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.

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

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

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

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

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.

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

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

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

Taylor 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. --------"

The information is sparse but may be enough.

Kits are available for low-powered transmitters which are restricted by
law to a short wire antenna to avoid harmful interference.

My experience is that this is adequate. The receiving antenna is almost
unrestricted. It may extend to closely couple with the transmitting
antenna, though this is rarely required.

Most receivers are capable of receiving a very weak signal which means
the receiving antenna can be distant from the transmitting antenna.

A transmitted signal propagating in free space loses 22 dB in its first
wavelength of travel from the transmitting antenna, 300 meters at 1 MHz,
and then loses an additional 6 dB every time the distance from the
transmitting antenna doubles after that.

So, the tiny phono oscillator with almost no antenna can be heard at a
considerable distance.

Best regards, Richard Harrison, KB5WZI