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#41
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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* |
#43
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Hum from phone wires running next to mains?
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) |
#44
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Hum from phone wires running next to mains?
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 |
#45
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Hum from phone wires running next to mains?
"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 |
#46
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Hum from phone wires running next to mains?
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 |
#47
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Hum from phone wires running next to mains?
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 / | |------------------------------------/-------------------------------------| |
#48
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Hum from phone wires running next to mains?
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 |
#49
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Hum from phone wires running next to mains?
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. |
#50
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Hum from phone wires running next to mains?
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 |
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