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#1
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T wrote:
All i want is to be able to pick up the signal from my "transmitter" with an am-radio across the room. Ok. I have been watching the discussion on this thread for a while now. Some people have attempted to help, others just wasted band width. The situation is that you want to do a demonstration that involves transmitting a signal and receiving it. FCC part 15 regulations specify that a low power am transmitter can not exceed a very low power level ( I don't remember off hand how much) and the antenna must be attached to the transmitter and must not exceed about 5 or 6 feet. Any am transmitter that meets these limitations will function in the manner you desire to exhibit. Any am receiver will detect the signal from the transmitter over a distance of 50 to several hundred feet. There are many suppliers of these devices. Just do a Google search for "Part 15 Transmitters" and you will find more than you can use. Siple receivers can be obtained from similar sources. I do not know what you intend to do but don't concern your self to much on finding the electronic equipment you need, it is readly available and fairly inexpensive. Good Luck David Nagel WD9BDZ |
#2
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Thank you mr. kelly for trying to help me out, but obviously richard
is too hostile to want someone else, even a kid, to learn anything about radio engineering. [you know, since he probably never tinkered with electronics when he was a kid and asked someone for advice] = sarcasm i'm slightly disappointed in him. a grown man, who attacks eager to learn children over the internet. do you not have friends? a life? besides if you don't help people, but instead show them hostility, don't you think they may become discouraged? maybe even give it up and quit? if there is no one interested in this type of engineering, then it may cease to exist. all i'm saying is, be an encourager, help others, and go with god. "since new developments are the products of a creative mind, we must therefore stimulate and ENCOURAGE that type of mind in every way possible." -george washington carver sorry to be so short, and thanks to everyone who tried to help, taylor |
#3
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![]() "T" wrote in message oups.com... Thank you mr. kelly for trying to help me out, but obviously richard is too hostile to want someone else, even a kid, to learn anything about radio engineering. [you know, since he probably never tinkered with electronics when he was a kid and asked someone for advice] = sarcasm i'm slightly disappointed in him. a grown man, who attacks eager to learn children over the internet. do you not have friends? a life? besides if you don't help people, but instead show them hostility, don't you think they may become discouraged? maybe even give it up and quit? if there is no one interested in this type of engineering, then it may cease to exist. all i'm saying is, be an encourager, help others, and go with god. "since new developments are the products of a creative mind, we must therefore stimulate and ENCOURAGE that type of mind in every way possible." -george washington carver sorry to be so short, and thanks to everyone who tried to help, taylor Hi taylor Did you google loop stick antenna? Jerry |
#4
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![]() "T" wrote in message oups.com... Thank you mr. kelly for trying to help me out, but obviously richard is too hostile to want someone else, even a kid, to learn anything about radio engineering. [you know, since he probably never tinkered with electronics when he was a kid and asked someone for advice] = sarcasm i'm slightly disappointed in him. a grown man, who attacks eager to learn children over the internet. do you not have friends? a life? besides if you don't help people, but instead show them hostility, don't you think they may become discouraged? maybe even give it up and quit? if there is no one interested in this type of engineering, then it may cease to exist. all i'm saying is, be an encourager, help others, and go with god. "since new developments are the products of a creative mind, we must therefore stimulate and ENCOURAGE that type of mind in every way possible." -george washington carver sorry to be so short, and thanks to everyone who tried to help, taylor Oh no! Another victim! This time it is an alleged kid. I thought everybody gave him plenty of good, free advice. |
#5
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On Mon, 12 Feb 2007 18:59:24 -0500, "Stefan Wolfe"
wrote: "T" wrote in message roups.com... Thank you mr. kelly for trying to help me out, but obviously richard is too hostile to want someone else, even a kid, to learn anything about radio engineering. [you know, since he probably never tinkered with electronics when he was a kid and asked someone for advice] = sarcasm i'm slightly disappointed in him. a grown man, who attacks eager to learn children over the internet. do you not have friends? a life? besides if you don't help people, but instead show them hostility, don't you think they may become discouraged? maybe even give it up and quit? if there is no one interested in this type of engineering, then it may cease to exist. all i'm saying is, be an encourager, help others, and go with god. "since new developments are the products of a creative mind, we must therefore stimulate and ENCOURAGE that type of mind in every way possible." -george washington carver sorry to be so short, and thanks to everyone who tried to help, taylor Oh no! Another victim! This time it is an alleged kid. I thought everybody gave him plenty of good, free advice. Hummm. . . Being "Short", huh? Short would have been simply "Go jump in the lake, Buddy!" Hehehehe FFF |
#6
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"David G. Nagel" wrote in message
... FCC part 15 regulations specify that a low power am transmitter can not exceed a very low power level ( I don't remember off hand how much) http://www.access.gpo.gov/nara/cfr/w...7cfr15_06.html PART 15_RADIO FREQUENCY DEVICES--Table of Contents Subpart C_Intentional Radiators Sec. 15.219 Operation in the band 510-1705 kHz. (a) The total input power to the final radio frequency stage (exclusive of filament or heater power) shall not exceed 100 milliwatts. and the antenna must be attached to the transmitter and must not exceed about 5 or 6 feet.(b) The total length of the transmission line, antenna and ground lead (if used) shall not exceed 3 meters. |
#7
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"John" wrote in message
... The last paragraph of my post got munged. It should be: and the antenna must be attached to the transmitter and must not exceed about 5 or 6 feet. (b) The total length of the transmission line, antenna and ground lead (if used) shall not exceed 3 meters. |
#8
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John wrote:
"David G. Nagel" wrote in message ... FCC part 15 regulations specify that a low power am transmitter can not exceed a very low power level ( I don't remember off hand how much) http://www.access.gpo.gov/nara/cfr/w...7cfr15_06.html PART 15_RADIO FREQUENCY DEVICES--Table of Contents Subpart C_Intentional Radiators Sec. 15.219 Operation in the band 510-1705 kHz. (a) The total input power to the final radio frequency stage (exclusive of filament or heater power) shall not exceed 100 milliwatts. and the antenna must be attached to the transmitter and must not exceed about 5 or 6 feet.(b) The total length of the transmission line, antenna and ground lead (if used) shall not exceed 3 meters. Thank you for the information. This is something I know but not in intimate detail. This is what the student was looking for but the dark side of the net had to have it's way with the subject. I hope it helps the student with his science project. Dave Nagel WD9BDZ |
#9
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On Sat, 10 Feb 2007 12:06:06 -0600, "David G. Nagel"
wrote: I hope it helps the student with his science project. Hi Dave, That is of infinite improbability. How many times do we have to tell adult amateur radio enthusiasts the necessity of matching (a warning already offered from the shadows of this thread)? So, shall we consider the merit of a total length of 3 meters in the AM band? If this discussion is so studiously avoided by those who weep away about the dearth of information, what chance does a naive student have to rummage up the details? The Rr summons up to roughly 20mOhms. Are any of the scolds going to offer the implications of this value? Are there any suggestions of using commercial tower sections to cut down on Ohmic loss? Any matching details for the massive SWR? Any hints on how to load the structure? Details for a top hat? Would the top hat consume part of that 3 meter restriction? Would a loop perform better? What dimensions? How to build the capacitors? Talk about underwhelming help.... the dark side of the net had to have it's way with the subject. The dark side is not patronizing with soothing but impotent nostrums. The topic reduces to one of two resolutions: 1. Deep consideration of many issues; 2. Buy a kit that works as advertised. One takes many here a lifetime of consideration and books are devoted to this study, the other satisfies a need. 73's Richard Clark, KB7QHC |
#10
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Richard Clark wrote:
On Sat, 10 Feb 2007 12:06:06 -0600, "David G. Nagel" wrote: I hope it helps the student with his science project. Hi Dave, That is of infinite improbability. How many times do we have to tell adult amateur radio enthusiasts the necessity of matching (a warning already offered from the shadows of this thread)? So, shall we consider the merit of a total length of 3 meters in the AM band? If this discussion is so studiously avoided by those who weep away about the dearth of information, what chance does a naive student have to rummage up the details? The Rr summons up to roughly 20mOhms. Are any of the scolds going to offer the implications of this value? Are there any suggestions of using commercial tower sections to cut down on Ohmic loss? Any matching details for the massive SWR? Any hints on how to load the structure? Details for a top hat? Would the top hat consume part of that 3 meter restriction? Richard, I dare say that the 3 meter limit, and the horrible mismatch achieved with such an antenna just might be part of the whole idea of part 15 transmission. The user isn't supposed to put much of a signal on the air. It's supposed to be a technically poor setup. Of course, assuming that the science fair is taking place in a school building, the student could operate as a campus transmitter. Lots of extra steps and paperwork there though. Would a loop perform better? What dimensions? How to build the capacitors? Talk about underwhelming help.... Seems like a good way to go for the kid would be to buy a kit or better, build a radio from scratch, keeping within the legal limits. Asking for help in here can be confusing enough for a new Ham, let alone a young schoolkid. the dark side of the net had to have it's way with the subject. I have these visions of you making Darth Vader sounds, and saying "I...am your father T."...... 8^) - 73 de Mike KB3EIA - |
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