[John Byrns]

In article ,
Eeyore wrote:

John Byrns wrote:

Eeyore wrote:

Have you even the tiniest idea what a telegraph line looks like ?

Now it is back to open wire lines again, you really seem to have a thing
for open wire lines.

Because it's the only type of 'phone line' that has a characteristic
impedance of
600 ohms. And *I* don't have a thing for 600 ohms, *YOU* do !

You are the one that seems to be fixated on open wire lines and 600
Ohms, not me. If you go back to the beginning of the thread, you will
see that the first points I made were that the impedance of "standard
telephone line", a.k.a. 19 gauge toll cable, varies with frequency
across the audio band. I also pointed out more than once that when
being used for Hi-Fi audio transmission, this cable should be terminated
in 150 Ohms not 600 Ohms. So if anything it would be more accurate to
say that I have a thing for 150 Ohms.

The phrase "600 Ohms" didn't cross my lips until the phantom posted a
link to a web page that discussed the variation of impedance vs.
frequency that I had originally brought up. As a point of interest I
pointed out that the web page opened with a statement to the effect that
600 Ohm's was a good approximation to the characteristic impedance of
"UTP" at 1 kHz. The phantom next posted a table of calculated impedance
values vs. frequency which illustrated the variation of the
characteristic impedance vs. frequency. I then pointed out that the
table perfectly illustrated what I had originally said about the
variation of the characteristic impedance vs. frequency of these cables,
and based on the table I observed that 600 Ohms did seem to represent a
good approximation to the characteristic impedance across the voice
band. This was simply an observation and did not mean that I was
abandoning my claim that the characteristic impedance varied greatly
across the band, it simply meant that that if you were looking for an
average impedance value 600 Ohms is not a bad choice. I believe that at
that point I also reiterated again that for Hi-Fi audio applications the
line should be terminated in 150 Ohms. I will go out on a limb here and
state that 600 Ohms would probably be a better choice for terminations
in telephony applications because it would produce lower attenuation in
the voice band.

I don't have the slightest clue how to distinguish
a telegraph line from a telephone line

Speaks volumes about your ignorance.

The fact that you are unable to explain the difference after stating
that the construction of open wire telephone lines was patterned after
telegraph lines seems to say more about your ignorance than mine. If
you actually had any more of a clue than I do, you would simply explain
how to distinguish between the two types of line, the fact that you
haven't speaks volumes.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

[Eeyore]

John Byrns wrote:

If you go back to the beginning of the thread, you will
see that the first points I made were that the impedance of "standard
telephone line", a.k.a. 19 gauge toll cable, varies with frequency
across the audio band.

WTF is a 'toll cable'.

You're making yourself impossible to understand by talking Americanese.

Graham

[John Byrns]

In article ,
Eeyore wrote:

John Byrns wrote:

If you go back to the beginning of the thread, you will
see that the first points I made were that the impedance of "standard
telephone line", a.k.a. 19 gauge toll cable, varies with frequency
across the audio band.

WTF is a 'toll cable'.

You're making yourself impossible to understand by talking Americanese.

While the word Toll may not be used in connection with telephony in
Anglospeak, I would be surprised if you couldn't find the meaning of the
word in any good British dictionary. In any case understanding the
meaning of the word toll is not necessary for a technical understanding
of the operation of telephone cables. Simply delete the word toll from
the phrase 19 gauge toll cable so that it reads 19 gauge cable and you
should be able to easily understand. When I looked in my Telephony book
for the closest match to the characteristics of Iain's standard
telephone line, I found it was a cable described as 19 gauge toll cable,
unfortunately I didn't know the Anglospeak word for toll, so I was
unable to edit the phrase so you would be able to understand it, but for
the purposes of this discussion no meaning is lost if you simply ignore
the word.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

[Eeyore]

John Byrns wrote:

Eeyore wrote:
John Byrns wrote:

If you go back to the beginning of the thread, you will
see that the first points I made were that the impedance of "standard
telephone line", a.k.a. 19 gauge toll cable, varies with frequency
across the audio band.

WTF is a 'toll cable'.

You're making yourself impossible to understand by talking Americanese.

While the word Toll may not be used in connection with telephony in
Anglospeak, I would be surprised if you couldn't find the meaning of the
word in any good British dictionary.

A toll simply means a charge or fee. As in toll road, toll bridge etc. I failt
to see how that helps and I HAVE Googled for "toll cable" and found bugger all.

Are you totally incapable of explaining what you mean ?

Graham

[Eeyore]

John Byrns wrote:

When I looked in my Telephony book for the closest match to the
characteristics of Iain's standard
telephone line, I found it was a cable described as 19 gauge toll cable

So what's the damn conductor spacing ?

Graham

[John Byrns]

In article ,
Eeyore wrote:

John Byrns wrote:

Eeyore wrote:
John Byrns wrote:

If you go back to the beginning of the thread, you will
see that the first points I made were that the impedance of "standard
telephone line", a.k.a. 19 gauge toll cable, varies with frequency
across the audio band.

WTF is a 'toll cable'.

You're making yourself impossible to understand by talking Americanese.

While the word Toll may not be used in connection with telephony in
Anglospeak, I would be surprised if you couldn't find the meaning of the
word in any good British dictionary.

A toll simply means a charge or fee. As in toll road, toll bridge etc. I
failt
to see how that helps and I HAVE Googled for "toll cable" and found bugger
all.

They say "a picture is worth a thousand words", I tried Googling "toll
cable" and found a nice picture of both twisted pair and coaxial cables
on the 3rd hit:
http://scienceservice.si.edu/pages/005026.htm

The 4th hit was a discussion of "Fault Location on 19 AWG nonloaded
quadded toll telephone cable." I think the purpose of quading twisted
pair cable is to facilitate implementing phantom circuits

Are you totally incapable of explaining what you mean ?

As I explained in the paragraph you edited out, it is not necessary to
understand the meaning of the word "toll" to understand the technology
of telephone cables, simply forget you ever saw the word "toll", just
pretend it wasn't even there in the first place and you should be fine.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

[John Byrns]

In article ,
Eeyore wrote:

John Byrns wrote:

When I looked in my Telephony book for the closest match to the
characteristics of Iain's standard
telephone line, I found it was a cable described as 19 gauge toll cable

So what's the damn conductor spacing ?

I don't know the conductor spacing, but to be of any use you would also
probably need to know the type of insulating material used and its
thickness, as well as a few other construction details.

More useful for our purposes are the distributed constants per
loop-mile, which are as follows.

R = 86.0 Ohms
L = 0.001 Henry
C = 0.062 uFarad
G = 1.4 umhos


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

[Eeyore]

flipper wrote:

Eeyore wrote:
John Byrns wrote:

If you go back to the beginning of the thread, you will
see that the first points I made were that the impedance of "standard
telephone line", a.k.a. 19 gauge toll cable, varies with frequency
across the audio band.

WTF is a 'toll cable'.

Toll Cable -- Cable in which there are low capacitance quads or pairs
for long distance voice frequency transmission.

More searching suggests it simply means a 'long distance' cable. No mention of
quads whatever. Please provide evidence of the use of quads in telephony.

http://www.insulators.com/articles/openwire/

Graham

[Eeyore]

John Byrns wrote:

Eeyore wrote:
John Byrns wrote:

When I looked in my Telephony book for the closest match to the
characteristics of Iain's standard
telephone line, I found it was a cable described as 19 gauge toll cable

So what's the damn conductor spacing ?

I don't know the conductor spacing, but to be of any use you would also
probably need to know the type of insulating material used and its
thickness, as well as a few other construction details.

More useful for our purposes are the distributed constants per
loop-mile, which are as follows.

R = 86.0 Ohms
L = 0.001 Henry
C = 0.062 uFarad
G = 1.4 umhos

Per loop-mile of *WHAT* ?

Graham

[Eeyore]

John Byrns wrote:

Eeyore wrote:

A toll simply means a charge or fee. As in toll road, toll bridge etc. I
fail to see how that helps and I HAVE Googled for "toll cable" and found
bugger
all.

They say "a picture is worth a thousand words", I tried Googling "toll
cable" and found a nice picture of both twisted pair and coaxial cables
on the 3rd hit:
http://scienceservice.si.edu/pages/005026.htm

So you want to discuss coax now do you ? Why didn't you say so ? I though you
were talking about widely spaced parallel conductors or twisted pairs.

Maybe you simply don't know what you're talking about ? It certainly sounds like
it.

Graham

[Eeyore]

flipper wrote:

Eeyore wrote:

http://www.insulators.com/articles/openwire/

And why, for a discussion on toll cables, are you pasting a link that
specifically says "The principal types of toll or long distance wire
facilities are considered separately in the following Articles" that
you don't provide?

It's the only article that provided any info of value I found about so-called
'toll cables'.

Graham

[John Byrns]

In article ,
Eeyore wrote:

flipper wrote:

Eeyore wrote:

http://www.insulators.com/articles/openwire/

And why, for a discussion on toll cables, are you pasting a link that
specifically says "The principal types of toll or long distance wire
facilities are considered separately in the following Articles" that
you don't provide?

It's the only article that provided any info of value I found about so-called
'toll cables'.

Go to this web site:
http://www.pmillett.com/tecnical_books_online.htm
and download the book "Principles of Electricity Applied to Telephone
and Telegraph Work, A T &T, 1953, 354 pages".

This may be the book that is quoted on the "insulators.com" web site, at
any rate it includes extensive information on "toll cables" as well as
many other telephony related subjects. Page 167 does discuss the
"standard cable mile" and indicates that it has been dropped as a unit
of measurement. Page 181 mentions wire "quads" in passing, although it
does not mention what they were used for. I don't know for sure, but I
suspect the wire "quads" were used to maintain balance and reduce noise
on "phantom" circuits. Phantom circuits are extensively discussed in
the book, although mostly with respect to open wire lines.


Regards,

John Byrns

--
Surf my web pages at, http://fmamradios.com/

[Eeyore]

flipper wrote:

Eeyore wrote:
flipper wrote:
Eeyore wrote:

http://www.insulators.com/articles/openwire/

And why, for a discussion on toll cables, are you pasting a link that
specifically says "The principal types of toll or long distance wire
facilities are considered separately in the following Articles" that
you don't provide?

It's the only article that provided any info of value I found about so-called
'toll cables'.

Your difficulty in finding something appropriate doesn't make just
whatever you find appropriate and it won't be easy to find what you
seem to be looking for because direct voice on wire toll lines haven't
been in general use for half a century, or more.

'Toll' lines are long distance and called 'toll' because it's been
traditional to levy a per call/time used 'toll'.

It's traditional to levy a charge for local calls here as well, so the name makes
no sense to me.

Graham

[Eeyore]

flipper wrote:

To wit, the question was answered the first time someone explained it
meant 'long distance'

I think that only appeared in the last 24 hours.

Quite how you expect me to know about a curious Americanism is beyond me.

Graham

[Eeyore]

flipper wrote:

Eeyore wrote:

It's traditional to levy a charge for local calls here as well,

Bummer. I'm glad I don't have a phone line over there.

OTOH, our national long distance calls cost no more than a local one these days ! And
many telecom providers have a cheap package that bundles 'free' calls at certain
times of the day/week or even 24/7.

I can call the USA (an international call) and most of the 'developed world'
international destinations for no more than a couple of pence a minute. Beat that !

Graham