"Dave"

all antennas are dipoles, you just can't always see the other half.
and Luxembourg has nothing to do with it, your silly frequency
doubling notions should be packaged up in art's box and never see the
light of day.


** ROTFL !!

Dave should be writing scripts for Mickey Mouse cartoons.

Cos he has the IQ of Daffy Duck.



.... Phil

On Mar 21, 11:34*am, "Phil Allison" wrote:
"Dave"

all antennas are dipoles, you just can't always see the other half.
and Luxembourg *has nothing to do with it, your silly frequency
doubling notions should be packaged up in art's box and never see the
light of day.

** ROTFL *!!

Dave should be writing scripts for Mickey Mouse cartoons.

Cos he has the IQ of Daffy Duck.

... * Phil

just trying to put it on S.B.'s level of understanding.

"Dave" wrote
...
On Mar 20, 8:26 am, Szczepan Bia³ek wrote:
"Phil Allison"
...

"Richard Clark"

Now, as to your experience of receiving signals on the wrong
frequency, that is a classic situation of image rejection being poor
due to the lack of a tuned front-end (something that dissappeared with
the dinosaurs). If I were to guess on the basis of 40 year old
experience fixing these suckers, your off-frequency signals are
probably shifted by twice the IF frequency of your receiver. The
classical FM IF frequency of 10.7 MHz might apply, but time has
marched on and designers may select their own. This old standard
would argue that you shouldn't experience images except where they
would be out-of-band (the 88-107 band with this IF would force that).

** Hearing the same FM station at more than one spot is still possible
even with a 10.7 MHz IF frequency - if the signal is very strong. The
reason is harmonics of the incoming carrier generated in the RF stage
interacting with harmonics of the local oscillator in the mixer.

It sound like the "Luxembourg Effect". The signal was from the dipole
antenna.
Are now the FM stations which use the dipoles?

Eg:

A 100MHz FM carrier generates a harmonic at 200MHz in the receiver.

When the local oscillator is adjusted to 94.65 MHz, its second harmonic
is
189.3 MHz.

The difference frequency is then 10.7 MHz - so goes through to the FM
detector.

In this situation, the FM deviation is doubled so the recovered audio
will
be distorted on loud passages.

all antennas are dipoles, you just can't always see the other half.

If I can't see the other half it is the monopole.
So I repeat my question: Are now the FM stations which use the dipoles?


and Luxembourg has nothing to do with it, your silly frequency
doubling notions should be packaged up in art's box and never see the
light of day.

The dipoles have the directional pattern like this:
http://www-antenna.ee.titech.ac.jp/~...ole/index.html

It looks like the interference of the many sources (dipoles have the two).

The two sources not in phase double the frequencies.
S*

On Mar 21, 11:42*am, Szczepan Bia³ek wrote:
"Dave" ...
On Mar 20, 8:26 am, Szczepan Bia ek wrote:



"Phil Allison"
...

"Richard Clark"

Now, as to your experience of receiving signals on the wrong
frequency, that is a classic situation of image rejection being poor
due to the lack of a tuned front-end (something that dissappeared with
the dinosaurs). If I were to guess on the basis of 40 year old
experience fixing these suckers, your off-frequency signals are
probably shifted by twice the IF frequency of your receiver. The
classical FM IF frequency of 10.7 MHz might apply, but time has
marched on and designers may select their own. This old standard
would argue that you shouldn't experience images except where they
would be out-of-band (the 88-107 band with this IF would force that)..

** Hearing the same FM station at more than one spot is still possible
even with a 10.7 MHz IF frequency - if the signal is very strong. The
reason is harmonics of the incoming carrier generated in the RF stage
interacting with harmonics of the local oscillator in the mixer.

It sound like the "Luxembourg Effect". The signal was from the dipole
antenna.
Are now the FM stations which use the dipoles?

Eg:

A 100MHz FM carrier generates a harmonic at 200MHz in the receiver.

When the local oscillator is adjusted to 94.65 MHz, its second harmonic
is
189.3 MHz.

The difference frequency is then 10.7 MHz - so goes through to the FM
detector.

In this situation, the FM deviation is doubled so the recovered audio
will
be distorted on loud passages.
all antennas are dipoles, you just can't always see the other half.

If I can't see the other half it is the monopole.
So I repeat my question: Are now the FM stations which use the dipoles?

and Luxembourg *has nothing to do with it, your silly frequency

doubling notions should be packaged up in art's box and never see the
light of day.

The dipoles have the directional pattern like this:http://www-antenna.ee.titech.ac.jp/~...ole/index.html

It looks like the interference of the many sources (dipoles have the two)..

The two sources not in phase double the frequencies.
S*

so why when i switch my transmitter from a 'monopole' where YOU can't
see the other half to a dipole does the frequency stay the same?

"Dave" wrote
...
On Mar 21, 11:42 am, Szczepan Bia³ek wrote:
"Dave"
...
On Mar 20, 8:26 am, Szczepan Bia ek wrote:



"Phil Allison"
...

"Richard Clark"

Now, as to your experience of receiving signals on the wrong
frequency, that is a classic situation of image rejection being poor
due to the lack of a tuned front-end (something that dissappeared
with
the dinosaurs). If I were to guess on the basis of 40 year old
experience fixing these suckers, your off-frequency signals are
probably shifted by twice the IF frequency of your receiver. The
classical FM IF frequency of 10.7 MHz might apply, but time has
marched on and designers may select their own. This old standard
would argue that you shouldn't experience images except where they
would be out-of-band (the 88-107 band with this IF would force that).

** Hearing the same FM station at more than one spot is still
possible
even with a 10.7 MHz IF frequency - if the signal is very strong. The
reason is harmonics of the incoming carrier generated in the RF stage
interacting with harmonics of the local oscillator in the mixer.

It sound like the "Luxembourg Effect". The signal was from the dipole
antenna.
Are now the FM stations which use the dipoles?

Eg:

A 100MHz FM carrier generates a harmonic at 200MHz in the receiver.

When the local oscillator is adjusted to 94.65 MHz, its second
harmonic
is
189.3 MHz.

The difference frequency is then 10.7 MHz - so goes through to the FM
detector.

In this situation, the FM deviation is doubled so the recovered audio
will
be distorted on loud passages.
all antennas are dipoles, you just can't always see the other half.

If I can't see the other half it is the monopole.
So I repeat my question: Are now the FM stations which use the dipoles?

and Luxembourg has nothing to do with it, your silly frequency

doubling notions should be packaged up in art's box and never see the
light of day.

The dipoles have the directional pattern like
this:http://www-antenna.ee.titech.ac.jp/~...ole/index.html

It looks like the interference of the many sources (dipoles have the two).

The two sources not in phase double the frequencies.
S*

so why when i switch my transmitter from a 'monopole' where YOU can't
see the other half to a dipole does the frequency stay the same?

Your transmitter has the same but in the receiver antenna is possibility
that appear the doubled frequency.
Luxembourg effect was observed in 1930. Now radio people manage with
eliminating it.
S*

On Sat, 20 Mar 2010 09:26:04 +0100, Szczepan Bia?ek
wrote:

It sound like the "Luxemburg Effect". The signal was from the dipole
antenna.

The Luxemburg effect is usually contributed to the suspected Radio
Luxemburg intermodulation products caused by the _ionosphere_
nonlinearities.

Similar intermodulation effects can be obtained by the nonlinearities
caused by rusty bolts in a transmitter tower.

On Mar 21, 12:11*pm, Szczepan Bia³ek wrote:
*"Dave" ...
On Mar 21, 11:42 am, Szczepan Bia ek wrote:



"Dave"
...
On Mar 20, 8:26 am, Szczepan Bia ek wrote:

"Phil Allison"
...

"Richard Clark"

Now, as to your experience of receiving signals on the wrong
frequency, that is a classic situation of image rejection being poor
due to the lack of a tuned front-end (something that dissappeared
with
the dinosaurs). If I were to guess on the basis of 40 year old
experience fixing these suckers, your off-frequency signals are
probably shifted by twice the IF frequency of your receiver. The
classical FM IF frequency of 10.7 MHz might apply, but time has
marched on and designers may select their own. This old standard
would argue that you shouldn't experience images except where they
would be out-of-band (the 88-107 band with this IF would force that).

** Hearing the same FM station at more than one spot is still
possible
even with a 10.7 MHz IF frequency - if the signal is very strong. The
reason is harmonics of the incoming carrier generated in the RF stage
interacting with harmonics of the local oscillator in the mixer.

It sound like the "Luxembourg Effect". The signal was from the dipole
antenna.
Are now the FM stations which use the dipoles?

Eg:

A 100MHz FM carrier generates a harmonic at 200MHz in the receiver..

When the local oscillator is adjusted to 94.65 MHz, its second
harmonic
is
189.3 MHz.

The difference frequency is then 10.7 MHz - so goes through to the FM
detector.

In this situation, the FM deviation is doubled so the recovered audio
will
be distorted on loud passages.
all antennas are dipoles, you just can't always see the other half.

If I can't see the other half it is the monopole.
So I repeat my question: Are now the FM stations which use the dipoles?

and Luxembourg has nothing to do with it, your silly frequency

doubling notions should be packaged up in art's box and never see the
light of day.

The dipoles have the directional pattern like
this:http://www-antenna.ee.titech.ac.jp/~...le/index..html

It looks like the interference of the many sources (dipoles have the two).

The two sources not in phase double the frequencies.
S*
so why when i switch my transmitter from a 'monopole' where YOU can't

see the other half to a dipole does the frequency stay the same?

Your transmitter has the same but in the receiver antenna is possibility
that appear the doubled frequency.
Luxembourg effect was observed in 1930. Now radio people manage with
eliminating it.
S*

nope, the receiver still hears the proper transmitted frequency.

Szczepan Bia³ek wrote:

"Dave" wrote
...
On Mar 20, 8:26 am, Szczepan Bia³ek wrote:
"Phil Allison"
...

"Richard Clark"

Now, as to your experience of receiving signals on the wrong
frequency, that is a classic situation of image rejection being poor
due to the lack of a tuned front-end (something that dissappeared with
the dinosaurs). If I were to guess on the basis of 40 year old
experience fixing these suckers, your off-frequency signals are
probably shifted by twice the IF frequency of your receiver. The
classical FM IF frequency of 10.7 MHz might apply, but time has
marched on and designers may select their own. This old standard
would argue that you shouldn't experience images except where they
would be out-of-band (the 88-107 band with this IF would force that).

** Hearing the same FM station at more than one spot is still possible
even with a 10.7 MHz IF frequency - if the signal is very strong. The
reason is harmonics of the incoming carrier generated in the RF stage
interacting with harmonics of the local oscillator in the mixer.

It sound like the "Luxembourg Effect". The signal was from the dipole
antenna.
Are now the FM stations which use the dipoles?

Eg:

A 100MHz FM carrier generates a harmonic at 200MHz in the receiver.

When the local oscillator is adjusted to 94.65 MHz, its second
harmonic is
189.3 MHz.

The difference frequency is then 10.7 MHz - so goes through to the FM
detector.

In this situation, the FM deviation is doubled so the recovered
audio will
be distorted on loud passages.

all antennas are dipoles, you just can't always see the other half.

If I can't see the other half it is the monopole.
So I repeat my question: Are now the FM stations which use the dipoles?

You significant lack of understanding of dipoles is causing you to ask
silly questions that are meaningless.




and Luxembourg has nothing to do with it, your silly frequency
doubling notions should be packaged up in art's box and never see the
light of day.

The dipoles have the directional pattern like this:
http://www-antenna.ee.titech.ac.jp/~...ole/index.html

This shows effects over a 48:1 frequency range. The FM band represents a
1.23:1 range. The image has no bearing on the topic at hand.


It looks like the interference of the many sources (dipoles have the two).

The two sources not in phase double the frequencies.

This is completely wrong. In a _linear_ systems adding two signals
cannot create new frequencies, including doubling. In the frequency
domain this is clear. If you look in the time domain and look at zero
crossings you may be confused. Do the math for the addition of two sine
waves of different phase. Stop relying on internet images you don't
understand and may not have any relevance to the discussion.

You can do the math in the time domain, or frequency domain. Either
should tell you there is no doubling of frequencies.

In order to generate new frequencies you need to have a non-linear
effect. Addition is NOT a non-linear operation.


S*

Szczepan Bia³ek wrote:

"Dave" wrote
...
On Mar 21, 11:42 am, Szczepan Bia³ek wrote:
"Dave"
...

On Mar 20, 8:26 am, Szczepan Bia ek wrote:



"Phil Allison"
...

"Richard Clark"

Now, as to your experience of receiving signals on the wrong
frequency, that is a classic situation of image rejection being poor
due to the lack of a tuned front-end (something that dissappeared
with
the dinosaurs). If I were to guess on the basis of 40 year old
experience fixing these suckers, your off-frequency signals are
probably shifted by twice the IF frequency of your receiver. The
classical FM IF frequency of 10.7 MHz might apply, but time has
marched on and designers may select their own. This old standard
would argue that you shouldn't experience images except where they
would be out-of-band (the 88-107 band with this IF would force
that).

** Hearing the same FM station at more than one spot is still
possible
even with a 10.7 MHz IF frequency - if the signal is very strong. The
reason is harmonics of the incoming carrier generated in the RF stage
interacting with harmonics of the local oscillator in the mixer.

It sound like the "Luxembourg Effect". The signal was from the dipole
antenna.
Are now the FM stations which use the dipoles?

Eg:

A 100MHz FM carrier generates a harmonic at 200MHz in the receiver.

When the local oscillator is adjusted to 94.65 MHz, its second
harmonic
is
189.3 MHz.

The difference frequency is then 10.7 MHz - so goes through to
the FM
detector.

In this situation, the FM deviation is doubled so the recovered
audio
will
be distorted on loud passages.
all antennas are dipoles, you just can't always see the other half.

If I can't see the other half it is the monopole.
So I repeat my question: Are now the FM stations which use the dipoles?

and Luxembourg has nothing to do with it, your silly frequency

doubling notions should be packaged up in art's box and never see the
light of day.

The dipoles have the directional pattern like
this:http://www-antenna.ee.titech.ac.jp/~...ole/index.html


It looks like the interference of the many sources (dipoles have the
two).

The two sources not in phase double the frequencies.
S*

so why when i switch my transmitter from a 'monopole' where YOU can't
see the other half to a dipole does the frequency stay the same?

Your transmitter has the same but in the receiver antenna is possibility
that appear the doubled frequency.


Luxembourg effect was observed in 1930. Now radio people manage with
eliminating it.

I doubt that ionization in the atmosphere has anything to do with what
is being observed.

However, overloading or cross modulation in the receiver is much more
likely.

S*

Michael A. Terrell wrote:
Joerg wrote:
amdx wrote:
"Joerg" wrote in message
...
amdx wrote:
"Richard Clark" wrote in message
...
On Fri, 19 Mar 2010 15:22:42 -0500, "amdx" wrote:

So I installed the antenna on the outside of the boat and the radio
inside,
now one station I listen to is weak, but if I unplug the antenna and
let the
center pin touch ground of the connector on the radio it comes in
great.
Just curious why it is working this way.
Hi Mike,

You moved the antenna.

Most loss of signal as you describe comes from not being a weak
signal, but the mixture of signals that combine negatively at some
spot due to multiple reflections. When you replaced the line cord as
antenna for this better implementation, you also found that "sour (not
sweet) spot." This can occur for any frequency with the equal
likelihood of reflections combining negatively. Move your antenna a
quarter wave and see what happens.

Your description of your having an aluminum boat almost guarantees a
multitude of RF-bright reflections. At short wavelengths, this also
guarantees many, many regions that will exhibit destructive (as well
as constructive) combinations of those reflections.

Put your antenna as far away from the superstructure or hull as
possible. This will reduce the reflection path differences.

BTW, the mod did cure the computer hash.
Mike
FM has what is called a "full quieting" effect. It would suggest that
your first signal levels were just barely above the level of full
quiet (and perhaps not even that good).

73's
Richard Clark, KB7QHC
Richard, after I read your letter I did a little better checking and
found
my signal is not weak it is to strong, I'm getting interference from
other frequencies.
Also I get stations on the wrong frequency.
I went out and collapsed the antenna to minimum about 1/3 of what it
was and
my problem station is perfect and the other station I listen to is still
good. The local
NPR station isn't good though. But I can download the podcast of Science
Friday :-)
Thanks, Mike
The usual, lousy FM tuner. They don't make'em like they used to. It's the
same with television sets, one large signal and they fall off the rocker.

If you have a radio with a signal strength meter you could notch out a
strong station. But that only works it it's just one and far away from the
NPR frequency. The only other options are to get a better radio, a
directional antenna, or just live with it and use the podcast.

--
Regards, Joerg
This morning I got on the boat and the signal that was improved to good by
shortening the antenna is now bad. 94.5 has interference from 101.1.
Oh well!
You really need a better quality radio and with radios and a lot of
other stuff older = better :-)

I mean, considering what the boat must have cost ...


Or a tuned trap to reduce the signal from that one station.


Well, that's what I suggested above, notch = trap :-)

But it's tough and can be impossible if there are useful weaker stations
near the one you want to muffle. In Europe they had a pager service
right at the lower end of the FM band. Whichever committee signed off on
that one should be dunked into a moat for gross incompetence, until they
either learn or quit their career. Anyhow, the inevitable happened, and
despite being a school kid I predicted that: A barrage of complaints by
FM listeners. In Germany they pay a radio tax so that makes them sort of
constituents with rights. Long story short the governement had to
furnish rather expensive notch filters to anyone who complained.

--
Regards, Joerg

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