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Forummaster
| | Posted on Sunday, March 16, 2003 - 10:38 pm: | 
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I ran across an interesting article about interference that might change everything you ever thought true about the subject.
Here are some excerpts.
"Interference is a metaphor that paints an old limitation of technology as a fact of nature." So says David P. Reed, electrical engineer, computer scientist, and one of the architects of the Internet. If he's right, then spectrum isn't a resource to be divvied up like gold or parceled out like land. It's not even a set of pipes with their capacity limited by how wide they are or an aerial highway with white lines to maintain order.
Spectrum is more like the colors of the rainbow, including the ones our eyes can't discern. Says Reed: "There's no scarcity of spectrum any more than there's a scarcity of the color green. We could instantly hook up to the Internet everyone who can pick up a radio signal, and they could pump through as many bits as they could ever want. We'd go from an economy of digital scarcity to an economy of digital abundance."
And here is the kicker ---
"Photons, whether they are light photons, radio photons, or gamma-ray photons, simply do not interfere with one another," he explains. "They pass through one another."
"If photons can pass through one another, then they aren't actually occupying space at all, since the definition of 'occupying' is 'displacing.'
But if photons don't interfere, why do our radios and cellphones go all crackly? Why do we sometimes pick up two stations at once and not hear either well enough?
The problem isn't with the radio waves. It's with the receivers: "Interference cannot be defined as a meaningful concept until a receiver tries to separate the signal. It's the processing that gets confused, and the confusion is highly specific to the particular detector," Reed says. Interference isn't a fact of nature. It's an artifact of particular technologies. This should be obvious to anyone who has upgraded a radio receiver and discovered that the interference has gone away: The signal hasn't changed, so it has to be the processing of the signal that's improved. The interference was in the eye of the beholder all along. Or, as Reed says, "Interference is what we call the information that a particular receiver is unable to separate."
You can find the full article here.
Full Article |
de
| | Posted on Sunday, March 16, 2003 - 10:52 pm: |
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Perspective is the key. What is a weed? A weed is anything that is growing where we do not like it growing.
Along the same lines, if something prevents one from receiving their desired communication or hinders a desired communication or just annoys us when we attempt a desired communication it is something there that we do not wish to be there. Hence it is interference.
So interference could be something as uncontrolable as lightning derived static to direct, deliberate and blantant interference.
Interference is just merely noise which annoys us. |
Tech833
| | Posted on Monday, March 17, 2003 - 10:42 am: |
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Interference is an unpredicted or unwanted result given to us from our equipment when creating or deciphering RF.
Didn't I just have this conversation with you on the phone?? There is no interference that cannot be solved. |
DeadlyEyes
| | Posted on Monday, March 17, 2003 - 6:12 pm: |
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Re 833
No I do not believe that I have ever had the pleasure of chatting with you on the twisted pair.
The only interference I have had that ticked me off to no end was interference that I could not ever hope to stop--Summer Lightening Crashes on 80 and 160 Meters. Real ear bangers at times.
Signed
DE |
Forummaster
| | Posted on Monday, March 17, 2003 - 7:58 pm: |
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DeadlyEyes,
Tech833 is referring to me. We talk occasionally and he gives me lessons on antennas. He's a good teacher I'm just a slow learner. |
de
| | Posted on Monday, March 17, 2003 - 10:58 pm: |
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RE Fm...
Remember there is no such thing as a slow learner when it comes to practical radio knoledge. We all learn what we need to know when the time comes.
AND many times the CB clan knows more about antennas then the Ham group. I do not know how many dang times I have read posts on how to make a simple dipole. It would seem that the making of a simple meger dipole or a simple meger 3 element beam or a simple 2 element quad would be required nay demanded knoledge taught in our ham classes for new prospective hams. But sadly it is not. All the teachers of today seem interested in is teaching "Just" the questions and answers. They leave off the important stuff--how to put together an antnna, how to build simple antnnas yourself from common household objects, how to hide the antenna if needed, what ascessories are required, how to cure simple RFI and general radio operating procedures.
Hmmmm in many respects the long time CBer knows more general knoledge about antennas and their general working functionsn than the no code ham techie.
Salute if you do
DE |
Bigbob
| | Posted on Tuesday, March 18, 2003 - 6:48 am: |
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Is a myth the feminine of mythter?lol |
Tech833
| | Posted on Tuesday, March 18, 2003 - 9:56 am: |
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DE,
The CBer only need to concern him/her self with one band. The ham needs to concern his/her geeky self with many bands from below 1 MHz. to the lightwaves. Antenna are much different. One design does not cover all.
However, you are correct that the simple antenna types should be common knowledge to pass a ham exam. Not long ago, one would have to understand grid leak to pass the exams. That is no longer the case as nobody seems capable of building their own gear anymore. Hams are quick to call equipment 'junk' without the capability of designing and building gear that is better.
Of course, the part 90 CB rules prohibit building one's own gear, as all CB gear (both transmitters and receivers) needs to be type accepted. Therefore, the only experimentation left for the CBer is antennas. That may be an advantage here. |
Simon
| | Posted on Tuesday, March 18, 2003 - 11:47 am: |
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DE
Hear Hear. Spent 4 years trying to get our local ham club to stop teaching questions and answers parrot fashion.Now Ive gone onestage further - approached the local community college to add a ham/electronics class thatI would teach (spent 6 yearsdrumming radio tradesin apprentices for Royal Australian Air Force). |
Mr_Rf
| | Posted on Tuesday, March 18, 2003 - 10:22 pm: |
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That article dated April 1st by chance? lol |
bruce
| | Posted on Tuesday, March 18, 2003 - 10:36 pm: |
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reminds me of the thick into thin coax passive linear |
bullet
| | Posted on Friday, March 21, 2003 - 9:00 pm: |
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Weakeststation
| | Posted on Saturday, March 22, 2003 - 10:54 am: |
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The problems is with the receivers ey??? :LOL: Brand new radios and i can hear the interfence from cell phones computers, engine noise and other..LOL... I don't agree with the article that its' the receiver.. LOL.. sorry but my opinion... let alone skip.... |
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