Getting matching transformer from telephone

[Eeyore]

Archimedes' Lever wrote:

I do not recall giving it the moniker of "isolation transformer". I
merely mentioned the function of electrical isolation.

Which is NOT required.

Graham

 

[Eeyore]

Phil Allison wrote:

** God, you are one STUPID PIG IGNORANT PUKE !

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

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

...... Phil

You know Phil, there are times I really have to agree with you 101%.

Graham

 

[Eeyore]

krw wrote:

rabbitsfriendsandrelations@hotmail.com says...
"Michael A. Terrell" wrote:

and the equipment he designed is for sale on Ebay.

IT IS

You forgot; "A place that would shame Ali-baba & his 40 thieves",

I have found ebay to be an EXCELLENT place to shop. Many of the best
deals are to be had there. Why run a shop with overheads when you can do
it all online and they even provide the invoicing tools !

And I know shops who do have traditional outlets AND they sell on ebay
too, often at a lower cost. Saved someone several pounds exactly that
way recently in fact.

Graham

 

[Eeyore]

"Floyd L. Davidson" wrote:

What the phone is made of is not important in any way to this
conversation.

Really ?

Have you ever heard of conductors and non-conductors ?

Graham

 

[Eeyore]

"Floyd L. Davidson" wrote:

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

The fact that phones are made of plastic IS the damn reason that GALVANIC
isolation from the phone line is not required.

That is one of the best bits of humor I've seen in some time on
this group. Nice post. I was rolling on the floor laughing.

I'm laughing at YOU !

Have you NO understanding how phones work ? Apparently NOT ! Ringing voltage is
around 100V AC or chopped DC. How's your matching transformer going to deal with
THAT ?

Graham

 

[Eeyore]

Eeyore wrote:

"Floyd L. Davidson" wrote:

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

The fact that phones are made of plastic IS the damn reason that GALVANIC
isolation from the phone line is not required.

That is one of the best bits of humor I've seen in some time on
this group. Nice post. I was rolling on the floor laughing.

I'm laughing at YOU !

Have you NO understanding how phones work ? Apparently NOT ! Ringing voltage is
around 100V AC or chopped DC. How's your matching transformer going to deal with
THAT ?

http://en.wikipedia.org/wiki/Ringing_voltage#Ringing_signal

 

[tony sayer]

In article <495B6923.4C8C363D@hotmail.com>, Eeyore <rabbitsfriendsandrel
ations@hotmail.com> scribeth thus

Archimedes' Lever wrote:

Hey! Floyd doesn't have an attitude, and is pretty darned good at
accepting other standards and practices, once they are brought to his
attention. I am sure he will concur with you once he realizes from your
post, that the geography and era were different than that he had his
mindset in.

Unfortunately has has NO CLUE about the characteristic impedance of twisted pair
cable as used for telecoms.

http://en.wikipedia.org/wiki/Twisted_pair#Unshielded_twisted_pair_.28UTP.29

"UTP is also finding increasing use in video applications, primarily in security
cameras. Many middle to high-end cameras include a UTP output with setscrew
terminals. This is made possible by the fact that UTP cable bandwidth has
improved to match the baseband of television signals. While the video recorder
most likely still has unbalanced BNC connectors for standard coaxial cable, a
balun is used to convert from 100-ohm balanced UTP to 75-ohm unbalanced."

*** 100-ohm balanced UTP ***

Graham

I seem to remember from another time that Old Floyd worked for some
Alaskan phone company..

Anyways what was the original question .. seems to have fallen off the
news server?...
--
Tony Sayer

 

[tony sayer]

In article <495B6A2D.DB9F260A@hotmail.com>, Eeyore <rabbitsfriendsandrel
ations@hotmail.com> scribeth thus

"Floyd L. Davidson" wrote:

Stuart <Spambin@argonet.co.uk> wrote:
Floyd L. Davidson <floyd@apaflo.com> wrote:

(Years ago I worked on telegraph systems...)

Which has nothing to do with the information I am giving here.

It has everything to do with the information we are
discussing.

You don't know the difference between telegraph wire and
telephone wire, just for starters.

Quite so !


I have come across your attitude in other groups where americans don't
seem to understand that their way of doing things isn't universal
throughout the rest of the world. Also an inability to read other people's
posts and understand what is being said.

For example, you seem to have entirely missed:

In the UK these cables went underground from studio, via as many exchanges
and repeater stations as necessary, to transmitter and never overhead.
^^^^^^^^^^^^^^^^^^^^^

If that was in reference to the previous paragraph of
yours, then you should have put the information there.
In that case I would have jumped all over your claim
that it makes a difference for the 600 mile distance
mentioned when in fact it is not 600 miles *per* *section*.

You also apparently don't know what "repeater stations"
are when dealing with analog carrier systems.

Yes, we did send program feeds from London to Burghead in Scotland via
landline.

You sent them that distance via FDM carrier systems, not
via landlines, even in the 1930's.

Yes, although different impedences are *now* used under different
circumstances, the cables *were* /all/ 600 ohms twisted pair.

Twisted pair cables are not 600 Ohms.

Absolutely not. About 100 ohms.


Open wire might be though... ;-)

In more
recent times we've had rep-coils on the incoming lines to match to 150
ohms and 75 ohms but by and large all *main* feeds are now by digital
systems.

By and large? And 75 Ohms??? (Please don't try buzz words...)

GPO=General Post Office, the organisation in the UK originally responsible
for all telecommunications in the UK.

Thank you. (I'm familiar with BT, which evolved from
the General Post Office.)

Via 'Post Office Telecommunications'.


Your problem is that you just don't actually understand
the telephone system, at all.

He has made that evidently apparent.

Graham

Course there are misunderstandings and some terminology shift in
broadcast/telecoms and all related to the way various operators used to
and now do things etc at different times..

But its all good for a slanging match...
--
Tony Sayer

 

[Eeyore]

tony sayer wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> scribeth thus
Archimedes' Lever wrote:

Hey! Floyd doesn't have an attitude, and is pretty darned good at
accepting other standards and practices, once they are brought to his
attention. I am sure he will concur with you once he realizes from your
post, that the geography and era were different than that he had his
mindset in.

Unfortunately has has NO CLUE about the characteristic impedance of twisted pair
cable as used for telecoms.

http://en.wikipedia.org/wiki/Twisted_pair#Unshielded_twisted_pair_.28UTP.29

"UTP is also finding increasing use in video applications, primarily in security
cameras. Many middle to high-end cameras include a UTP output with setscrew
terminals. This is made possible by the fact that UTP cable bandwidth has
improved to match the baseband of television signals. While the video recorder
most likely still has unbalanced BNC connectors for standard coaxial cable, a
balun is used to convert from 100-ohm balanced UTP to 75-ohm unbalanced."

*** 100-ohm balanced UTP ***

I seem to remember from another time that Old Floyd worked for some
Alaskan phone company..

Anyways what was the original question .. seems to have fallen off the
news server?...

A slightly obscure question as to effectively (not sure if the OP realised) whether
impedance or voltage matching was important. Needless to say, many IDIOTS think
everything audio HAS to be 600 ohms which is an irrelevant ancient standard anyway
but lingers on in the minds of the long brain-dead.

Here's the original.

" I am looking for some 1-to-1 matching transformers to connect varioua
audio devices to my PC. I usually get noises and hum.

These line matching transformers are not so cheap at about Ł6 or 7
each.

Telephones seem to suppress line noise and hum rather well so I
figure the components they use are probably of half-decent quality.

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

Graham

 

[tony sayer]

In article <495BE9F9.6DEA2000@hotmail.com>, Eeyore <rabbitsfriendsandrel
ations@hotmail.com> scribeth thus

tony sayer wrote:

Eeyore <rabbitsfriendsandrelations@hotmail.com> scribeth thus
Archimedes' Lever wrote:

Hey! Floyd doesn't have an attitude, and is pretty darned good at
accepting other standards and practices, once they are brought to his
attention. I am sure he will concur with you once he realizes from your
post, that the geography and era were different than that he had his
mindset in.

Unfortunately has has NO CLUE about the characteristic impedance of twisted
pair
cable as used for telecoms.

http://en.wikipedia.org/wiki/Twisted_pair#Unshielded_twisted_pair_.28UTP.29

"UTP is also finding increasing use in video applications, primarily in
security
cameras. Many middle to high-end cameras include a UTP output with setscrew
terminals. This is made possible by the fact that UTP cable bandwidth has
improved to match the baseband of television signals. While the video
recorder
most likely still has unbalanced BNC connectors for standard coaxial cable, a
balun is used to convert from 100-ohm balanced UTP to 75-ohm unbalanced."

*** 100-ohm balanced UTP ***

I seem to remember from another time that Old Floyd worked for some
Alaskan phone company..

Anyways what was the original question .. seems to have fallen off the
news server?...

A slightly obscure question as to effectively (not sure if the OP realised)
whether
impedance or voltage matching was important. Needless to say, many IDIOTS think
everything audio HAS to be 600 ohms which is an irrelevant ancient standard
anyway
but lingers on in the minds of the long brain-dead.

Here's the original.

" I am looking for some 1-to-1 matching transformers to connect varioua
audio devices to my PC. I usually get noises and hum.

These line matching transformers are not so cheap at about Ł6 or 7
each.

Telephones seem to suppress line noise and hum rather well so I
figure the components they use are probably of half-decent quality.

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

Graham

Right..

Wonder what's he actually trying to do .. in practice?..

If he's still there?...
--
Tony Sayer

 

[Michael A. Terrell]

Eeyore wrote:

krw wrote:

rabbitsfriendsandrelations@hotmail.com says...
krw wrote:

Not much of a difference, eh?

What meds are YOU on ?

Metoprolol

US trade name.

Beta blocker ! Ticker problem ? Not surprised with your temper.

and aspirin why? Is your inferriority getting the better of you
again?

Mine are MUCH more exciting ! Hopefully the physio (suspected trapped
nerve) will remove the need for the opiates.

Going in for a CT on 14th Jan too btw. They're really giving me the
working over this time. And all for FREE on the National Health System !
You might learn something from that. Hillary's not wrong.

If the National Health System was any good you would be committed for
poor mental health.



--
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There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

 

[Michael A. Terrell]

Eeyore wrote:

"Michael A. Terrell" wrote:

Eeyore wrote:
"Michael A. Terrell" wrote:

Now, you are catching on. Eeyore is a british idiot

Your ignorance stands out like a shining beacon on a dark night.

There never was or has ever been a need for a transformer in a phone.

So much donkey arrogance, so little intelligence.

So, go on Mr Expert. Why is one *needed* ?

Do your own homework. I've already posted a link to the 2500 series
single line telephone schematic. If you are too stupid to read it,
that's your problems. The 'need' was discussed in this thread, but in
your typical ignorance you ignored it.



--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

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your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

 

[Michael A. Terrell]

Eeyore wrote:

"Michael A. Terrell" wrote:

Alexander Graham Bell despised optocouplers

He didn't have the opportunity, as they didn't exist in his lifetime.

History's never been your strong suit has it ?

Your ignorance is showing, as usual. That was the '50 plus year lead
time' was for it to be invented, dumbass.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.

 

[krw]

In article <495BE291.F05702B@hotmail.com>,
rabbitsfriendsandrelations@hotmail.com says...

krw wrote:

rabbitsfriendsandrelations@hotmail.com says...
krw wrote:

Not much of a difference, eh?

What meds are YOU on ?

Metoprolol

US trade name.

Beta blocker ! Ticker problem ? Not surprised with your temper.

A-fib. "Temper"? There is nothing here important enough to get
excited about, certainly not you.

and aspirin why? Is your inferriority getting the better of you
again?

Mine are MUCH more exciting ! Hopefully the physio (suspected trapped
nerve) will remove the need for the opiates.

A drugie, I suspected as much.

Going in for a CT on 14th Jan too btw. They're really giving me the
working over this time. And all for FREE on the National Health System !
You might learn something from that. Hillary's not wrong.

If you lived in the US you'd have had it done by now. CT scans
aren't something rare here. There is *nothing* free in this world.
You're simply taxed through the nose, to wait.

--
Keith

 

[krw]

In article <495BE321.34360172@hotmail.com>,
rabbitsfriendsandrelations@hotmail.com says...

"Michael A. Terrell" wrote:

Alexander Graham Bell despised optocouplers

He didn't have the opportunity, as they didn't exist in his lifetime.

History's never been your strong suit has it ?

Reading has never been your strong suit, eh Dumbass Donkey?

--
Keith

 

[krw]

In article <495BE67E.701087E3@hotmail.com>,
rabbitsfriendsandrelations@hotmail.com says...

krw wrote:

rabbitsfriendsandrelations@hotmail.com says...
"Michael A. Terrell" wrote:

and the equipment he designed is for sale on Ebay.

IT IS

You forgot; "A place that would shame Ali-baba & his 40 thieves",

I have found ebay to be an EXCELLENT place to shop. Many of the best
deals are to be had there. Why run a shop with overheads when you can do
it all online and they even provide the invoicing tools !

It is a good place for bottom feeders to congregate, sure.

And I know shops who do have traditional outlets AND they sell on ebay
too, often at a lower cost. Saved someone several pounds exactly that
way recently in fact.

No one said bottom feeders didn't have "traditional outlets".

--
Keith

 

[Franc Zabkar]

On 30 Dec 2008 11:54:01 +0200, Tomi Holger Engdahl
<then@pippuri.niksula.hut.fi> put finger to keyboard and composed:

In european specifications (for Finland etc..) I have seen this
that complex reference impedance Z = 270 + (750 //150 nF)

750 ohm
_____
270 ohm +--|_____|--+
_____ | |
--|_____|---+ +-----
| || |
+----||-----+
||
150 nF

I'd just like to contribute a couple of references which I found
useful in the past.

This [old] document talks about complex impedances (see page 37):
http://web.archive.org/web/20001001070243/http://www.midcom-inc.com/pdf/TN69.pdf

International Digital Access Arrangements:
http://groups.google.com/group/comp.dcom.modems/msg/232247c06425cc1d?dmode=source

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[daestrom]

krw wrote:

In article <oqydnaMeppa09cbUnZ2dnUVZ_gidnZ2d@earthlink.com>,
mike.terrell@earthlink.net says...

Eeyore wrote:

"Michael A. Terrell" wrote:

Now, you are catching on. Eeyore is a british idiot

Your ignorance stands out like a shining beacon on a dark night.

There never was or has ever been a need for a transformer in a
phone.


So much donkey arrogance, so little intelligence.

s/arrogance/dung/

Wouldn't the correct syntax be:

s/arrogance/dung/g

?? So it replaces more than one occurance on each line??

Sed, gotta love it

daestrom

 

[Salmon Egg]

In article <495BE43E.5270CF1E@hotmail.com>,
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

For a long time I believe the term actually used for this transformer
was "induction coil."

Now we're getting to the point.

'Loading coils' were used to boost voice levels on long line circuits by
loading the line to compensate for line capacitance IIRC.

NOT needed in your average city. And certainly NOT a *transformer*.

I was NOT referring to loading coils. I was referring to the
transformers inside telephones that impressed ac signals onto the pair
of conductrs forming the subscriber line.

Bill

--
Private Profit; Public Poop! Avoid collateral windfall!

 

[Salmon Egg]

In article <495BE78C.DB5CFA26@hotmail.com>,
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote:

Have you NO understanding how phones work ? Apparently NOT ! Ringing voltage
is
around 100V AC or chopped DC. How's your matching transformer going to deal
with
THAT ?

It does not have to. With the phone on hook, the ringing takes place in
a circuit that disappears when the phone goes off hook.

Bill

--
Private Profit; Public Poop! Avoid collateral windfall!