Getting matching transformer from telephone

[Phil Allison]

"Floyd FUCKING LIAR Davidson"

"Phil Allison"
"Stuart"

However, regardless of what you know or don't know, this thread was
started by someone who wanted to know whether he could re-use the
transformers in telephones for another purpose so clearly he has some!

** That is entirely false.

What the OP *actually asked* was this:

" If I strip down some landline phones I 've got here, then will there
be a matching transformer in each one? "

Chances are high there are no iron core transformers ( hybrid or other) in
his phones at all - cos they are too modern.

Secondly, his purpose requires a transformer with high voltage safety
isolation from the phone line - which the common 600:600 ohms phone line
types all have and others do not.

Thirdly, his purpose requires a transformer with very high CMRR - cos
that
is why he is getting humming noises at the moment when making recordings
with his passive ( ie non-transformer ) adaptor device.

Have you ever done this ??

I can assure you it ain't as simple as you suspect to get a hum free and
distortion free result.

BS. It is *very* simple. Every simple (or complex)
telephone for a hundred years or so has been doing the
exact same thing!

** Totally wrong comparison to the interfacing issue here.

FUCKWIT !!

Not the least of the problems is that portable voice recorders have high
sensitivity mic inputs with automatic gain control circuits - which cannot
be defeated by the user. This results in annoying gain pumping and
regular
bursts of overload distortion PLUS increasing background noise & hum
whenever there is a pause in the conversation.

And *you* don't know how to set levels properly to
handle that?

** The "level" control generally often comes post the AGC circuit -

YOU ASININE BULSHITTING FUCKWIT !!

The trick is to use just the right amount of resistive divider attenuation
before and after the 1:1 transformer to eliminate this - plus cap
couple
the input side to stop pulling the line low.

Why not use a properly designed pad, with the correct
impedance?

** Cos that will NOT have the required CMMR to eliminate all trace of hum
NOR be safe to use.

You LYING FUCKWIT !




...... Phil

 

[Eeyore]

"Floyd L. Davidson" wrote:

"Pulling the line low"???? Giggle snort,
cough and laugh...

A: OFF HOOK you twit.

B: the DC resistance of the transformer primary may cause the phone to stop
working by lowering the line voltage too much.

Graham

 

[Archimedes' Lever]

On Sat, 03 Jan 2009 04:47:05 +0000, Eeyore
<rabbitsfriendsandrelations@hotmail.com> wrote:

Archimedes' Lever wrote:

"Phil Allison" <philallison@tpg.com.au> wrote:

What the OP *actually asked* was this:

" If I strip down some landline phones I 've got here, then will there
be a matching transformer in each one? "

Which, to anyone with even half a brain, obviously means that he wishes
to utilize it as well, you stupid fucktard!

He can only utilise it if it contains one OBVIOUSLY !

Graham

That was not the argument, you retarded non-human dumbfuck.

The word is UTILIZE.

 

[Floyd L. Davidson]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

Ross Herbert wrote:

Since your PC is mains powered and it may not have the required isolation
between the mains side and the sound card input you can do your own thing using
an approved 600:600 transformer with 3kV isolation rating to interface the
telephone line to the sound card input.

He DOES NOT need a 600 ohm transformer since the input impedance of the sound card
is not 600 ohms <sigh> !

It's more likely to be in the tens of kilohms.

What he really wants is something like a 10k:10k 'line bridging' transformer.

Tell us about how different a 600:600 transformer is
from a 10k:10k transformer, eh?

In
practice, using a '600 ohm' transformer will probably be ok, but being incorrectly
loaded will degrade the sound quality (freq resonse may be peaky etc).

What he probably wants is a 1:1 transformer.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

 

[Eeyore]

"Floyd L. Davidson" wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
"Floyd L. Davidson" wrote:

Then just exactly how do you think the transmitter got
power in those old phones?

OLD (and no longer used) is all you seem to know about.

You falsely claimed it was otherwise. Seems *you* are
the one with a lack of "know" about this topic.

What ?

Look, I've designed line interfaces FFS. For Xerox. I've already
mentioned it once.

Graham

 

[Floyd L. Davidson]

"Michael A. Terrell" <mike.terrell@earthlink.net> wrote:

Eeyore wrote:

Ross Herbert wrote:

Since your PC is mains powered and it may not have the required isolation
between the mains side and the sound card input you can do your own thing using
an approved 600:600 transformer with 3kV isolation rating to interface the
telephone line to the sound card input.

He DOES NOT need a 600 ohm transformer since the input impedance of the sound card
is not 600 ohms <sigh> !

It's more likely to be in the tens of kilohms.

What he really wants is something like a 10k:10k 'line bridging' transformer. In
practice, using a '600 ohm' transformer will probably be ok, but being incorrectly
loaded will degrade the sound quality (freq resonse may be peaky etc).

An 'audio expert' would put a 600 ohm resistor across the secondary
to provide proper loading but no expects you to know that.

That would be true *if* he wanted to load the circuit
down to 600 Ohms, but he almost certainly does not.
Doing so would reduce the level available to the
telephone set user by 3 dB. What he probably wants to
do is bridge across the "600 Ohm" telephone set with
something that is at least 6000 Ohms.

If the line input this transformer is attached to is 6k
Ohms or higher, a 1:1 transformer will do. Otherwise he
has two choices, one of which is a transformer with a
more suitable turns ratio, which will provide maximum
signal level. However, at that point there is almost
certainly an excess of gain, and hence another possible
solution is to merely put a pair of resistors in series
with the side connecting to the telephone set, or on the
side of the transformer connecting to his recording
device (if it is single ended, it requires only a single
resistor).



--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

 

[Eeyore]

Stuart wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
High-fidelity Microphone

" Common uses include matching the relatively low 2K ohm output
impedance of a microphone to an amplifier’s much higher line input
impedance of 10K ohms. Studios commonly use the three terminal “XLR”
type of connector which is a balanced connection method with a terminal
for a center tap. A separate ground terminal, tied to the XLR
connector’s case is almost always present. The center tap may be used to
phantom-feed a small amount of current for powering a pre-amp or active
“condenser” microphone."

LMAO !

You mean you didn't know that either?

Ok, a typical dynamic microphone is often nearer 150-300 ohms output

Rather different to 2k I think you'll agree.

impedence and Ribbons can be as low as 50 Ohm but otherwise......

Ribbons are FAR lower. Maybe 50 ohms AFTER the transformer !

And Pin 1 on an XLR is ALWAYS the cable shield. It may also be GROUND - but
that's another story. It certainly isn't used to provide phantom power under
ANY circumstances. And the last time I came across a centre tapped transformer
in pro-audio was 35 years ago. It caused a bloody nuisance too. Modern
balanced audio circuits are 'floating'. The centre tap provides ZERO
advantage.

I now expect you to make an idiot of yourself trying to refute that one.

Graham

 

[Phil Allison]

"Floyd LYING FUCKWIT Davidson"

Tell us about how different a 600:600 transformer is
from a 10k:10k transformer, eh?

** Err -

could it be the optimum source and load impedances are 16.7 times higher in
the latter case ????

Nah - electronics is always much trickier than that .




...... Phil

 

[Phil Allison]

"Floyd LIAR Davidson"


** FUCK the HELL OFF

you know nothing BLOODY IDIOT !!!





..... Phil

 

[Phil Allison]

"Archimedes'= LUNATIC TROLL"


** Go DROP DEAD !!


you VILE TROLLING PIECE OF SHIT




.... Phil

 

[Archimedes' Lever]

On Sat, 3 Jan 2009 16:26:13 +1100, "Phil Allison"
<philallison@tpg.com.au> wrote:

"Archimedes'= LUNATIC TROLL"


** Go DROP DEAD !!


you VILE TROLLING PIECE OF SHIT




... Phil


Better than being the vile, sub-human piece of shit that you are, boy.

 

[Phil Allison]

"Archimedes'= LUNATIC TROLL"


** Go DROP DEAD !!


you VILE TROLLING PIECE OF AUTISTIC SHIT





.... Phil

 

[Floyd L. Davidson]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

"Floyd L. Davidson" wrote:

Not all telephone cable can run ADSL.

In civilised parts of the world with proper infrastructure it can.

How would you know that?

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

 

[Floyd L. Davidson]

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

"Floyd L. Davidson" wrote:

"Pulling the line low"???? Giggle snort,
cough and laugh...

A: OFF HOOK you twit.

Off hook is a loop *current* condition.

B: the DC resistance of the transformer primary may cause the phone to stop
working by lowering the line voltage too much.

Typically a split winding is used, with a mid-point
capacitor to block DC current.

Even you should have known that.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

 

[Eeyore]

Archimedes' Lever wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
"Floyd L. Davidson" wrote:

Not all telephone cable can run ADSL.

In civilised parts of the world with proper infrastructure it can.

In the right situation, someone might actually consider you as credible
too. Just not in the reality that we all live in. We call it the real
world. In it, you and credibility do not homogenize together. That is
one water your oily ass won't mix with.

You are DimBulb and I claim my Ł1000.

Graham

 

[Eeyore]

Archimedes' Lever wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
Archimedes' Lever wrote:
"Phil Allison" <philallison@tpg.com.au> wrote:

What the OP *actually asked* was this:

" If I strip down some landline phones I 've got here, then will there
be a matching transformer in each one? "

Which, to anyone with even half a brain, obviously means that he wishes
to utilize it as well, you stupid fucktard!

He can only utilise it if it contains one OBVIOUSLY !

That was not the argument, you retarded non-human dumbfuck.

The word is UTILIZE.

Not in the civilised world.

http://www.thinkscience.co.jp/toolshed/2008/10/british-vs-american-english-spelling/

Graham

 

[Eeyore]

"Floyd L. Davidson" wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

Tell us about how different a 600:600 transformer is
from a 10k:10k transformer, eh?

Have you even the tiniest clue yourself ?

Graham

 

[Floyd L. Davidson]

"Phil Allison" <philallison@tpg.com.au> wrote:

"Floyd FUCKING LIAR Davidson"

"Phil Allison"
"Stuart"

However, regardless of what you know or don't know, this thread was
started by someone who wanted to know whether he could re-use the
transformers in telephones for another purpose so clearly he has some!

** That is entirely false.

What the OP *actually asked* was this:

" If I strip down some landline phones I 've got here, then will there
be a matching transformer in each one? "

Chances are high there are no iron core transformers ( hybrid or other) in
his phones at all - cos they are too modern.

Secondly, his purpose requires a transformer with high voltage safety
isolation from the phone line - which the common 600:600 ohms phone line
types all have and others do not.

Thirdly, his purpose requires a transformer with very high CMRR - cos
that
is why he is getting humming noises at the moment when making recordings
with his passive ( ie non-transformer ) adaptor device.

Have you ever done this ??

I can assure you it ain't as simple as you suspect to get a hum free and
distortion free result.

BS. It is *very* simple. Every simple (or complex)
telephone for a hundred years or so has been doing the
exact same thing!

** Totally wrong comparison to the interfacing issue here.

FUCKWIT !!

It has worked for roughly 100 years, it's well known, it is simple.

Except, apparently, for you.

Not the least of the problems is that portable voice recorders have high
sensitivity mic inputs with automatic gain control circuits - which cannot
be defeated by the user. This results in annoying gain pumping and
regular
bursts of overload distortion PLUS increasing background noise & hum
whenever there is a pause in the conversation.

And *you* don't know how to set levels properly to
handle that?

** The "level" control generally often comes post the AGC circuit -

YOU ASININE BULSHITTING FUCKWIT !!

There is no "level control". I said, "to set
levels"... which is done by various means, such as
designing the right loss into pads, etc.

Please familiarize yourself with the terminology
commonly used to describe telecommunication equipment.

The trick is to use just the right amount of resistive divider attenuation
before and after the 1:1 transformer to eliminate this - plus cap
couple
the input side to stop pulling the line low.

Why not use a properly designed pad, with the correct
impedance?

** Cos that will NOT have the required CMMR to eliminate all trace of hum
NOR be safe to use.

You LYING FUCKWIT !

You have that backwards. If you use a properly designed
pad with the correct impedance it will maximized common
mode rejection of induced currents.

As far as to how using correctly designed pads are
unsafe, I'll pass on that one and let you explain what
you think you are saying. (Because I just can't imagine
how a proper pad, or even an improper one, is unsafe.)

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd@apaflo.com

 

[Eeyore]

Archimedes' Lever wrote:

"Phil Allison" <philallison@tpg.com.au> wrote:
"Archimedes'= LUNATIC TROLL"

** Go DROP DEAD !!

you VILE TROLLING PIECE OF SHIT

... Phil

Better than being the vile, sub-human piece of shit that you are, boy.

He does at least know what he's talking about, unlike you.

Graham

 

[Eeyore]

"Floyd L. Davidson" wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:
"Floyd L. Davidson" wrote:

Not all telephone cable can run ADSL.

In civilised parts of the world with proper infrastructure it can.

How would you know that?

Jesus Wept !

Graham