Fausto, the effect referred to by the professionals as ICM Ionospheric
Cross-Modulation.....is probably what you hear. The two stations are often
refered to as the "heater" and the "victim". The "heater" is the station
activating the ionosphere into a non-linear state. It will be between you
and the "victim" and it is probable that you would only receive the victim
by ionospheric means (it is out of ground wave range) The victim and heater
will probably lie in an arc of about 30 degrees from your location, with the
heater between you and the victim. The heater will probably be a station of
at least 500kW though the effect can be noticed on 100kW Loran stations one
needs sophisticated reception procesing to extract the Loran pulses from the
victim. The effect is selom heard in daylight because there is more
attenuation in the D-layer.
The higher frequencies of the modulation are most noticable giving it an
"etherial" effect
I do have some papers buried in my archive on the effect, and I discussed it
at length with Vaino OH2LX in the early days of 136kHz.
Alan G3NYK
----- Original Message -----
From: "Fausto Coletti" <[email protected]>
To: <[email protected]>
Sent: Tuesday, January 04, 2011 5:05 PM
Subject: Re: LF: Luxembourg effect
I could not send the audio file attachment to the reflector, i think for Kb
limit,
the signal is not strong and is audible also with 30 dB attenuator at the
antenna so,
is not a receiver overload. I have read some documentation and i think that
this "ghost signal" is Luxembourg effect.
Note that i receive it only after sunset. During daylight the signal
disappears.
Fausto IK4NMF
----- Original Message -----
From: John Rabson
To: [email protected]
Sent: Tuesday, January 04, 2011 10:34 AM
Subject: Re: LF: Luxembourg effect
Fausto,
I believe the Luxembourg effect is a form of cross-modulation occurring in
the ionosphere when there is a high power transmitting station somewhere on
the path between the receiving and transmitting stations, but the signal
from the interfering station is not strong enough to overload the receiver.
Could one of our propagation experts provide a more detailed explanation
please?
73
John F5VLF
On 3 Jan 2011, at 15:59CET, Fausto Coletti wrote:
Is this a Luxembourg effect ?
First 40 sec i listen at 137 KHz, after i tune at 153 KHz on the
original transmission.
RX is a Perseus SDR with a 200 KHz low pass filter at the input for
eliminate MF overload.
The word "trial" every tot second is because i have install a trial
version of VAC software.
Fausto IK4NMF
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