Hum from phone wires running next to mains?

In article ,
lid says...

"krw" wrote in message
t

[snip]

: *MY* system is configured properly. *YOU* have the
: problem. ...and more than one.

Eh..? *I* don't have a problem.

Yes, you do.

Seems to me it's *you* that has the
problem, if you can't cope with a simple : character in a plain text
message.

Again, it is not *I* who has a problem.

--
Keith

In article , says...
krw wrote:
In article , says...
JosephKK wrote:
On Thu, 06 Mar 2008 15:40:31 -0900, (Floyd L.
Davidson) wrote:

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.

I have built many twin lead antennas for VHF use. The distinction is
not so clear as you are advertising.

In fact, it is. What is an folded dipole? As opposed to a loop?

...and they work rather well as antennas, just as any open line.

There is a fundamental difference between a folded
dipole and a loop antenna. It is exactly as I
suggested above.

Folded dipoles don't work so well if you twist them, though.

You apparently have no idea what a folded dipole *is*,
in theory. Consider another similar construction, which
does not change anything in the same way that a loop
does: multiwire rhombics. The effects are the same as
experienced with a folded dipole (the two conductors equate
to one larger conductor).

The claim that separation between the two wires of a
twisted pair (or even an untwisted parallel pair)
transmission line has the effect of a loop antenna is
false.

The idea that this is covered in "EE100" is equally
ridiculous, and the dismissal (in a different message)
of my suggestion to read the work of Kraus, where it is
in fact discussed in detail, suggests that some people
really should read Kraus.

Keep up the baloney Floyd. You're good at it.

--
Keith

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

There is a fundamental difference between a folded
dipole and a loop antenna. It is exactly as I
suggested above.

Folded dipoles don't work so well if you twist them, though.

You apparently have no idea what a folded dipole *is*,
in theory. Consider another similar construction, which
does not change anything in the same way that a loop
does: multiwire rhombics. The effects are the same as
experienced with a folded dipole (the two conductors equate
to one larger conductor).

The claim that separation between the two wires of a
twisted pair (or even an untwisted parallel pair)
transmission line has the effect of a loop antenna is
false.

The idea that this is covered in "EE100" is equally
ridiculous, and the dismissal (in a different message)
of my suggestion to read the work of Kraus, where it is
in fact discussed in detail, suggests that some people
really should read Kraus.

Keep up the baloney Floyd. You're good at it.

If it were baloney you should be able to demonstrate it
fairly easily; instead you post insults and can't follow
up to even the lowest level of technical discussion.

Do you understand the comparison between the effects of
multiple wires used in rhombic design to the multiple
wires used for folded dipole design? (And do you
understand the one difference?)

And do you have any idea how silly it is to say that
folded dipoles don't work if they are twisted???? Of
course many, if not most, homemade folded dipoles used
at HF frequencies do in fact end up being twisted...

Go to a library, read Kraus.

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

krw wrote:
lid says...

.... snip misquoted stuff ...

Nobody's forcing you to read my message. Which is written in
plain text, by the way. If you can't cope with a simple :
character in a bit of ASCII text, tough.

This post typifies your attitude toward you reader. The question
is, why do *you* bother writing if you have no interest in your
reader?

Well, there have been detailed intelligent postings of reasons to
comply, and postings of general malignancy, and I have avoided at
least 1/2 of all that so far. I see no reason to retract my plonk
so far. I wonder how many other plonkers there are out there.

--
[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

In alt.engineering.electrical Ivor Jones wrote:
|
| "Stuart" wrote in message
|
| : In article ,
| : Ivor Jones wrote:
|
| : Nobody's forcing you to read my message. Which is
| : written in plain text, by the way. If you can't cope
| : with a simple : character in a bit of ASCII text,
| : tough.
| :
| : I think the only real issue is that ":" could appear
| : naturally in a "plain text" email as it is a standard
| : punctuation mark, "" is far less likely though I
| : suppose ": :" is unlikely too.
|
| But what is the objection..? I just don't get it. I've been on Usenet for
| over 10 years and nobody has *ever* complained about this before.

The fact that you are DOUBLE indenting makes it appear that you have
quoted ONLY the quoting of the previous poster. It doesn't matter if
the indenting is ": " or ": :" or even " ". It is misleading.

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

In alt.engineering.electrical Ivor Jones wrote:
|
|
| "Stuart" wrote in message
|
|
| [snip]
|
| : Can't say as it caused me any issues here except the
| : fact of ": :" putting it down to the second level of
| : quoting as if you had used " "
|
| Fixed. That *was* a misconfiguration ;-)

What was fixed? The same issue still exists. It is NOT an issue of what
the character is. It is an issue of DOUBLE indenting.

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

On 2008-03-09, Ivor Jones wrote:


"Stuart" wrote in message


[snip]

: Can't say as it caused me any issues here except the
: fact of ": :" putting it down to the second level of
: quoting as if you had used " "

Fixed. That *was* a misconfiguration ;-)

Not quite. You're now quoting with ": " compared to ": :" previously.

--
David Taylor

wrote in message

: In alt.engineering.electrical Ivor Jones
: wrote:

[snip]

: | But what is the objection..? I just don't get it.
: | I've been on Usenet for over 10 years and nobody has
: | *ever* complained about this before.
:
: The fact that you are DOUBLE indenting makes it appear
: that you have
: quoted ONLY the quoting of the previous poster. It
: doesn't matter if
: the indenting is ": " or ": :" or even " ". It is
: misleading.

I put a space in, not a double indent. I have now modifed the system so it
puts a single : instead of converting the previous quote mark to a : which
it did before. So now you should be getting : and not : :

Regarding it appearing that I am quoting only the previous poster, I
normally only do that anyway unless the thread dictates otherwise, but I
don't see how it's misleading because I ensure I quote the names of the
previous posters that I'm including, see the top of this message.

Ivor

"CBFalconer" wrote in message


[snip]

: Well, there have been detailed intelligent postings of
: reasons to comply, and postings of general malignancy,
: and I have avoided at least 1/2 of all that so far. I
: see no reason to retract my plonk so far. I wonder how
: many other plonkers there are out there.

Indeed.

Ivor

wrote in message

: In alt.engineering.electrical Ivor Jones
: wrote:
: |
: |
: | "Stuart" wrote in message
: |
: |
: | [snip]
: |
: | : Can't say as it caused me any issues here except
: | : the fact of ": :" putting it down to the second
: | : level of quoting as if you had used " "
: |
: | Fixed. That *was* a misconfiguration ;-)
:
: What was fixed? The same issue still exists. It is
: NOT an issue of what the character is. It is an issue
: of DOUBLE indenting.

No, that's a space, not another indent.

If it were double indenting it would be :: or : or whatever not : : or :



Ivor