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Re: Mir bounce





Dear Jean-Louis:

Thank you very much for the detailed information.  There are a few
people here
in the USA which are also thinking about organization a
Earth-Mir-Earth weekend.


Surface of Mir:
It is difficult to calculate the amount of surface area on Mir from
moment to moment.
As the station rotates, relative to the observer, the solar panels
will also 
appear to move which can add to decrease the reflectivity of the
surface.
It will be a challenge, however it is possible with CW and SSB and
lots of ERP.


Minimal station:

Antenna 10 element  (typical gain in dBd units 9.3)
Coax loss assumed (RG-213, 75 feet, 2.0 db loss, 9.3-2.0 = 7.3 dBD)
RF Output at amp 100 watts
aprox ERP 600-700 watts
(note, on the occasions I heard one way echos from Mir, 
he sending station was using over 1000 ERP)

So if you have a true eme or just a big-gun, try it.
you may be the first to have a full two-way EME from Mir.


good luck
Miles WF1F MAREX



Jean-Louis.RAULT@tcc.thomson-csf.com wrote:
> 
> > > All of the Amateur Radio equipment on Mir is currently disconnected,
> > > however, have you tried to bounce your signal off of Mir?
> > > It called Earth-Mir-Earth?
> 
> Last summer, I organized a Mir bounce experiment.
> The team was composed of about 10 skilled french hams and we performed many
> skeds.
> We were using AO-10 class equipment working on 145 MHz, that is 50 to 80 W
> RF output to 10 or 12 el yagi beams.
> Preliminary link budgets were showing that a little positive S/N ratio could
> be obtained (with narrow band CW) if the equivalent surface or MIR was 100
> square meters or more on the 2 meters band.
> My own reception chain was including a 11 el circularly polarized yagi beam,
> followed by a SSB Electronic AsGa preamplifier and an ICOM IC-821H
> transceiver. That equipment allows me to clearly hear some Moon bounce
> stations.
> I used FFT tools like Spectrogram and CoolEdit 2000 as an help to detect
> tiny sigs in background noise.
> I must admit that we NEVER get any positive results (yes, we took the double
> Doppler effect into account).
> This pessimistic test report is just to inform any future MIR bounce
> candidate about the minimum rig performance he has to deal with.
> 
> We plan to start a new campain in the next few months, with more RF power
> and larger aerials.
> We hope to be ready before MIR lands  ...
> 
> Cheers
> 
> Jean-Louis F6AGR
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