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Old February 7th 07, 04:55 AM posted to rec.radio.amateur.antenna
T T is offline
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Default Science Fair Project

i'm working on a science fair project. i'm building an am-radio
transmitter. i can only be a few inches from the receiver. how do i
solve this problem without making my antenna enormous.

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Old February 7th 07, 07:46 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

On 6 Feb 2007 20:55:20 -0800, "T" wrote:

i'm working on a science fair project. i'm building an am-radio
transmitter. i can only be a few inches from the receiver. how do i
solve this problem without making my antenna enormous.


Build a loop stick antenna (Google the term).

73's
Richard Clark, KB7QHC
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Old February 7th 07, 11:46 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

Or use fine wire to build a larger multi-turn loop antenna into the
perimeter of the "story-board" for your science fair display. If this is
truly a science fair project, then the antenna is an important part of the
story that should be shown, isn't it?

Joe
W3JDR


"Richard Clark" wrote in message
...
On 6 Feb 2007 20:55:20 -0800, "T" wrote:

i'm working on a science fair project. i'm building an am-radio
transmitter. i can only be a few inches from the receiver. how do i
solve this problem without making my antenna enormous.


Build a loop stick antenna (Google the term).

73's
Richard Clark, KB7QHC



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Old February 8th 07, 02:45 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

will this boost my transmitter's signal, or the reciever's antenna?

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Old February 8th 07, 03:18 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

On 7 Feb 2007 18:45:29 -0800, T posted in total:

will this boost my transmitter's signal, or the reciever's antenna?



Will _what_ boost _what_ transmitter's 'signal'????

What is a "reciever"?

Oh, I see:
Message-ID: . com


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Old February 8th 07, 05:34 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

On Feb 7, 6:45 pm, "T" wrote:
will this boost my transmitter's signal, or the reciever's antenna?


Um, if you connect the better antenna to the transmitter, how would
that affect the receiver? If you connect the better antenna to the
receiver, how would that affect the transmitter? Clear?

Cheers,
Tom

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Old February 9th 07, 02:07 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

On 6 Feb, 20:55, "T" wrote:
i'm working on a science fair project. i'm building an am-radio
transmitter. i can only be a few inches from the receiver. how do i
solve this problem without making my antenna enormous.


If you build an amplifier at the initial recerving antenna which is
preferably
outside the house the signal within the coax leading to and within
the house
will be strong enought to overcome the losses entailed by using a
long
connecting coax. Placing the amplifier at the antenna prevents noise
from
overpowering the incomming signal The amplifier need only to be a
simple
transister driven by a battery. Remember that the signal to noise
ratio will
never be better than the signal recieved by your antenna before
amplification
which should provide the impetus to build the best antenna you can
build
and situated in the most desirable place for receiving..
Good luck
Art

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Old February 9th 07, 02:39 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

On Feb 8, 8:07 pm, "art" wrote:
On 6 Feb, 20:55, "T" wrote:

i'm working on a science fair project. i'm building an am-radio
transmitter. i can only be a few inches from the receiver. how do i
solve this problem without making my antenna enormous.


Placing the amplifier at the antenna prevents noise
from
overpowering the incomming signal The amplifier need only to be a
simpleIf you build an amplifier at the initial recerving antenna which is
preferably
outside the house the signal within the coax leading to and within
the house
will be strong enought to overcome the losses entailed by using a
long
connecting coax.


I think he means the AM broadcast band.. Or I assume anyway.
The loss with most any length of coax at that MW freq should be
dinky indeed.
I built one of those when I was about in 7th grade. Mine had like
a small tight wound loop for an antenna if I remember right. But I
might
have even tried hooking it to to my then SWL antenna which was a 50
ft random wire. I don't know how critical the transister? is as far as
match. If it's not picky, you could probably just string out a short
wire. There are probably FCC antenna standards as far as such a
device,
but I'm too lazy to look them up.. I don't think the FCC wants them
radiating too far. As far as receiving at MW, Any commercial radio
should be good enough with whatever antenna came with it.
Well, unless it's a really lousy radio.. If you can hear noise
in between stations in the daytime, it's good enough and can't really
be
improved too much as far as s/n ratio.
MK


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Old February 9th 07, 04:12 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

On Feb 7, 9:18 pm, Nobody wrote:
On 7 Feb 2007 18:45:29 -0800, T posted in total:

will this boost my transmitter's signal, or the reciever's antenna?


Will _what_ boost _what_ transmitter's 'signal'????

What is a "reciever"?



ok. let me be more clear. my transmitter is a simple am-radio
transmitter. it is essentially an aduio transformer connected to a
1mhz crystal oscillator. i have, connected to my oscillator's antenna
lead, a simple telescoping radio antenna, and so my "transmitter"----
[the am-radio transmitter] has to be just a few inches from my
"reciever" ----[the am-radio] for the "reciever" to pick up my
signal.

My question is: will this antenna, the loop stick antenna mentioned
above, boost the signal coming from my "transmitter" or will it just
allow my reciever to pick up the signal easier? or in other words how
will this antenna help me?

sorry if i wasn't clear enough before. i just thought you would
understand what i was talking about.

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Old February 9th 07, 06:34 AM posted to rec.radio.amateur.antenna
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Default Science Fair Project

On 8 Feb 2007 20:12:15 -0800, "T" wrote:

My question is: will this antenna, the loop stick antenna mentioned
above, boost the signal coming from my "transmitter" or will it just
allow my reciever to pick up the signal easier? or in other words how
will this antenna help me?


No one can tell how anything can help if you don't tell us what help
you need.

Being able to receive inches away speaks to an accomplishment, not a
problem. If you want to receive miles away, then the comparison
between what is accomplished and what is desired reveals the problem.

sorry if i wasn't clear enough before. i just thought you would
understand what i was talking about.


You never really "talked about" anything when the sum total of your
correspondence barely exceeds a half dozen lines up to this posting.

Now, we can all presume an intent, and that intent goes counter to
what is allowed by law, and that is long distance communication on
commercial frequencies by an unlicensed station. The law is
exceptionally clear as to how much power is allowed, into how large a
radiator, for unlicensed stations (such as yours). The long and short
of it is that without exceptionally good reception gear, that distance
is rarely more than across the room, or within a block.

Clearly, even these distances vastly exceed your current
accomplishment of a few inches because you could invest little more
effort into doing it with a modulated LED across the room. TV remotes
do this a billion times an hour world-wide.

Even with the allowed sized radiator, it is pathetically inefficient
(which is the intent of the law). The name of the game is called
matching, and a XTAL oscillator is a poor power source.

However, all of this is strictly window dressing unless the whole
scope of your Science Fair project is limited to building a working
transmitter. If so, you need to formulate better questions. If not,
you are spending too much time when you could build a Ramsey Kit in an
afternoon and get on with the grist of the project.

73's
Richard Clark, KB7QHC
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