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Re: (meteorobs) Question on radio meteors - Sporadic E ?



Michael Boschat <andromed@atm.daldot ca> said :
> I monitor 83.25 MHz but from the 4th have had awful reception and no
>meteors heard. 
snip
>if there is a simple way to know
>if any Sproadic-E is present?
----

( Caveat : Here in Europe ,,, )

The simplest way is by ear!
Sporadic-E is a localised area of enhanced 'reflectivity'.
Thus it favours stations in one direction but not another.
The localising effect is more pronounced the higher the frequency.
Thus, for example, here in the UK we may hear stations in NW Italy
on 144MHz but from a large area in SE France, Switzerland, and Northern
Italy on 50MHz, during an event.
It is very sporadic ( would you believe ! :-)  ) in that a station may
be 5&9++ one moment and gone altogether a few seconds later. Other
times it may persist for minutes or hours. Longer at low frequencies
than at the higher end. Sporadic in direction also. An event giving
propagation to Sardinia may fade out to be replaced by one to Spain.
It is mainly a daylight phenomenon, again particularily at the higher
freq.
The progression of a Sporadic-E enhancement can be monitored on a
panoramic receiver, watching the spectrum fill up from 25MHz on up
through 50MHz then into 100MHz etc. as the event intensifies.
However that really only works at low solar cycle.
At this time in the solar cycle the picture is confused by regular
E and F-layer propagation in the high HF and low VHF.

I am not sure about F-layer, but could regular E-layer extend up to
80MHz at this time ? Not sure. Could this be the cause perhaps ?
Regular E does not get up to 144MHz even at solar max.
Tropo-ducting (not related to solar) does.
So, you need your ear on to sort it all out! At least here in Europe
we have the advantage that to hear a Polish or an Italian voice we
instantly know that there is odd propagation !
Malcolm runs for cover as a group of Quebecois throw things at him :-)

So, monitor the 50 or 144 MHz amateur bands and if loadsa folk start
yelling you know sumat is about !
The sporadic-E itself does not make a noise(interference).
I think you need to be more specific about the type of awfulness !
What exactly are you hearing that is bloting out your meteor reflections?

Malcolm.


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