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.

I have found some fairly good plans online 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.

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)?

On Wed, 09 May 2007 17:35:31 GMT, "no spam" wrote:

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.

I have found some fairly good plans online 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.

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)?


The simplest would be to find a variable capacitor from a derelict
radio. The tuning range and size will force you to build the right
size coil - which is vastly simpler to building the coil first and
then finding the right variable capacitor. Using a cap from a
derelict radio will give you the right minimum to maximum range
variation (often with a max in the region of 360 pF just in case you
cannot find a derelict radio). With the capacitor in its maximum mesh
(or nearly so), you wind the box antenna until you find enough
windings to peak the lowest frequency signal. The upper frequency
signal should also peak when you open up the meshed plates. Mark the
two peaks' positions of the variable cap's knob setting.

To couple to the antenna, construct, or simple extend the existing
loop of your current radio to fit inside the box antenna.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote in message
...
On Wed, 09 May 2007 17:35:31 GMT, "no spam" wrote:

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.

I have found some fairly good plans online 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.

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)?


The simplest would be to find a variable capacitor from a derelict
radio. The tuning range and size will force you to build the right
size coil - which is vastly simpler to building the coil first and
then finding the right variable capacitor. Using a cap from a
derelict radio will give you the right minimum to maximum range
variation (often with a max in the region of 360 pF just in case you
cannot find a derelict radio). With the capacitor in its maximum mesh
(or nearly so), you wind the box antenna until you find enough
windings to peak the lowest frequency signal. The upper frequency
signal should also peak when you open up the meshed plates. Mark the
two peaks' positions of the variable cap's knob setting.

Simple for you. My electronic education is limited to some high school and
college physics and some 'playing' on my on. IOW, I know a cap isn't
something you wear on your head but 'maximum mesh' sounds like either the
gears in your transmission are working very well or your girl friend is
wearing something sexy.

On Thu, 10 May 2007 14:54:03 GMT, "no spam" wrote:

Simple for you. My electronic education is limited to some high school and
college physics and some 'playing' on my on. IOW, I know a cap isn't
something you wear on your head but 'maximum mesh' sounds like either the
gears in your transmission are working very well or your girl friend is
wearing something sexy.

Sorry about your limitations. Sounds like you will have some
difficulty.

73's
Richard Clark, KB7QHC

That is really simple cap=capacitor mesh=how much the plates overlap
On May 10, 7:54 am, "no spam" wrote:
"Richard Clark" wrote in message

...





On Wed, 09 May 2007 17:35:31 GMT, "no spam" wrote:

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.

I have found some fairly good plans online 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.

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)?

The simplest would be to find a variable capacitor from a derelict
radio. The tuning range and size will force you to build the right
size coil - which is vastly simpler to building the coil first and
then finding the right variable capacitor. Using a cap from a
derelict radio will give you the right minimum to maximum range
variation (often with a max in the region of 360 pF just in case you
cannot find a derelict radio). With the capacitor in its maximum mesh
(or nearly so), you wind the box antenna until you find enough
windings to peak the lowest frequency signal. The upper frequency
signal should also peak when you open up the meshed plates. Mark the
two peaks' positions of the variable cap's knob setting.

Simple for you. My electronic education is limited to some high school and
college physics and some 'playing' on my on. IOW, I know a cap isn't
something you wear on your head but 'maximum mesh' sounds like either the
gears in your transmission are working very well or your girl friend is
wearing something sexy.- Hide quoted text -

- Show quoted text -

"no spam" wrote in message
news
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)

I have found some fairly good plans online

How about posting the URL.

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.

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.
Mike

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.