Author: DTCDate: 08:52 01-07-07
|
|
Jeff Liebermann wrote:
> Argh, that brings back fond nightmares of Ma Bell.
And of splicing damaged buried plant in a wet trench...that stuff had a
bite to it.
|
|
|
|
Author: Don BoweyDate: 10:07 01-07-07
|
|
On 6/30/07 10:44 PM, in article
8bHhi.2620$Od7.1551@newsread1.news.pas.earthlink.net, "DTC"
<no_spam@move_along_folks.foob> wrote:
> Mike Kaliski wrote:
>> ELF communications are carried out at very slow data rates, only a few
>> characters per hour at best.
>
> Actually its on the order of several characters per minute using a 64
> character "alphabet".
>
>> It is possible to communicate at a base band frequency of 0Hz. This is what
>> happens when you talk down a hard wired telephone or intercom. At a
>> telephone exchange (switching centre), the signals from each line are
>> modulated onto a higher frequency for onward transmission down a trunk wire
>> cable or fibre optic cable. The multiplexed high frequency modulated signals
>> are down converted back to audio frequencies once they reach the intended
>> destination.
>
> In the old T carrier (before 24 channel digital T1) carrier, each telephone
> conversation was modulated onto a low frequency radio frequency AM signal
> ranging from (and don't quote me as its been over thirty years since I
> worked T spans) 50 KC to 200 KC. Very similar in principle to the 5 kc wide
> AM radio station signals on the 530 kHz to 1700 kHz AM broadcast band.
The O Carrier systems went from a low of about 32 kHz up to 164 kHz if I
remember right. And the mainstay of long-haul communications (L Carrier)
channel bank, was 64 - 108 kHz.
One of the most strange Carrier Systems I worked with was a 1930s vintage H
Carrier, one channel ssb "system" operating at about 12 kHz, and it ran
without automatic synchronization. That was in the 60s. We used it as a
maintenance channel in a voice over data configuration for a gap-filler
radar site. I've never seen a more extreme merging of old and new
technologies.
Don
|
|
|
|
Author: Don BoweyDate: 10:14 01-07-07
|
|
On 6/30/07 11:25 PM, in article f67hdv$j96$1@nnrp.linuxfan.it, "John Smith
I" <assemblywizard@gmail.com> wrote:
> Radium wrote:
> ...
>
> You miss the simple point, the dc is the carrier ... instead of dc, you
> could put a 1 hz signal on the line and modulate it with your voice,
> indeed, you can put a 30 hz signal on the line and modulate it with your
> voice--if you can tollerate a bad 30 hz hum! But, who knows, perhaps
> you are tone deaf to the 30 hz hum and would like it ...
>
> JS
But you miss the basic point......
The topic was Amplitude Modulation.
|
|
|
|
Author: Don BoweyDate: 10:15 01-07-07
|
|
On 6/30/07 11:27 PM, in article f67hi1$j96$2@nnrp.linuxfan.it, "John Smith
I" <assemblywizard@gmail.com> wrote:
> Don Bowey wrote:
>
>> ...
>
> You are an idiot ... bother some one who has the time to take you to
> task ...
>
Open your mind.
|
|
|
|
|
|
On Jun 30, 2:55 pm, John Smith I <assemblywiz...@gmail.com> wrote:
> Radium wrote:
>
> > ...
>
> > I am getting conflicting answers. Some say it's possible to modulate a
> > carrier frequency at a frequency higher than the carrier frequency,
> > others say it isn't.
>
> > Who is right?
>
> Radium:
>
> Use simple logic, you can modulate a dc (0 Hz) with higher freq (voice),
> (hint, your telephone line is an example) right?
>
> However, when you get into RF--possible, usable, desirable are seperate
> and distinct things.
>
> Again, with simple logic, modulating a 30 CPS signal with limited voice
> freq (say 5K wide) is going to create a LOT of harmonics and mixed
> signals, ain't it? Suggesting a very wide band receiver would be needed
> to begin with ... in my humble opinion, and for various reasons, NO, it
> is NOT possible ...
>
> Regards,
> JS
radium, I applaud you in your interest generating discussion.
if there are no questions there are no answers; dumb or smart!
to me your questions came across wonderfully, and generated both
responses.
as humans we stand on two legs, most of us that is.
men get the honor and privilage to stand on three legs from time to
time.
this is our blessing and our curse!
ps. how would u like to change the cell phone industry? and your
discussion group of course!
remeber all things are possible!!!!!!!!!!!!!!!!
|
|
|
|
Author: John Smith IDate: 11:05 01-07-07
|
|
Don Bowey wrote:
> Open your mind.
>
Geesh!
Hook up a 20X linear behind an xmitter and see if you can't find some
artifacts ...
JS
|
|
|
|
Author: kevDate: 11:26 01-07-07
|
|
DTC wrote:
> Jeff Liebermann wrote:
>> Argh, that brings back fond nightmares of Ma Bell.
>
> And of splicing damaged buried plant in a wet trench...that stuff had a
> bite to it.
The Coax we used for the repeaters was fed with 250-0-250V DC and the
current was regulated at 49mA. The only time the cable jointers worked
on it the power feed was disabled.
|
|
|
|
Author: Don BoweyDate: 11:31 01-07-07
|
|
On 7/1/07 8:05 AM, in article f68ftd$afr$1@nnrp.linuxfan.it, "John Smith I"
<assemblywizard@gmail.com> wrote:
> Don Bowey wrote:
>
>> Open your mind.
>>
>
> Geesh!
>
> Hook up a 20X linear behind an xmitter and see if you can't find some
> artifacts ...
>
> JS
Sheesh....
That has nothing to do with helping someone understand AM. It appears you
are more interested in dumping your blog on this board, than providing
something to clarify the real answers for an electronic novice.
|
|
|
|
Author: Don BoweyDate: 11:32 01-07-07
|
|
On 7/1/07 8:05 AM, in article f68ftd$afr$1@nnrp.linuxfan.it, "John Smith I"
<assemblywizard@gmail.com> wrote:
> Don Bowey wrote:
>
>> Open your mind.
>>
>
> Geesh!
>
> Hook up a 20X linear behind an xmitter and see if you can't find some
> artifacts ...
>
> JS
By the way, I have. A 10B to a GPT750.
|
|
|
|
Author: John Smith IDate: 11:39 01-07-07
|
|
Don Bowey wrote:
> That has nothing to do with helping someone understand AM. It appears you
> are more interested in dumping your blog on this board, than providing
> something to clarify the real answers for an electronic novice.
So, you will decide what he needs to know and what he doesn't?
If he becomes aware of the more esoteric and trivial it is dangerous.
Get real control freak!
JS
|
|
|
|
Author: Don BoweyDate: 11:49 01-07-07
|
|
On 7/1/07 8:39 AM, in article f68hss$g38$1@nnrp.linuxfan.it, "John Smith I"
<assemblywizard@gmail.com> wrote:
> Don Bowey wrote:
>
>> That has nothing to do with helping someone understand AM. It appears you
>> are more interested in dumping your blog on this board, than providing
>> something to clarify the real answers for an electronic novice.
>
> So, you will decide what he needs to know and what he doesn't?
>
> If he becomes aware of the more esoteric and trivial it is dangerous.
>
> Get real control freak!
>
> JS
>
You really are thick headed if you can read Radium's posts and can't see how
he can't even deal with the real topic, much less the junk you toss in. The
more esoteric material should come after there is a grasp of the basics.
|
|
|
|
Author: John Smith IDate: 11:55 01-07-07
|
|
Don Bowey wrote:
> You really are thick headed if you can read Radium's posts and can't see how
> he can't even deal with the real topic, much less the junk you toss in. The
> more esoteric material should come after there is a grasp of the basics.
>
What, you have already given up on him and consigned him to a special
education class? Damn, I missed him being that dense, of course I tend
to give everyone the benefit of the doubt--even you ...
JS
|
|
|
|
Author: Jeff LiebermannDate: 12:11 01-07-07
|
|
John Smith I <assemblywizard@gmail.com> hath wroth:
>RHF wrote:
> > ...
>> Because "Radium" Touched Them With A Thirst
>> For Knowledge And A Quest For Answers.
>> ...
>I don't know, according to any instructor I have ever had respect for:
>"There are NO stupid questions, only stupid people who are afraid to ask
>questions."
I beg to differ. My favorite mentor/instructor/employer had a
different philosophy regarding questions and answers. His line was
something like "If you don't understand the problem, no solution is
possible". His method was to concentrate on understanding the
problem, refining the corresponding questions, and only then
concentrating on finding the answer. I would spend much more time
thinking about "what problem am I trying to solve" instead of
blundering prematurely toward some potentially irrelevant solution.
My problem with the original question is that it fails to associate
itself with anything recognizable as a real problem to solve or a
theory to expound. In my never humble opinion, if there was a
question under all that rubbish, it was quite well hidden and severely
muddled. He also introduced a substantial number of "facts" that
varied from irrelevant to incoherent to just plain wrong. The problem
for us in not in finding the answer, but in decoding the question.
There may not be any stupid questions, but there seem to be a
substantial number of marginal people asking questions. I answer some
techy questions in alt.internet.wireless. What I see, all too often,
are people that seem to think that no effort on their part is
necessary to obtain an answer. They exert no effort to read the FAQ,
no effort to supply what problem they are trying to solve, and no
effort to supply what they have to work with. In this case, Mr Radium
has either exerted no effort to compose his question in a form that
can be answered, or if there was such an effort, it has failed
miserably. He couldn't even find a suitable collection of newsgroups
for his question.
There may not be any stupid questions, but there certainly are
questions not worth the time attempting to answer. If Mr Radium had
left the question at the subject line:
"AM electromagnetic waves: 20 KHz modulation frequency on
an astronomically-low carrier frequency"
the question would have been easy to answer, as several people have
done. However, those that answered and I all did the same thing. We
extracted from the word salad question what we thought was something
resembling a coherent question, and ignored the rest of the rubbish.
In other words, we did the necessary simplification and problem
reduction, and discarded the bulk of the incoherent residue. There
may not be any stupid questions, but if you bury it under a sufficient
number of words, it may closely resemble a stupid question.
>Depends ... I guess.
>JS
Well, let's see:
<http://groups.google.com/groups?as_q=%22guess%28tm%29%22&as_uauthors=Jeff+Lieber
mann>
533 guesses, out of about 16,000 postings, which I guess(tm) isn't all
that bad.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
|
|
|
|
Author: Don BoweyDate: 12:12 01-07-07
|
|
On 7/1/07 8:55 AM, in article f68ipr$hne$1@nnrp.linuxfan.it, "John Smith I"
<assemblywizard@gmail.com> wrote:
> Don Bowey wrote:
>
>> You really are thick headed if you can read Radium's posts and can't see how
>> he can't even deal with the real topic, much less the junk you toss in. The
>> more esoteric material should come after there is a grasp of the basics.
>>
>
> What, you have already given up on him and consigned him to a special
> education class? Damn, I missed him being that dense, of course I tend
> to give everyone the benefit of the doubt--even you ...
>
> JS
As a matter of fact, as you should be able to see, I am working here in
support of his learning process while you do nothing but rag on in support
of your blog.
|
|
|
|
Author: John Smith IDate: 14:11 01-07-07
|
|
Don Bowey wrote:
> As a matter of fact, as you should be able to see, I am working here in
> support of his learning process while you do nothing but rag on in support
> of your blog.
>
>
idiot
JS
|
|
|
|
Author: Don BoweyDate: 14:18 01-07-07
|
|
On 7/1/07 11:11 AM, in article f68qps$8gt$1@nnrp.linuxfan.it, "John Smith I"
<assemblywizard@gmail.com> wrote:
> Don Bowey wrote:
>
>> As a matter of fact, as you should be able to see, I am working here in
>> support of his learning process while you do nothing but rag on in support
>> of your blog.
>>
>>
>
> idiot
>
> JS
OK, you win.
|
|
|
|
Author: John Smith IDate: 14:19 01-07-07
|
|
Don Bowey wrote:
> [pure crap!]
"In the mid-1870s, a form of amplitude modulation—initially called
"undulatory currents"—was the first method to successfully produce
quality audio over telephone lines. Beginning with Reginald Fessenden's
audio demonstrations in the early 1900s, it was also the original method
used for audio radio transmissions, and remains in use by some forms of
radio communication—"AM" is often used to refer to the mediumwave
broadcast band (see AM radio)."
Taken from this URL: http://en.wikipedia.org/wiki/Amplitude_modulation
And, please read the WHOLE PAGE before making a larger idiot of yourself ...
JS
|
|
|
|
Author: Don BoweyDate: 14:46 01-07-07
|
|
On 7/1/07 11:19 AM, in article f68r8s$asb$1@nnrp.linuxfan.it, "John Smith I"
<assemblywizard@gmail.com> wrote:
> Don Bowey wrote:
>> [pure crap!]
>
> "In the mid-1870s, a form of amplitude modulation‹initially called
> "undulatory currents"‹was the first method to successfully produce
> quality audio over telephone lines. Beginning with Reginald Fessenden's
> audio demonstrations in the early 1900s, it was also the original method
> used for audio radio transmissions, and remains in use by some forms of
> radio communication‹"AM" is often used to refer to the mediumwave
> broadcast band (see AM radio)."
>
> Taken from this URL: http://en.wikipedia.org/wiki/Amplitude_modulation
>
> And, please read the WHOLE PAGE before making a larger idiot of yourself ...
>
> JS
I didn't read the link, as it has nothing to do with this string.
You posted to Radium's question about Amplitude Modulation, saying that on a
telephone line, the DC voltage is the Carrier and the microphone current (or
voltage if you prefer) is the modulation. Now THAT is un-pure crap and it
is what I responded to and which you deleted in this post hoping to look
better, which you don't.
I already conceded to your ignorance, so you really didn't need to post
more, but thanks for the opportunity to help.
|
|
|
|
Author: John Smith IDate: 14:53 01-07-07
|
|
Don Bowey wrote:
> [more crap!]
Oh, that explains it, your understanding of amplitude modulation is:
AM = Black Magic.
ROFLOL!
JS
|
|
|
|
Author: RadiumDate: 15:16 01-07-07
|
|
On Jul 1, 7:24 am, shawn.cormi...@gmail.com wrote:
> radium, I applaud you in your interest generating discussion.
>
> if there are no questions there are no answers; dumb or smart!
>
> to me your questions came across wonderfully, and generated both
> responses.
>
> as humans we stand on two legs, most of us that is.
>
> men get the honor and privilage to stand on three legs from time to
> time.
>
> this is our blessing and our curse!
>
Thanks for your understanding.
> ps. how would u like to change the cell phone industry?
Analog cells phones should stop using FM and should start using AM
between frequencies of 40,000 to 285,000 Hz.
As I learned recently, 40 KHz is the minimum radio frequency required
to coherently transmit/receive audio signals. The highest sound a
human can hear is 20 KHz. The radio-frequency used must be at least 2x
the intended frequency of the information being transmitted/received.
I chose 285 KHz to be the highest radio frequency for cell-phones
because it is roughly the highest-frequency categorized as "long wave"
radio.
> and your
> discussion group of course!
You mean the anti-yahoo group?
http://groups.google.com/group/yahoo_stinks?lnk=li&hl=en
|
|
|
|
|
