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ric
 
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Robert Morein wrote:

Are you familiar with the FM2G-C? It is being strongly considered.

http://www.fanfare.com/fm-2g-c.html


This is an omnidirectional antenna, which means it will be very susceptible
to multipath. The fact that it is cut for the educational band gives it a
little more gain, but, as I said, gain is seldom the problem. The problem is
phase cancellation caused by reception of a signal that is reflected by two
or more different paths. This causes the signal to actually cancel 100% at
certain frequencies. More gain on nothing does not result in something. The
solution is a directional antenna, which attenuates all but one of the
reception paths, eliminating the phase cancellation.


Hmmm...I'm getting a slew of opinions on this, and few of them reach
the same conclusion. Such as:

http://www.hawaiipublicradio.org/recep.htm

I've tried various dipole antennas, all with similar results. Best
results so far was an RCA powered indoor TV "rabbit ear" type antenna.

I'm tempted to have an antenna cut specifically for 88.3 MHz, as that is
the only FM I listen to. Oh well...
  #2   Report Post  
Robert Morein
 
Posts: n/a
Default


"ric" wrote in message ...
Robert Morein wrote:

Are you familiar with the FM2G-C? It is being strongly considered.

http://www.fanfare.com/fm-2g-c.html


This is an omnidirectional antenna, which means it will be very

susceptible
to multipath. The fact that it is cut for the educational band gives it

a
little more gain, but, as I said, gain is seldom the problem. The

problem is
phase cancellation caused by reception of a signal that is reflected by

two
or more different paths. This causes the signal to actually cancel 100%

at
certain frequencies. More gain on nothing does not result in something.

The
solution is a directional antenna, which attenuates all but one of the
reception paths, eliminating the phase cancellation.


Hmmm...I'm getting a slew of opinions on this, and few of them reach
the same conclusion. Such as:

http://www.hawaiipublicradio.org/recep.htm

I've tried various dipole antennas, all with similar results. Best
results so far was an RCA powered indoor TV "rabbit ear" type antenna.

I'm tempted to have an antenna cut specifically for 88.3 MHz, as that is
the only FM I listen to. Oh well...


You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2 that
length: 33.5. All you need is a piece of twinlead, which is just junky
antenna lead-in wire. Cut it to 33.5 inches. At each end, twist the
conductors together. At the center, break one conductor. Connect the loose
ends to your feed wire. It is not essential, but nice, if you can have t the
connections soldered. Protect the wires from bending and breaking by
encasing the joints in some RTV (GE silicone goo).

I do not understand why the station engineer recommended the Fanfare. This
antenna has 0 dB gain. 0 is a very small number. The only advantage to the
Fanfare is for external use, since it is self-supporting. An indoor dipole,
which can be taped or tacked to any convenient surface, does not need
mechanical rigidity.

A properly cut dipole has twice the signal strength: 3 dB.



  #3   Report Post  
Margaret von B.
 
Posts: n/a
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"Robert Morein" wrote in message
...

"ric" wrote in message
...
Robert Morein wrote:

Are you familiar with the FM2G-C? It is being strongly considered.

http://www.fanfare.com/fm-2g-c.html

This is an omnidirectional antenna, which means it will be very

susceptible
to multipath. The fact that it is cut for the educational band gives it

a
little more gain, but, as I said, gain is seldom the problem. The

problem is
phase cancellation caused by reception of a signal that is reflected by

two
or more different paths. This causes the signal to actually cancel 100%

at
certain frequencies. More gain on nothing does not result in something.

The
solution is a directional antenna, which attenuates all but one of the
reception paths, eliminating the phase cancellation.


Hmmm...I'm getting a slew of opinions on this, and few of them reach
the same conclusion. Such as:

http://www.hawaiipublicradio.org/recep.htm

I've tried various dipole antennas, all with similar results. Best
results so far was an RCA powered indoor TV "rabbit ear" type antenna.

I'm tempted to have an antenna cut specifically for 88.3 MHz, as that is
the only FM I listen to. Oh well...


You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2 that
length: 33.5. All you need is a piece of twinlead, which is just junky
antenna lead-in wire. Cut it to 33.5 inches. At each end, twist the
conductors together. At the center, break one conductor. Connect the loose
ends to your feed wire. It is not essential, but nice, if you can have t
the
connections soldered. Protect the wires from bending and breaking by
encasing the joints in some RTV (GE silicone goo).

I do not understand why the station engineer recommended the Fanfare.


I do. It worked in his location.

This
antenna has 0 dB gain. 0 is a very small number. The only advantage to the
Fanfare is for external use, since it is self-supporting. An indoor
dipole,
which can be taped or tacked to any convenient surface, does not need
mechanical rigidity.

A properly cut dipole has twice the signal strength: 3 dB.




There's more to antennas than theory, especially these "little ones". As I
stated before, I don't have any experience of this particular antenna but I
have plenty of experience of seemingly similar design, The Magnum Dynalab
ST-2.

http://www.magnumdynalab.com/x_st2.htm

It has worked admirably well over the years in many urban locations except
one. NYC RF hell rendered it pretty much useless. However, at the time I did
not have the Signal Sleuth that greatly complements the whip albeit at a
considerable cost.

http://www.magnumdynalab.com/x_sleuth.htm

Based on my "nontechnical" opinion I can say that the whip alone generally
outperforms the "grocerybagful" of dipoles I've accumulated over the years
by a comfortable margin. With the Sleuth, it is the ultimate quick and small
FM antenna solution. One of my favorite tuners has a scope that allows the
monitoring of multipath signals and contrary to what one might think, the
ST-2 is not all that easily bothered by it. That said, there are locations,
such as NYC, where the cheap but nearly unobtainable Dennesen dual whip
cannot be beat. I suspect that the Dennesen would be an easy DIY project for
those so inclined.

But no one should fool themselves into thinking that any of these products
will succesfully compete with a competent outdoor antenna such as those
made by APS.

Cheers,

Margaret


















  #4   Report Post  
Robert Morein
 
Posts: n/a
Default


"Margaret von B." wrote in message
...

"Robert Morein" wrote in message
...

"ric" wrote in message
...
Robert Morein wrote:

Are you familiar with the FM2G-C? It is being strongly considered.

http://www.fanfare.com/fm-2g-c.html

This is an omnidirectional antenna, which means it will be very

susceptible
to multipath. The fact that it is cut for the educational band gives

it
a
little more gain, but, as I said, gain is seldom the problem. The

problem is
phase cancellation caused by reception of a signal that is reflected

by
two
or more different paths. This causes the signal to actually cancel

100%
at
certain frequencies. More gain on nothing does not result in

something.
The
solution is a directional antenna, which attenuates all but one of

the
reception paths, eliminating the phase cancellation.

Hmmm...I'm getting a slew of opinions on this, and few of them reach
the same conclusion. Such as:

http://www.hawaiipublicradio.org/recep.htm

I've tried various dipole antennas, all with similar results. Best
results so far was an RCA powered indoor TV "rabbit ear" type antenna.

I'm tempted to have an antenna cut specifically for 88.3 MHz, as that

is
the only FM I listen to. Oh well...


You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2

that
length: 33.5. All you need is a piece of twinlead, which is just junky
antenna lead-in wire. Cut it to 33.5 inches. At each end, twist the
conductors together. At the center, break one conductor. Connect the

loose
ends to your feed wire. It is not essential, but nice, if you can have t
the
connections soldered. Protect the wires from bending and breaking by
encasing the joints in some RTV (GE silicone goo).

I do not understand why the station engineer recommended the Fanfare.


I do. It worked in his location.

This
antenna has 0 dB gain. 0 is a very small number. The only advantage to

the
Fanfare is for external use, since it is self-supporting. An indoor
dipole,
which can be taped or tacked to any convenient surface, does not need
mechanical rigidity.

A properly cut dipole has twice the signal strength: 3 dB.




There's more to antennas than theory, especially these "little ones". As I
stated before, I don't have any experience of this particular antenna but

I
have plenty of experience of seemingly similar design, The Magnum Dynalab
ST-2.

http://www.magnumdynalab.com/x_st2.htm

It has worked admirably well over the years in many urban locations except
one. NYC RF hell rendered it pretty much useless. However, at the time I

did
not have the Signal Sleuth that greatly complements the whip albeit at a
considerable cost.

http://www.magnumdynalab.com/x_sleuth.htm

Based on my "nontechnical" opinion I can say that the whip alone generally
outperforms the "grocerybagful" of dipoles I've accumulated over the years
by a comfortable margin. With the Sleuth, it is the ultimate quick and

small
FM antenna solution. One of my favorite tuners has a scope that allows the
monitoring of multipath signals and contrary to what one might think, the
ST-2 is not all that easily bothered by it. That said, there are

locations,
such as NYC, where the cheap but nearly unobtainable Dennesen dual whip
cannot be beat. I suspect that the Dennesen would be an easy DIY project

for
those so inclined.

But no one should fool themselves into thinking that any of these products
will succesfully compete with a competent outdoor antenna such as those
made by APS.

Cheers,

Margaret

Margaret, without contradicting your experience, I think that the difference
in sound has to do with the placement of the antenna. Perhaps the
freestanding whip was placeable in a way that the dipole was not.
The real solution comes from an antenna arrangement with some
directionality. If the multipath signal(s) can be reduced below one
particular strongest signal, then phase cancellation cannot occur. Two whips
separated by 1/2 wavelength can be directionally oriented by a combining
phase shift network, which is probably why your Dennesen worked so well.
A single vertical whip receives equally well from all directions. This means
that reduction in multipath can be accomplished only by moving the antenna
about the room. By contrast, a dipole can be rotated through 180 vertically,
and 180 degrees horizontally, while in the same location, provided one can
find a way to support the floppy wires. Taping it to a dowell stick would
work.


  #5   Report Post  
Margaret von B.
 
Posts: n/a
Default


"Robert Morein" wrote in message
...

"Margaret von B." wrote in message
...

"Robert Morein" wrote in message
...

"ric" wrote in message
...
Robert Morein wrote:

Are you familiar with the FM2G-C? It is being strongly considered.

http://www.fanfare.com/fm-2g-c.html

This is an omnidirectional antenna, which means it will be very
susceptible
to multipath. The fact that it is cut for the educational band gives

it
a
little more gain, but, as I said, gain is seldom the problem. The
problem is
phase cancellation caused by reception of a signal that is reflected

by
two
or more different paths. This causes the signal to actually cancel

100%
at
certain frequencies. More gain on nothing does not result in

something.
The
solution is a directional antenna, which attenuates all but one of

the
reception paths, eliminating the phase cancellation.

Hmmm...I'm getting a slew of opinions on this, and few of them reach
the same conclusion. Such as:

http://www.hawaiipublicradio.org/recep.htm

I've tried various dipole antennas, all with similar results. Best
results so far was an RCA powered indoor TV "rabbit ear" type antenna.

I'm tempted to have an antenna cut specifically for 88.3 MHz, as that

is
the only FM I listen to. Oh well...

You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2

that
length: 33.5. All you need is a piece of twinlead, which is just junky
antenna lead-in wire. Cut it to 33.5 inches. At each end, twist the
conductors together. At the center, break one conductor. Connect the

loose
ends to your feed wire. It is not essential, but nice, if you can have
t
the
connections soldered. Protect the wires from bending and breaking by
encasing the joints in some RTV (GE silicone goo).

I do not understand why the station engineer recommended the Fanfare.


I do. It worked in his location.

This
antenna has 0 dB gain. 0 is a very small number. The only advantage to

the
Fanfare is for external use, since it is self-supporting. An indoor
dipole,
which can be taped or tacked to any convenient surface, does not need
mechanical rigidity.

A properly cut dipole has twice the signal strength: 3 dB.




There's more to antennas than theory, especially these "little ones". As
I
stated before, I don't have any experience of this particular antenna but

I
have plenty of experience of seemingly similar design, The Magnum Dynalab
ST-2.

http://www.magnumdynalab.com/x_st2.htm

It has worked admirably well over the years in many urban locations
except
one. NYC RF hell rendered it pretty much useless. However, at the time I

did
not have the Signal Sleuth that greatly complements the whip albeit at a
considerable cost.

http://www.magnumdynalab.com/x_sleuth.htm

Based on my "nontechnical" opinion I can say that the whip alone
generally
outperforms the "grocerybagful" of dipoles I've accumulated over the
years
by a comfortable margin. With the Sleuth, it is the ultimate quick and

small
FM antenna solution. One of my favorite tuners has a scope that allows
the
monitoring of multipath signals and contrary to what one might think, the
ST-2 is not all that easily bothered by it. That said, there are

locations,
such as NYC, where the cheap but nearly unobtainable Dennesen dual whip
cannot be beat. I suspect that the Dennesen would be an easy DIY project

for
those so inclined.

But no one should fool themselves into thinking that any of these
products
will succesfully compete with a competent outdoor antenna such as those
made by APS.

Cheers,

Margaret

Margaret, without contradicting your experience, I think that the
difference
in sound has to do with the placement of the antenna.


That's probably most of it. As I said, "there's more than theory"...

Perhaps the
freestanding whip was placeable in a way that the dipole was not.
The real solution comes from an antenna arrangement with some
directionality. If the multipath signal(s) can be reduced below one
particular strongest signal, then phase cancellation cannot occur. Two
whips
separated by 1/2 wavelength can be directionally oriented by a combining
phase shift network, which is probably why your Dennesen worked so well.


It still works, if I can stand to look at it. :-) However, my primary
residence sports a Sniper these days with Yaesu rotor.

A single vertical whip receives equally well from all directions. This
means
that reduction in multipath can be accomplished only by moving the antenna
about the room. By contrast, a dipole can be rotated through 180
vertically,
and 180 degrees horizontally, while in the same location, provided one can
find a way to support the floppy wires. Taping it to a dowell stick would
work.



I hear you, but when using an A/B switch and watching the trace as you
switch antennas, any changes in multipath reception are easily detected.
Using such setup, I can only conclude that the ST-2, generally speaking, is
not impeded by multipath reception and will deliver a stronger, cleaner
signal to a tuner than a R/S dipole and its cousins.


Cheers,

Margaret







  #6   Report Post  
Robert Morein
 
Posts: n/a
Default


"Margaret von B." wrote in message
news

"Robert Morein" wrote in message
...

"Margaret von B." wrote in message
...

"Robert Morein" wrote in message
...

"ric" wrote in message
...
Robert Morein wrote:

Are you familiar with the FM2G-C? It is being strongly

considered.

http://www.fanfare.com/fm-2g-c.html

This is an omnidirectional antenna, which means it will be very
susceptible
to multipath. The fact that it is cut for the educational band

gives
it
a
little more gain, but, as I said, gain is seldom the problem. The
problem is
phase cancellation caused by reception of a signal that is

reflected
by
two
or more different paths. This causes the signal to actually cancel

100%
at
certain frequencies. More gain on nothing does not result in

something.
The
solution is a directional antenna, which attenuates all but one of

the
reception paths, eliminating the phase cancellation.

Hmmm...I'm getting a slew of opinions on this, and few of them reach
the same conclusion. Such as:

http://www.hawaiipublicradio.org/recep.htm

I've tried various dipole antennas, all with similar results. Best
results so far was an RCA powered indoor TV "rabbit ear" type

antenna.

I'm tempted to have an antenna cut specifically for 88.3 MHz, as

that
is
the only FM I listen to. Oh well...

You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2

that
length: 33.5. All you need is a piece of twinlead, which is just

junky
antenna lead-in wire. Cut it to 33.5 inches. At each end, twist the
conductors together. At the center, break one conductor. Connect the

loose
ends to your feed wire. It is not essential, but nice, if you can

have
t
the
connections soldered. Protect the wires from bending and breaking by
encasing the joints in some RTV (GE silicone goo).

I do not understand why the station engineer recommended the Fanfare.

I do. It worked in his location.

This
antenna has 0 dB gain. 0 is a very small number. The only advantage

to
the
Fanfare is for external use, since it is self-supporting. An indoor
dipole,
which can be taped or tacked to any convenient surface, does not need
mechanical rigidity.

A properly cut dipole has twice the signal strength: 3 dB.




There's more to antennas than theory, especially these "little ones".

As
I
stated before, I don't have any experience of this particular antenna

but
I
have plenty of experience of seemingly similar design, The Magnum

Dynalab
ST-2.

http://www.magnumdynalab.com/x_st2.htm

It has worked admirably well over the years in many urban locations
except
one. NYC RF hell rendered it pretty much useless. However, at the time

I
did
not have the Signal Sleuth that greatly complements the whip albeit at

a
considerable cost.

http://www.magnumdynalab.com/x_sleuth.htm

Based on my "nontechnical" opinion I can say that the whip alone
generally
outperforms the "grocerybagful" of dipoles I've accumulated over the
years
by a comfortable margin. With the Sleuth, it is the ultimate quick and

small
FM antenna solution. One of my favorite tuners has a scope that allows
the
monitoring of multipath signals and contrary to what one might think,

the
ST-2 is not all that easily bothered by it. That said, there are

locations,
such as NYC, where the cheap but nearly unobtainable Dennesen dual whip
cannot be beat. I suspect that the Dennesen would be an easy DIY

project
for
those so inclined.

But no one should fool themselves into thinking that any of these
products
will succesfully compete with a competent outdoor antenna such as

those
made by APS.

Cheers,

Margaret

Margaret, without contradicting your experience, I think that the
difference
in sound has to do with the placement of the antenna.


That's probably most of it. As I said, "there's more than theory"...

Perhaps the
freestanding whip was placeable in a way that the dipole was not.
The real solution comes from an antenna arrangement with some
directionality. If the multipath signal(s) can be reduced below one
particular strongest signal, then phase cancellation cannot occur. Two
whips
separated by 1/2 wavelength can be directionally oriented by a combining
phase shift network, which is probably why your Dennesen worked so well.


It still works, if I can stand to look at it. :-) However, my primary
residence sports a Sniper these days with Yaesu rotor.

A single vertical whip receives equally well from all directions. This
means
that reduction in multipath can be accomplished only by moving the

antenna
about the room. By contrast, a dipole can be rotated through 180
vertically,
and 180 degrees horizontally, while in the same location, provided one

can
find a way to support the floppy wires. Taping it to a dowell stick

would
work.



I hear you, but when using an A/B switch and watching the trace as you
switch antennas, any changes in multipath reception are easily detected.
Using such setup, I can only conclude that the ST-2, generally speaking,

is
not impeded by multipath reception and will deliver a stronger, cleaner
signal to a tuner than a R/S dipole and its cousins.


Cheers,

Margaret


I don't doubt the result. Your reply has forced me to additional thought:

1.Mere inches are significant to multipath.

2. The other thing which is signficant is this: the ST-2 connects to the
receiver by coax, which picks up negligible signal by itself. The twinlead
from a folded dipole is part of the antenna system itself. Therefore, it
picks up more signal, which can cancel with that received by the nominal
antenna. Back in the 60's, people would prewire their houses with twinlead
for a rooftop TV antenna, and the ghosting (visual multipath) was vicious.
Replacing it with coax eliminated the distribution system as a secondary
antenna.

I should append the following note to my original advice to "ric". After
constructing his custom 33.5" folded dipole, he should purchase a balun
transformer from Radio Shack or any other source. He should connect the
pigtails on the balun to the feed of the dipole, and he should run coaxial
cable to his receiver.


  #7   Report Post  
Margaret von B.
 
Posts: n/a
Default


"Robert Morein" wrote in message
...

"Margaret von B." wrote in message
news

"Robert Morein" wrote in message
...

"Margaret von B." wrote in message
...

"Robert Morein" wrote in message
...

"ric" wrote in message
...
Robert Morein wrote:

Are you familiar with the FM2G-C? It is being strongly

considered.

http://www.fanfare.com/fm-2g-c.html

This is an omnidirectional antenna, which means it will be very
susceptible
to multipath. The fact that it is cut for the educational band

gives
it
a
little more gain, but, as I said, gain is seldom the problem. The
problem is
phase cancellation caused by reception of a signal that is

reflected
by
two
or more different paths. This causes the signal to actually
cancel
100%
at
certain frequencies. More gain on nothing does not result in
something.
The
solution is a directional antenna, which attenuates all but one
of
the
reception paths, eliminating the phase cancellation.

Hmmm...I'm getting a slew of opinions on this, and few of them
reach
the same conclusion. Such as:

http://www.hawaiipublicradio.org/recep.htm

I've tried various dipole antennas, all with similar results. Best
results so far was an RCA powered indoor TV "rabbit ear" type

antenna.

I'm tempted to have an antenna cut specifically for 88.3 MHz, as

that
is
the only FM I listen to. Oh well...

You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be
1/2
that
length: 33.5. All you need is a piece of twinlead, which is just

junky
antenna lead-in wire. Cut it to 33.5 inches. At each end, twist the
conductors together. At the center, break one conductor. Connect the
loose
ends to your feed wire. It is not essential, but nice, if you can

have
t
the
connections soldered. Protect the wires from bending and breaking by
encasing the joints in some RTV (GE silicone goo).

I do not understand why the station engineer recommended the
Fanfare.

I do. It worked in his location.

This
antenna has 0 dB gain. 0 is a very small number. The only advantage

to
the
Fanfare is for external use, since it is self-supporting. An indoor
dipole,
which can be taped or tacked to any convenient surface, does not
need
mechanical rigidity.

A properly cut dipole has twice the signal strength: 3 dB.




There's more to antennas than theory, especially these "little ones".

As
I
stated before, I don't have any experience of this particular antenna

but
I
have plenty of experience of seemingly similar design, The Magnum

Dynalab
ST-2.

http://www.magnumdynalab.com/x_st2.htm

It has worked admirably well over the years in many urban locations
except
one. NYC RF hell rendered it pretty much useless. However, at the time

I
did
not have the Signal Sleuth that greatly complements the whip albeit at

a
considerable cost.

http://www.magnumdynalab.com/x_sleuth.htm

Based on my "nontechnical" opinion I can say that the whip alone
generally
outperforms the "grocerybagful" of dipoles I've accumulated over the
years
by a comfortable margin. With the Sleuth, it is the ultimate quick and
small
FM antenna solution. One of my favorite tuners has a scope that allows
the
monitoring of multipath signals and contrary to what one might think,

the
ST-2 is not all that easily bothered by it. That said, there are
locations,
such as NYC, where the cheap but nearly unobtainable Dennesen dual
whip
cannot be beat. I suspect that the Dennesen would be an easy DIY

project
for
those so inclined.

But no one should fool themselves into thinking that any of these
products
will succesfully compete with a competent outdoor antenna such as

those
made by APS.

Cheers,

Margaret

Margaret, without contradicting your experience, I think that the
difference
in sound has to do with the placement of the antenna.


That's probably most of it. As I said, "there's more than theory"...

Perhaps the
freestanding whip was placeable in a way that the dipole was not.
The real solution comes from an antenna arrangement with some
directionality. If the multipath signal(s) can be reduced below one
particular strongest signal, then phase cancellation cannot occur. Two
whips
separated by 1/2 wavelength can be directionally oriented by a
combining
phase shift network, which is probably why your Dennesen worked so
well.


It still works, if I can stand to look at it. :-) However, my primary
residence sports a Sniper these days with Yaesu rotor.

A single vertical whip receives equally well from all directions. This
means
that reduction in multipath can be accomplished only by moving the

antenna
about the room. By contrast, a dipole can be rotated through 180
vertically,
and 180 degrees horizontally, while in the same location, provided one

can
find a way to support the floppy wires. Taping it to a dowell stick

would
work.



I hear you, but when using an A/B switch and watching the trace as you
switch antennas, any changes in multipath reception are easily detected.
Using such setup, I can only conclude that the ST-2, generally speaking,

is
not impeded by multipath reception and will deliver a stronger, cleaner
signal to a tuner than a R/S dipole and its cousins.


Cheers,

Margaret


I don't doubt the result. Your reply has forced me to additional thought:

1.Mere inches are significant to multipath.

2. The other thing which is signficant is this: the ST-2 connects to the
receiver by coax, which picks up negligible signal by itself. The twinlead
from a folded dipole is part of the antenna system itself. Therefore, it
picks up more signal, which can cancel with that received by the nominal
antenna. Back in the 60's, people would prewire their houses with twinlead
for a rooftop TV antenna, and the ghosting (visual multipath) was vicious.
Replacing it with coax eliminated the distribution system as a secondary
antenna.

I should append the following note to my original advice to "ric". After
constructing his custom 33.5" folded dipole, he should purchase a balun
transformer from Radio Shack or any other source. He should connect the
pigtails on the balun to the feed of the dipole, and he should run coaxial
cable to his receiver.


That should do it. OTOH, the person who bought my old "nightmare reception"
loft in NYC simply ended up buying a Blaupunkt car stereo with a diversity
tuner and got better results than with any home units at a fraction of the
cost. Of course one still needs to optimize antenna location, but it is
pretty much set and forget. I was stunned how well it worked. In fact, I
should buy one of those Blaupunkts and compare it to my existind tuners for
the fun of it. I believe even the Audio Critic did an article on the
Blaupunkt tuners after they got a whiff of it...

Cheers,

Margaret







  #8   Report Post  
Goofball_star_dot_etal
 
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On Wed, 22 Jun 2005 20:56:44 -0400, "Robert Morein"
wrote:


The twinlead
from a folded dipole is part of the antenna system itself. Therefore, it
picks up more signal, which can cancel with that received by the nominal
antenna.


********! (7)
It is a balanced transmission line which is matched to the balanced
300ohm folded dipole. The fields associated with the twin conductors
of the feeder cancel in the far field. It cannot radiate/recieve
itself if it is properly balanced.

Back in the 60's, people would prewire their houses with twinlead
for a rooftop TV antenna, and the ghosting (visual multipath) was vicious.
Replacing it with coax eliminated the distribution system as a secondary
antenna.


"twinlead" has lower losses than coax, (for similar size/cost)
however the disadvantage is that the fields extend outside the bounds
of the cable, whereas with coax it is within. To get the best out of
balanced feed it should be spaced away from other materials. Coax can
be attached to walls, taped to metal poles, etc. It also needs a
decent balun to connect to a dipole.

  #9   Report Post  
Goofball_star_dot_etal
 
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On Wed, 22 Jun 2005 08:56:42 -0400, "Robert Morein"
wrote:

One is disappointed in f'ing wannabee Usenet scientists. . .


The wavelength of 88.3 mHz


milli Hertz?



is 66.88 inches.


********!
Try twice that. (300e6 /88.3e6 x100/2.54) inches.

Your dipole should be 1/2 that
length: 33.5. All you need is a piece of twinlead, which is just junky
antenna lead-in wire. Cut it to 33.5 inches. At each end, twist the
conductors together. At the center, break one conductor. Connect the loose
ends to your feed wire. It is not essential, but nice, if you can have t the
connections soldered. Protect the wires from bending and breaking by
encasing the joints in some RTV (GE silicone goo).


I do not understand why the station engineer recommended the Fanfare. This
antenna has 0 dB gain. 0 is a very small number. The only advantage to the
Fanfare is for external use, since it is self-supporting. An indoor dipole,
which can be taped or tacked to any convenient surface, does not need
mechanical rigidity.

A properly cut dipole has twice the signal strength: 3 dB.


********!
Try 0dB (the gain of an antenna is specified wrt a dipole!)







  #10   Report Post  
ric
 
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Robert Morein wrote:

You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2 that
length: 33.5.


Hmmm...the website you give above contradicts that. It says:

1/2 WL dipole length = 468/f = 468/88.3 = 5.3 feet = 63.6 inches.

Since none of the existing FM dipoles I have are 63.6 inches long (the
longest being just under 5 feet), should I assume that is why they are
so poor in the "college" (88-90 MHz) FM band?


  #11   Report Post  
Robert Morein
 
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"ric" wrote in message ...
Robert Morein wrote:

You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2

that
length: 33.5.


Hmmm...the website you give above contradicts that. It says:

1/2 WL dipole length = 468/f = 468/88.3 = 5.3 feet = 63.6 inches.

Since none of the existing FM dipoles I have are 63.6 inches long (the
longest being just under 5 feet), should I assume that is why they are
so poor in the "college" (88-90 MHz) FM band?


I'm sorry, Ric. I made a mistake.
The folded dipole is cut to 1/4 wavelength, which is why it works out to
33.5 inches for your frequency of interest.


  #12   Report Post  
Goofball_star_dot_etal
 
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On Sat, 25 Jun 2005 18:24:43 -0400, "Robert Morein"
wrote:


"ric" wrote in message ...
Robert Morein wrote:

You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2

that
length: 33.5.


Hmmm...the website you give above contradicts that. It says:

1/2 WL dipole length = 468/f = 468/88.3 = 5.3 feet = 63.6 inches.

Since none of the existing FM dipoles I have are 63.6 inches long (the
longest being just under 5 feet), should I assume that is why they are
so poor in the "college" (88-90 MHz) FM band?


I'm sorry, Ric. I made a mistake.
The folded dipole is cut to 1/4 wavelength, which is why it works out to
33.5 inches for your frequency of interest.

********! 1,2,3,4. . .mistakes.

  #14   Report Post  
Joseph Oberlander
 
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ric wrote:

Robert Morein wrote:


You can do it yourself. Take a look at
http://www.ycars.org/EFRA/Module%20C/AntDip.htm

The wavelength of 88.3 mHz is 66.88 inches. Your dipole should be 1/2 that
length: 33.5.



Hmmm...the website you give above contradicts that. It says:

1/2 WL dipole length = 468/f = 468/88.3 = 5.3 feet = 63.6 inches.

Since none of the existing FM dipoles I have are 63.6 inches long (the
longest being just under 5 feet), should I assume that is why they are
so poor in the "college" (88-90 MHz) FM band?


Ah. you *can* get 6 fters. They are custom parts, though, and not
sold at Radio Shack and simmilar places.

  #15   Report Post  
ric
 
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Joseph Oberlander wrote:

1/2 WL dipole length = 468/f = 468/88.3 = 5.3 feet = 63.6 inches.

Since none of the existing FM dipoles I have are 63.6 inches long (the
longest being just under 5 feet), should I assume that is why they are
so poor in the "college" (88-90 MHz) FM band?


Ah. you *can* get 6 fters. They are custom parts, though, and not
sold at Radio Shack and simmilar places.


Even the $25 "FM Select" dipole has only a 54" element. That's optimized
for 104 MHz. No thanks.

http://www.ccrane.com/fm-reflect-antenna.aspx


  #16   Report Post  
Joseph Oberlander
 
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ric wrote:

Joseph Oberlander wrote:


1/2 WL dipole length = 468/f = 468/88.3 = 5.3 feet = 63.6 inches.

Since none of the existing FM dipoles I have are 63.6 inches long (the
longest being just under 5 feet), should I assume that is why they are
so poor in the "college" (88-90 MHz) FM band?


Ah. you *can* get 6 fters. They are custom parts, though, and not
sold at Radio Shack and simmilar places.



Even the $25 "FM Select" dipole has only a 54" element. That's optimized
for 104 MHz. No thanks.

http://www.ccrane.com/fm-reflect-antenna.aspx


Try looking in CB supply stores and also marine equipment. These
ultra-long antennas are common on shortwave radios as well.

http://www.qsradio.com/QuickSticks.htm
96 inches should be long enough for any application.

  #17   Report Post  
Goofball_star_dot_etal
 
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On Tue, 28 Jun 2005 15:41:39 GMT, Joseph Oberlander
wrote:



ric wrote:

Joseph Oberlander wrote:


1/2 WL dipole length = 468/f = 468/88.3 = 5.3 feet = 63.6 inches.

Since none of the existing FM dipoles I have are 63.6 inches long (the
longest being just under 5 feet), should I assume that is why they are
so poor in the "college" (88-90 MHz) FM band?

Ah. you *can* get 6 fters. They are custom parts, though, and not
sold at Radio Shack and simmilar places.



Even the $25 "FM Select" dipole has only a 54" element. That's optimized
for 104 MHz. No thanks.

http://www.ccrane.com/fm-reflect-antenna.aspx


Try looking in CB supply stores and also marine equipment. These
ultra-long antennas are common on shortwave radios as well.

http://www.qsradio.com/QuickSticks.htm
96 inches should be long enough for any application.

Sigh. Size isn't everything.
Those are HF aerials with blobby things.
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