I'm looking for plans for a simple AM antenna to connect to my stereo to
replace the little loop antenna that came with it. In the past I have
used long wires but they are not very directional.

"not very directional"
A loop will have figure 8 pattern with sharp nulls on axis (both sides)

Long wires aren not very directional.


I have found some fairly good plans online

How about posting the URL.

In no particular order. . .

http://www.mindspring.com/~loop_antenna/
http://www.dxzone.com/catalog/Antennas/Loop/
http://www.mtmscientific.com/loop.html
http://www.frontiernet.net/~jadale/Loop.htm
http://www.dxzone.com/catalog/Antennas/Shortwave/
http://www.schmarder.com/radios/misc-stuff/loops.htm



for what looks like wire wound around a box but all of them seem to have
potentiometer in the mix somewhere. It would be very little problem to
build an aimable 18 to even 48 inch frame.

"seem to have potentiometer in the mix somewhere."
I think you mean a variable capacitor.

One or the other depending on the plans


I only have two AM stations I'd like to come in clearer (690 KHz and 1440
KHz). Would it be possible to make a 'box' with one 'tap' for 690 and
one for 1440 then just connect one or the other the radio? How long
would be wires need to be and how would I feed it into the connections on
the radio (coax)?
A tap could be done but I think it would be difficult to find the proper
position.
A better way would be to use a switch with two different tuning
capacitors. You
could have the smaller value fixed in the circuit (for 1440) then close a
switch
to put the second larger value in parallel to tune 690 khz.
If the stations are 90 degrees from each other at your location, you
might find one station
in the null of you antenna.

I think a simple measurement would do it. For 690KHz you could tap it at
1425 feet or at any fraction thereof. For 1440KHz you just use 919 feet.

That was my original plan. To take a 4 foot square frame and put 22 winds
of wire on it. That would give me about 1/4 of a wavelenght of 690. I
could put a tap at the 14th winding to give me a 1/4 wavelenght for 1440.

Mike

no spam wrote:
Long wires aren't not very directional.

From Wikipedia: "The Beverage Antenna is an inexpensive
*long wire* receiving antenna ... Beverage antennas are
*highly directional.*
--
73, Cecil, w5dxp.com

Cecil, W5DXP wrote:
"Beverage antennas are highly directional."

Living in Portugal in the 1950`s, I used a Beverage antenna to listen to
the CBS Evening News from WCBS in New York, and WWL in New Orleans.
Whenever one station faded, I just rocked the dial and the other station
would be there. Portugal is on Greenwich time so the Evening News was
around midnight local time. By then, most of the Europeans had signed
off.

All you must have for a Beverage antenna is a long wire, say 2
wavelengths long, aimed at the targeted broadcaster.

Best regards, Richard Harrison, KB5WZI

"Beverage antennas are highly directional."

Living in Portugal in the 1950`s, I used a Beverage antenna to listen to
the CBS Evening News from WCBS in New York, and WWL in New Orleans.
Whenever one station faded, I just rocked the dial and the other station
would be there. Portugal is on Greenwich time so the Evening News was
around midnight local time. By then, most of the Europeans had signed
off.

All you must have for a Beverage antenna is a long wire, say 2
wavelengths long, aimed at the targeted broadcaster.

For 690 KHz that would be 2,850 feet of wire, just over 1/2 a mile of wire.

"no spam" ) writes:
"Beverage antennas are highly directional."

Living in Portugal in the 1950`s, I used a Beverage antenna to listen to
the CBS Evening News from WCBS in New York, and WWL in New Orleans.
Whenever one station faded, I just rocked the dial and the other station
would be there. Portugal is on Greenwich time so the Evening News was
around midnight local time. By then, most of the Europeans had signed
off.

All you must have for a Beverage antenna is a long wire, say 2
wavelengths long, aimed at the targeted broadcaster.

For 690 KHz that would be 2,850 feet of wire, just over 1/2 a mile of wire.


WHen he said "all you need" I was tempted to add "and space for that antenna".

Of course, some people are lucky. You do hear of people doing really well
with really long wire antennas, and presumably they have such great success
because few have the space to have similar antennas.

There was a guy in Australia forty years ago, Ray Knaughton (I'm sure
I've misspelled that), who did moonbounce with rhombic antennas. He
lived in the outback, so he had the space. Got enough gain to overcome
Australia's 150W power limit at the time (I think it was that low). He
had enough space for putting up high gain rhombics for various VHF bands.
The big problem was that since they weren't steerable, he had a big limit
on when he could do moonbounce, since the moon wasn't in the right place
most of the time.

Michael VE2BVW

Living in Portugal in the 1950`s, I used a Beverage antenna to listen to
the CBS Evening News from WCBS in New York, and WWL in New Orleans.
Whenever one station faded, I just rocked the dial and the other station
would be there. Portugal is on Greenwich time so the Evening News was
around midnight local time. By then, most of the Europeans had signed
off.

All you must have for a Beverage antenna is a long wire, say 2
wavelengths long, aimed at the targeted broadcaster.

For 690 KHz that would be 2,850 feet of wire, just over 1/2 a mile of
wire.


WHen he said "all you need" I was tempted to add "and space for that
antenna".

Of course, some people are lucky. You do hear of people doing really well
with really long wire antennas, and presumably they have such great
success
because few have the space to have similar antennas.

In TN I had 25 acres and ran a 200+ ft long wire which was enough to pick up
the Nashville stations. I once connected my antenna to the electric fence
wire (after disconnecting the charger) that ran around about 1/2 of the
place. Didn't do much.

Here I have 16 acres which means I could, in theory, run about 2,000 ft of
wire. Still I was thinking of something a little smaller.

no spam wrote:
"For 690 KHz that would be 2850 feet of wire, just over 1/2 mile of
wire."

Something like that. The site was a shortwave broadcast plant that had a
rhombic aimed at New York for last ditch program relay in case all else
failed. It was located at a far corner of many acres to be well out of
the shortwave field. As we were not last ditching it, I borrowed its
open wire transmission line, shorted it and fed it to my medium wave
receiver. It worked like a champ.

Best regards, Richard Harrison, KB5WZI