pairs.

If the lines were designed to be phantomed, as many long-distance
telephone circuits were, the phantom should meet the same spec as the
main pairs.


They did. The quality didn't suffer, until there were multiple
layers of phantom circuits. Some places used so many phantom circuits
in downtown areas that a problem on a single pair would affect dozens of
circuits. They were quite common in the days when each phone line was a
pair of single wires run between poles. They quickly ran out of room
for more pairs, and had to be creative until multiple pair lead sheathed
cable was developed.

As a slightly quirky aside: starquad cable uses the 'phantom' for the
main circuit with the side pairs short-circuited. The 'phantom' in this
particular case gives better immunity to localised inteference than the
side pairs would on their own.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

In article ,
Michael A. Terrell wrote:

Adrian Tuddenham wrote:

Dave Plowman (News) wrote:

In article ,
Michael A. Terrell wrote:
Indeed - and the pro audio lot certainly didn't use the name
'phantom' for the first line powered mics. That was called AB or
T power.


Ever seen a phantom phone line? If anyone has the right to
claim the name, it is Western Electric.

A phantom circuit is a different thing. Usually only used in
desperation as the quality isn't as good as the discrete pairs.

If the lines were designed to be phantomed, as many long-distance
telephone circuits were, the phantom should meet the same spec as the
main pairs.


They did. The quality didn't suffer, until there were multiple
layers of phantom circuits. Some places used so many phantom circuits
in downtown areas that a problem on a single pair would affect dozens of
circuits. They were quite common in the days when each phone line was a
pair of single wires run between poles. They quickly ran out of room
for more pairs, and had to be creative until multiple pair lead sheathed
cable was developed.

I must admit I was thinking of where a telephone line is used as a 'music'
circuit for broadcast. A phantom one wasn't capable of the same
performance. But might well have been near identical at the sorts of
frequencies a telephone needs.

I doubt you'd get your broadband feed through one. ;_)

--
*Succeed, in spite of management *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Michael A. Terrell wrote:

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
Indeed - and the pro audio lot certainly didn't use the name
'phantom' for the first line powered mics. That was called AB or T
power.

Ever seen a phantom phone line? If anyone has the right to claim
the name, it is Western Electric.

A phantom circuit is a different thing. Usually only used in
desperation as the quality isn't as good as the discrete pairs. Other
problems with it too.


Have you ever used a real WE designed phantom phone line? The quality
was only dependent on the frequency response of the special phantom
transformers, and how good the support pairs were. Properly installed,
you couldn't tell the difference.

That goes against all I was taught. For sure they may have been adequate,
but in practice too many variables.

If you phantomed already bad pairs,
you got the noise and hum from both bad pairs.

Think you've answered your point...

Desperation? How about: "It was developed to provide telephone
service where it was impossible to run new lines."

It's never 'impossible' to run new lines. Otherwise none would ever be
installed. It was used as a stopgap until they were - I doubt you'd find
many in use today.


Have you ever used 100 miles of old telephone trunkline for a network
feed at a remote radio station? Or, in a pinch, connected a spare audio
console directly to a phone line to do and emergency live remote feed to
the station?

That really was what I was basing things on. A phantom music circuit never
performed as well as a discrete pair - even when that pair was an ordinary
telephone circuit.


Did Western Electric invent it?


Who do you think invented it?

I dunno. That's why I was asking you if you were sure or just guessing.
They may well have been the first to use them in the US, of course. But
that's not the same thing.

--
*Eagles may soar, but weasels don't get sucked into jet engines *

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Michael A. Terrell wrote:

"Dave Plowman (News)" wrote:

In article ,
Arfa Daily wrote:
Whoosh

Ah. Another term you don't understand.


You could fill a dozen phone books with terms you don't understand.

Explain: :Long Loop Video Combiner".

Whoosh.

--
*The severity of the itch is proportional to the reach *

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote in message
...
In article ,
Arfa Daily wrote:
Whoosh

Ah. Another term you don't understand.


Along with all the ones you don't then . I was implying that I was
contemplating sticking red hot needles in my eyes as a happier way of
spending my time than arguing with you, thus I was 'letting' it all whoosh
over my head ...

Arfa

"Dave Plowman (News)" wrote:

Michael A. Terrell wrote:

Have you ever used a real WE designed phantom phone line? The quality
was only dependent on the frequency response of the special phantom
transformers, and how good the support pairs were. Properly installed,
you couldn't tell the difference.

That goes against all I was taught. For sure they may have been adequate,
but in practice too many variables.

If you phantomed already bad pairs,
you got the noise and hum from both bad pairs.

Think you've answered your point...

Desperation? How about: "It was developed to provide telephone
service where it was impossible to run new lines."

It's never 'impossible' to run new lines. Otherwise none would ever be
installed. It was used as a stopgap until they were - I doubt you'd find
many in use today.


At one time it was. there are pictures of New York and other major
US cities with so many phone lines that the sidewalks were dark. They
literally ran out of room for new wire, under the original designs.
Some phantom circuits were only a few blocks, on pairs that went much
further. In some cases, the phantom circuit was cleaner than the other
pairs.


Have you ever used 100 miles of old telephone trunkline for a network
feed at a remote radio station? Or, in a pinch, connected a spare audio
console directly to a phone line to do and emergency live remote feed to
the station?

That really was what I was basing things on. A phantom music circuit never
performed as well as a discrete pair - even when that pair was an ordinary
telephone circuit.

Did Western Electric invent it?

Who do you think invented it?

I dunno. That's why I was asking you if you were sure or just guessing.
They may well have been the first to use them in the US, of course. But
that's not the same thing.


I saw several sets while in the US military. All were made by WE,
and had the parent numbers on them. WE wouldn't include the numbers if
they didn't own the patent.
--
*Eagles may soar, but weasels don't get sucked into jet engines *

Dave Plowman London SW
To e-mail, change noise into sound.


--
And another motherboard bites the dust!

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:

"Dave Plowman (News)" wrote:

In article ,
Arfa Daily wrote:
Whoosh

Ah. Another term you don't understand.

You could fill a dozen phone books with terms you don't understand.

Explain: :Long Loop Video Combiner".

Whoosh.


Is that British for 'I have no clue'?


--
And another motherboard bites the dust!

In article ,
Michael A. Terrell wrote:
Desperation? How about: "It was developed to provide telephone
service where it was impossible to run new lines."

It's never 'impossible' to run new lines. Otherwise none would ever be
installed. It was used as a stopgap until they were - I doubt you'd
find many in use today.


At one time it was. there are pictures of New York and other major
US cities with so many phone lines that the sidewalks were dark.

So that's still the case? Or did they find ways round this 'impossible'
situation? Like running multicores? And hopefully underground?

They literally ran out of room for new wire, under the original
designs. Some phantom circuits were only a few blocks, on pairs that
went much further.

In some cases, the phantom circuit was cleaner than
the other pairs.

I can quite see a phantom circuit being cleaner than a faulty copper pair.
However, try running that phantom circuit over faulty copper pairs...


Have you ever used 100 miles of old telephone trunkline for a
network feed at a remote radio station? Or, in a pinch, connected a
spare audio console directly to a phone line to do and emergency
live remote feed to the station?

That really was what I was basing things on. A phantom music circuit
never performed as well as a discrete pair - even when that pair was
an ordinary telephone circuit.

Did Western Electric invent it?

Who do you think invented it?

I dunno. That's why I was asking you if you were sure or just guessing.
They may well have been the first to use them in the US, of course. But
that's not the same thing.


I saw several sets while in the US military. All were made by WE,
and had the parent numbers on them. WE wouldn't include the numbers if
they didn't own the patent.

The equipment could well have been the subject of a patent. But did they
invent the principle? I did do a quick Google but got nowhere.

--
*Why is the third hand on the watch called a second hand?

Dave Plowman London SW
To e-mail, change noise into sound.

Arfa Daily wrote:


OK, but seems that all of this is tending to look at 'whole' mics as in
something that a newsreader would clip to himself, whereas the original
poster was talking about just the capsule inside, which was also what I was
referring to. As far as the polarity of electret mics varying, I can't
remember ever seeing a capsule where the case wasn't a negative-side ground,
and over the years, I have dealt with and replaced many in cordless phones
and similar.


IIRC the capsule in the Realistic (Tandy/RadioShack own brand) PZM
microphone had the +ve side connected to the case.

--
Tim Phipps

replace "invalid" with "uk" to reply by email

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
Desperation? How about: "It was developed to provide telephone
service where it was impossible to run new lines."

It's never 'impossible' to run new lines. Otherwise none would ever be
installed. It was used as a stopgap until they were - I doubt you'd
find many in use today.

At one time it was. there are pictures of New York and other major
US cities with so many phone lines that the sidewalks were dark.

So that's still the case? Or did they find ways round this 'impossible'
situation? Like running multicores? And hopefully underground?


Are you really that stupid? No new phantom circuits have been
installed in decades. As I said in other posts, the inability to run
more open pair circuits led to the development of lead jacketed multi
pair cable, which has mostly been replaced with Fiber optics. Phantom
telephone circuits were needed early last century, but technology has
passed them by. In areas where there is still copper to the CO, a newer
form of phantom is used, by multiplexing multiple lines to a single
pair. Typical audio grade is about 16 per pair. The technology wasn't
available in the early days of telephone.


They literally ran out of room for new wire, under the original
designs. Some phantom circuits were only a few blocks, on pairs that
went much further.

In some cases, the phantom circuit was cleaner than
the other pairs.

I can quite see a phantom circuit being cleaner than a faulty copper pair.
However, try running that phantom circuit over faulty copper pairs...


Which faults? How far away from the phantomed portion? Give me some
real numbers.


Have you ever used 100 miles of old telephone trunkline for a
network feed at a remote radio station? Or, in a pinch, connected a
spare audio console directly to a phone line to do and emergency
live remote feed to the station?

That really was what I was basing things on. A phantom music circuit
never performed as well as a discrete pair - even when that pair was
an ordinary telephone circuit.

Did Western Electric invent it?

Who do you think invented it?

I dunno. That's why I was asking you if you were sure or just guessing.
They may well have been the first to use them in the US, of course. But
that's not the same thing.

I saw several sets while in the US military. All were made by WE,
and had the parent numbers on them. WE wouldn't include the numbers if
they didn't own the patent.

The equipment could well have been the subject of a patent. But did they
invent the principle? I did do a quick Google but got nowhere.


WE listed their patent numbers on their products. I never saw
anything they built under a license to another company. WE was the
manufacturing arm of Bell Labs. I know you like to think that the US
stole every idea we ever had, but it just isn't true.


--
*Why is the third hand on the watch called a second hand?


To confuse stupid *******s. It works really well, doesn't it?



Dave Plowman London SW
To e-mail, change noise into sound.


--
And another motherboard bites the dust!

In article ,
Michael A. Terrell wrote:
In areas where there is still copper to the CO, a newer
form of phantom is used, by multiplexing multiple lines to a single
pair.

Crikey. How many other versions of 'phantom' are you going to use? Have
you ever written a technical spec?

--
*Middle age is when work is a lot less fun - and fun a lot more work.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
In areas where there is still copper to the CO, a newer
form of phantom is used, by multiplexing multiple lines to a single
pair.

Crikey. How many other versions of 'phantom' are you going to use? Have
you ever written a technical spec?


Yes, but you won't be allowed to read them, without the proper
security clearance.

--
And another motherboard bites the dust!

In article ,
Michael A. Terrell wrote:

"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
In areas where there is still copper to the CO, a newer
form of phantom is used, by multiplexing multiple lines to a single
pair.

Crikey. How many other versions of 'phantom' are you going to use? Have
you ever written a technical spec?


Yes, but you won't be allowed to read them, without the proper
security clearance.

Wasn't the one for the Challenger O rings, was it?

--
*Arkansas State Motto: Don't Ask, Don't Tell, Don't Laugh.

Dave Plowman London SW
To e-mail, change noise into sound.

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

"Dave Plowman (News)" wrote:

In article ,
Arfa Daily wrote:
Whoosh

Ah. Another term you don't understand.


You could fill a dozen phone books with terms you don't understand.

Explain: :Long Loop Video Combiner".


--
And another motherboard bites the dust!

Explain: Dirty Sanchez