Hum from phone wires running next to mains?

On Thu, 06 Mar 2008 16:04:57 +0000, Ivor Jones wrote:

"ehsjr" wrote in message
news:3HTzj.19815$ES.6877@trnddc05

[snip]

: : Non-standard usage can make your posts harder to : : understand, and
more difficult for others. Apparently, : : you don't care. I'm just
adding one more response to : : let you know that your non-standard
usage is not : : appreciated.

Ok, you're the *second* complaint in 10+ years. When that figure gets to
a noticable percentage, I might sit up and take notice.

Ivor

: :
: : Ed


Third. But don't worry about me, because *plonk*

In article , says...
krw wrote:
In article , says...
krw wrote:
In article ,
says...
Foxtrot wrote:

... snip ...

Is there is a greaterlikelihood of hum if I connect a "2 wire"
phone extension by using one wire from a twisted pair and taking
the second wire from a different twisted pair?

Yes. The idea of twisted pairs is that an interference appears on
both lines, and thus tends to cancel itself. Separating the lines
makes it easy for unequal induction.

Twisting also makes the loop area low (average over a long stretch
is nil). Separating them makes a large loop, increasing the size of
the antenna.

That is not a valid analysis. It is a transmission
line, not an antenna.

It sure as hell is. Open up the loop and it makes a *wonderful*
antenna.

It's a "wonderful" antenna regardless. But it's a
single conductor long wire antenna. Changing the
spacing is merely changing the effective diameter of the
single conductor. To get any other effect requires
spacing that is significant in terms of wavelength
(greater than perhaps 1/8th of a wavelength, for
example).

Absolute nonsense.

Consider that the effect, both for relatively small
gauge cables, such as the ubiquitous 26 gauge used
today, is *exactly* the same as the effect on the open
wire lines used in the 30's and 40's with several inches
of separate between a pair of much larger copperclad
steel wires. And while the twist on some cable is
measured per inch, on typical telephone cable it is
measured in many inches per twist, and on those old open
wire lines it was in hundreds of yards per twist.

...and open-wire transmission lines won't pick up stray noise?

It picks up as much, or as little, as unshielded twisted
pair of smaller gauge and closer spacing. That's the
point... there isn't any difference. In either case
what you have is a single conductor longwire antenna, not
a loop antenna, until the spacing is a significant fraction
of a wavelength.

Bullsnit. Try reading your EE100 text again.


--
Keith

krw wrote:
In article , says...
krw wrote:
In article , says...
krw wrote:
In article ,
says...
Foxtrot wrote:

... snip ...

Is there is a greaterlikelihood of hum if I connect a "2 wire"
phone extension by using one wire from a twisted pair and taking
the second wire from a different twisted pair?

Yes. The idea of twisted pairs is that an interference appears on
both lines, and thus tends to cancel itself. Separating the lines
makes it easy for unequal induction.

Twisting also makes the loop area low (average over a long stretch
is nil). Separating them makes a large loop, increasing the size of
the antenna.

That is not a valid analysis. It is a transmission
line, not an antenna.

It sure as hell is. Open up the loop and it makes a *wonderful*
antenna.

It's a "wonderful" antenna regardless. But it's a
single conductor long wire antenna. Changing the
spacing is merely changing the effective diameter of the
single conductor. To get any other effect requires
spacing that is significant in terms of wavelength
(greater than perhaps 1/8th of a wavelength, for
example).

Absolute nonsense.

Actually, that's why it works so well as a balanced
transmission line.

Consider that the effect, both for relatively small
gauge cables, such as the ubiquitous 26 gauge used
today, is *exactly* the same as the effect on the open
wire lines used in the 30's and 40's with several inches
of separate between a pair of much larger copperclad
steel wires. And while the twist on some cable is
measured per inch, on typical telephone cable it is
measured in many inches per twist, and on those old open
wire lines it was in hundreds of yards per twist.

...and open-wire transmission lines won't pick up stray noise?

It picks up as much, or as little, as unshielded twisted
pair of smaller gauge and closer spacing. That's the
point... there isn't any difference. In either case
what you have is a single conductor longwire antenna, not
a loop antenna, until the spacing is a significant fraction
of a wavelength.

Bullsnit. Try reading your EE100 text again.

I'd suggest studying transmission lines and antennas.
Start with Kraus.

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

PCPaul wrote:
Ivor Jones wrote:
"ehsjr" wrote in message

[snip]

: : Non-standard usage can make your posts harder to : :
understand, and more difficult for others. Apparently, : : you
don't care. I'm just adding one more response to : : let you
know that your non-standard usage is not : : appreciated.

Ok, you're the *second* complaint in 10+ years. When that figure
gets to a noticable percentage, I might sit up and take notice.

Third. But don't worry about me, because *plonk*

The only problem with a straight plonk is that other peoples quotes
of the plonkee shine through. The advantage of that is that one
has a chance to decide the plonk should be retracted.

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: http://cbfalconer.home.att.net
Try the download section.



--
Posted via a free Usenet account from http://www.teranews.com

"CBFalconer" wrote in message

: : PCPaul wrote:
: : : Ivor Jones wrote:
: : : : "ehsjr" wrote in message
: : : :
: : : : [snip]
: : : :
: : : : : : Non-standard usage can make your posts harder
: : : : : : to : :
: : : : understand, and more difficult for others.
: : : : Apparently, : : you don't care. I'm just adding one
: : : : more response to : : let you know that your
: : : : non-standard usage is not : : appreciated.
: : : :
: : : : Ok, you're the *second* complaint in 10+ years.
: : : : When that figure gets to a noticable percentage, I
: : : : might sit up and take notice.
: : :
: : : Third. But don't worry about me, because *plonk*
: :
: : The only problem with a straight plonk is that other
: : peoples quotes of the plonkee shine through. The
: : advantage of that is that one has a chance to decide
: : the plonk should be retracted.

Indeed. But even three complaints in 10+ years (and I have my doubts on
the validity of at least one of them) is not worth worrying about. I post
a *lot* of articles on Usenet in 20+ groups, 3 complaints doesn't even
register. 3000 might, or even 300. But 3..? Try harder.

BTW nobody has yet mentioned which piece of flaky software gets upset by a
: instead of a


Ivor

In article , says...
krw wrote:
In article , says...
krw wrote:
In article , says...
krw wrote:
In article ,
says...
Foxtrot wrote:

... snip ...

Is there is a greaterlikelihood of hum if I connect a "2 wire"
phone extension by using one wire from a twisted pair and taking
the second wire from a different twisted pair?

Yes. The idea of twisted pairs is that an interference appears on
both lines, and thus tends to cancel itself. Separating the lines
makes it easy for unequal induction.

Twisting also makes the loop area low (average over a long stretch
is nil). Separating them makes a large loop, increasing the size of
the antenna.

That is not a valid analysis. It is a transmission
line, not an antenna.

It sure as hell is. Open up the loop and it makes a *wonderful*
antenna.

It's a "wonderful" antenna regardless. But it's a
single conductor long wire antenna. Changing the
spacing is merely changing the effective diameter of the
single conductor. To get any other effect requires
spacing that is significant in terms of wavelength
(greater than perhaps 1/8th of a wavelength, for
example).

Absolute nonsense.

Actually, that's why it works so well as a balanced
transmission line.

Sure, it's a transmission line for the t-wave on the line. It's
also an antenna, with the gain proportional to the area of the loop.
Try running that open line next to a power line.

Consider that the effect, both for relatively small
gauge cables, such as the ubiquitous 26 gauge used
today, is *exactly* the same as the effect on the open
wire lines used in the 30's and 40's with several inches
of separate between a pair of much larger copperclad
steel wires. And while the twist on some cable is
measured per inch, on typical telephone cable it is
measured in many inches per twist, and on those old open
wire lines it was in hundreds of yards per twist.

...and open-wire transmission lines won't pick up stray noise?

It picks up as much, or as little, as unshielded twisted
pair of smaller gauge and closer spacing. That's the
point... there isn't any difference. In either case
what you have is a single conductor longwire antenna, not
a loop antenna, until the spacing is a significant fraction
of a wavelength.

Bullsnit. Try reading your EE100 text again.

I'd suggest studying transmission lines and antennas.
Start with Kraus.

Get real Floyd!

--
Keith

In alt.engineering.electrical Ivor Jones wrote:
|
|
| "CBFalconer" wrote in message
|
| : : PCPaul wrote:
| : : : Ivor Jones wrote:
| : : : : "ehsjr" wrote in message
| : : : :
| : : : : [snip]
| : : : :
| : : : : : : Non-standard usage can make your posts harder
| : : : : : : to : :
| : : : : understand, and more difficult for others.
| : : : : Apparently, : : you don't care. I'm just adding one
| : : : : more response to : : let you know that your
| : : : : non-standard usage is not : : appreciated.
| : : : :
| : : : : Ok, you're the *second* complaint in 10+ years.
| : : : : When that figure gets to a noticable percentage, I
| : : : : might sit up and take notice.
| : : :
| : : : Third. But don't worry about me, because *plonk*
| : :
| : : The only problem with a straight plonk is that other
| : : peoples quotes of the plonkee shine through. The
| : : advantage of that is that one has a chance to decide
| : : the plonk should be retracted.
|
| Indeed. But even three complaints in 10+ years (and I have my doubts on
| the validity of at least one of them) is not worth worrying about. I post
| a *lot* of articles on Usenet in 20+ groups, 3 complaints doesn't even
| register. 3000 might, or even 300. But 3..? Try harder.
|
| BTW nobody has yet mentioned which piece of flaky software gets upset by a
| : instead of a

It looks like maybe PCPaul's software, which identifies itself as
"Pan/0.132 (Waxed in Black)" might be getting them confused. I don't
know if it because it is a ":" or because you are using double ": :".
I don't see a logical reason for the software to get confused. Once
it has parsed passed the headers and into the content body, the logic
should simply be to look for any special character that is repeated
at the beginning of every line. I believe a "." might have problems
because it gets used as an escape during transmission in NNTP. But
even that has generally worked for me (so most software still handles
it OK).

Apparently what his software did was dismiss line breaks of the message
he quoted, and mingle the ": :" into the message.

What can be confusing to people is the double ": :" usage. That makes
it look like you quoted with ":" what your previous poster quoted with
":". So instead of that quoted text being understood as the part of
the parent post, it gets misunderstood as part of the grandparent post.
It also looks like you or your software replaced other people's quoting
character with ":" or ": :". Whatever anyone uses, that should be
left as is (unless it is clearly broken).

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / |
|------------------------------------/-------------------------------------|

wrote:
Ivor Jones wrote:

.... snip ...

Indeed. But even three complaints in 10+ years (and I have my
doubts on the validity of at least one of them) is not worth
worrying about. I post a *lot* of articles on Usenet in 20+
groups, 3 complaints doesn't even register. 3000 might, or even
300. But 3..? Try harder.

BTW nobody has yet mentioned which piece of flaky software gets
upset by a : instead of a

It looks like maybe PCPaul's software, which identifies itself as
"Pan/0.132 (Waxed in Black)" might be getting them confused. ...

Piggy-backing, because Jones is plonked. Obviously he doesn't get
complaints, since all those who would complain have been ignored
and have plonked him. Most plonkers don't bother to advise the
plonkee.

--
[mail]: Chuck F (cbfalconer at maineline dot net)
[page]: http://cbfalconer.home.att.net
Try the download section.



--
Posted via a free Usenet account from http://www.teranews.com

On Fri, 7 Mar 2008 10:23:55 -0500, "daestrom"
wrote:


"Ivor Jones" wrote in message
...

"CBFalconer" wrote in message

: : Ivor Jones wrote:

[snip]

: : I replaced your non-standard (: quote markers with
: : the normal ''. Please don't use thos non-standard
: : characters. They foul up other software.

With respect, and without wishing to start a row, that's *your* problem. I
use non-standard quote marks for a purpose. If your system can't cope with
that, then it's up to *you* to do something about it. I have been using
the quote marks I use for several years and you are the first to complain.


Here's a third complaint. The only thing worse is those that post in html
and so some newsreaders won't automatically mark the quoted text at all.

daestrom

I don't know about "only thing worse", there are lots of
worse things but make it a 4th complaint because it should
not be someone else's burden to cope with non-standard quote
marks - even if many newsreader apps can do so.

wrote in message


[snip]

: What can be confusing to people is the double ": :"
: usage. That makes
: it look like you quoted with ":" what your previous
: poster quoted with ":". So instead of that quoted text
: being understood as the part of
: the parent post, it gets misunderstood as part of the
: grandparent post.
: It also looks like you or your software replaced other
: people's quoting character with ":" or ": :". Whatever
: anyone uses, that should be
: left as is (unless it is clearly broken).

It's OE Quotefix and I've found the setting that caused it to convert the
existing quote marks and I've disabled that, so they should now be as they
were.

Hope this helps.

Ivor