[amsat-bb] Re: International Space Station-Bounce on 1296 MHz

[Andreas Imse]

Hi Domenico,

 

your plan is really interesting, but I cannot support you with exact data at
present.

Maybe the wav file recorded by my SDR can give you an impression of the QSO:
https://docs.google.com/file/d/0B8ak4za2va9ZVld5ZXZaREE5bXc/edit?usp=sharing

 

I did not receive own echoes off the ISS, just the ones of PA3FXB, who was
using a 3 m dish as well and 375 W at feed. We used plain CW and I heard Jan
on my speaker with 2700 Hz Bandwidth.

As it was the very first shot, just to complete a QSO, no semi scientific
records were made, hi. There were too many other things to mention about.

 

But it is a good idea to record all data as current elevation, azimuth,
slant range, relative speed and doppler to a file. Since I do the complete
station control including CW transmission by a homebrew program,

it is just a small piece of work to do, to realize that. These data could
easily be synchronized with a wav file, like the one linked above, by using
the switching  between RX and TX.

 

Jan and I plan further tests, when ISS will appear again at more moderate
times ;-)

 

We are thinking about FSK441 tests too, but not at present.

 

 

vy 73,

Andreas

 

 

Andreas Imse

DJ5AR / EI8HH

Hinter der Kirche 31

55129 Mainz

Germany

 

+49 6136 959025

dj5ar at darc.de

www.dj5ar.de

 

 

 

 

Von: i8cvs [mailto:domenico.i8cvs at tin.it] 
Gesendet: Donnerstag, 30. Mai 2013 01:13
An: Andreas Imse
Betreff: Re: [amsat-bb] Re: International Space Station-Bounce on 1296 MHz
Wichtigkeit: Hoch

 

Hi Andreas, DJ5AR

 

Using the RADAR equation I would like to perform a link calculation of your
QSO with Jan PA3FXB through the International Space Station-Bounce on 1296
MHz

 

I already know that the gain of your 3 meter dish is 29 dB and your power at
the feed point is 200 W but I need the additional estimated following
informations:

 

1) The range and the elevation from the ISS and your QTH as soon you started
receiving your own ECHO'es  

     signals.

 

2) The maximum range and the elevation from the ISS and your QTH when your
received signals were the 

     strongest possible. 

 

3) Were you receiving in analogic CW using 500 Hz filter and headphone or
were you using digital WSJT software 

     such as FSK441 or others software (commonly used for rapidly moving
meteor scatter QSO's). ? 

 

When the ISS is at the AOS with elevation of 2 degrees the range is about
2000 km and when the elevation is about 35 degrees the range is about 700 km
so that I plan to calculate the budged link for both distances 2000 km and
700 km and see what the results are in Signal to Noise ratio using only a
analogic CW receiver and than calculate the advantages using a digital
system.

 

Thanks for your answere.
 

73" de 

 

i8CVS Domenico

----- Original Message ----- 

From: Andreas Imse <mailto:andreas at imse.de>  

To: domenico.i8cvs at tin.it 

Sent: Tuesday, May 28, 2013 9:23 AM

Subject: [amsat-bb] Re: International Space Station-Bounce on 1296 MHz

 

Hi Domenico,

 

I saw your posting and will give you a short reply.

 

We are both using 3 m dishes, 200 W here and 375 W on Jan´s side.

That was far enough for our tests. 

As our QTHs are quite close (only 367 km), it is possible that QSOs over a
larger distances might be possible with less power like in aircraft scatter.


If you are equipped for 1296 MHz and able to track the ISS with your
antenna, we should have a try.

Doppler compensation can be done completely on my side.

 

By the way: I have been visiting Naples and Stromboli 3 years ago and
remember passing Torre del Greco with the Circum Vesuviana.

 

vy 73,

Andreas

 

 

Andreas Imse

DJ5AR / EI8HH

Hinter der Kirche 31

55129 Mainz

Germany

 

+49 6136 959025

dj5ar at darc.de

www.dj5ar.de