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CX2SA > SATDIG 04.05.12 21:13l 236 Lines 6365 Bytes #999 (0) @ WW
BID : AMSATBB7142
Read: GUEST
Subj: AMSAT-BB-digest V7 142
Path: IZ3LSV<IK2XDE<DB0RES<DK0WUE<7M3TJZ<XE1FH<HI5MLE<CX2SA
Sent: 120504/1909Z @:CX2SA.SAL.URY.SA #:59915 [Salto] FBB7.00e $:AMSATBB7142
From: CX2SA@CX2SA.SAL.URY.SA
To : SATDIG@WW
Today's Topics:
1. VO52 (py5lf_)
2. Re: VO-52 (K5OE)
3. PBS Newshour Report On SpaceX (B J)
4. How to measure the performance of my satellite station ? (PA3GUO)
5. VO-52 not heard (i8cvs)
----------------------------------------------------------------------
Message: 1
Date: Thu, 3 May 2012 20:47:35 -0300
From: "py5lf_" <py5lf@xxxxxxxxxxxxx.xxx.xx>
To: <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] VO52
Message-ID: <000801cd2987$1fb60a00$5f221e00$@xxx.xx>
Content-Type: text/plain; charset="us-ascii"
Hi
VO52 not heard last two passes over SA . I hope there is no problem with the
sat.
73
PY5LF
Luciano Fabricio
www.qrz.com/db/py5lf
Curitiba-PR-Brazil GG54jm
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Message: 2
Date: Thu, 3 May 2012 20:04:03 -0400 (EDT)
From: K5OE <k5oe@xxx.xxx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] Re: VO-52
Message-ID: <8CEF7A08CAF7CF1-2518-2C377@xxxxxxxxxxxx.xxxxxx.xxx.xxx>
Content-Type: text/plain; charset="us-ascii"
Confirmed. Nothing heard at 2357.
73,
Jerry, K5OE
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Message: 3
Date: Fri, 4 May 2012 01:39:25 +0000
From: B J <va6bmj@xxxxx.xxx>
To: amsat-bb <amsat-bb@xxxxx.xxx>
Subject: [amsat-bb] PBS Newshour Report On SpaceX
Message-ID:
<CAP7QzkPpbr6aSddNRN9Tv_StaioFAzULNYnA3+XBYqRZsw==1A@xxxx.xxxxx.xxx>
Content-Type: text/plain; charset=ISO-8859-1
http://www.pbs.org/newshour/bb/science/jan-june12/spacex_05-03.html
73s
Bernhard VA6BMJ @ DO33FL
------------------------------
Message: 4
Date: Fri, 4 May 2012 10:29:00 +0200
From: PA3GUO <pa3guo@xxxxxxx.xx>
To: amsat-bb@xxxxx.xxx
Subject: [amsat-bb] How to measure the performance of my satellite
station ?
Message-ID: <20120504102900.31XLA.62733.root@xxxxxxxx>
Content-Type: text/plain; charset=utf-8
Since I had been in-active for quite a number of weeks, of course I first
wanted
to check if my (70cm) satellite station was still functional.
The first step I always take is listening to the stable beacon of HO-68, CW
@xxx.xxxxxx.
My goal is to have the antenna tracked automatically, and frequency PC
controlled by HRD.
When the result is that I hear the beacon, no doppler shift, I know this
first step is taken
(means hardware and software incl kepler sets seem to work). Now what next ?
Signal strength of that CW beacon is one way to measure my station, another
way
is looking at RAX-2, which transmits at 437.345 MHz (9k6 FM packets, KISS
mode).
RAX sends these days each 10 seconds a short burst of data. Using the free
decoding SW from the RAX team you can:
a) analyze the satellite data yourself
b) help the scientific experiments of the university by forwarding the
telemetry
c) test your own station !
http://rax.engin.umich.edu/?page_id=301
An example is this mornings pass, which had a max elevation of 46 degrees.
With
my 16 elements DK7ZB (http://pa3guo.com/ant_jun_2011.jpg) my station could
hear the satellite starting at 2 degrees elevation, and decode at around 8
degrees.
See the table below (decode timestamps from the decoding software)
4 May 2012 07:51:38 GMT (6.2 degrees elevation)
4 May 2012 07:51:49 GMT
4 May 2012 07:52:01 GMT
4 May 2012 07:52:09 GMT
4 May 2012 07:52:19 GMT
4 May 2012 07:52:29 GMT
4 May 2012 07:52:39 GMT
4 May 2012 07:52:50 GMT
4 May 2012 07:53:02 GMT
4 May 2012 07:53:10 GMT
4 May 2012 07:53:20 GMT
4 May 2012 07:53:30 GMT
4 May 2012 07:53:41 GMT
4 May 2012 07:53:51 GMT
4 May 2012 07:54:01 GMT
4 May 2012 07:54:11 GMT
4 May 2012 07:54:21 GMT
4 May 2012 07:54:32 GMT
4 May 2012 07:54:42 GMT
4 May 2012 07:54:52 GMT
4 May 2012 07:55:02 GMT
4 May 2012 07:55:12 GMT
4 May 2012 07:55:22 GMT
4 May 2012 07:55:33 GMT
4 May 2012 07:55:43 GMT
4 May 2012 07:55:53 GMT
4 May 2012 07:56:03 GMT
4 May 2012 07:56:13 GMT
4 May 2012 07:56:24 GMT
4 May 2012 07:56:34 GMT
4 May 2012 07:56:44 GMT
4 May 2012 07:56:54 GMT
4 May 2012 07:57:05 GMT
4 May 2012 07:57:15 GMT
4 May 2012 07:57:25 GMT
4 May 2012 07:57:35 GMT
4 May 2012 07:57:45 GMT
4 May 2012 07:57:55 GMT
4 May 2012 07:58:06 GMT
4 May 2012 07:58:16 GMT
4 May 2012 07:58:26 GMT
4 May 2012 07:58:36 GMT
4 May 2012 07:58:46 GMT (11 degrees)
...
4 May 2012 07:59:48 GMT (5 degrees)
So at the end my station stopped decoding at 11 degrees elevation, it picked
up a final beacon at 5 degrees.
We could define a kind of 'Ground Station Effectiveness' as number of
packets decoded (not heared!) between
a certain elevation threshold (eg 10 degrees). When no packet would be
missed my station would rate now
for 100% (at 10 degrees).
Or more scientifically: the GS effectiveness of PA3GUO's station is 100%
(@xx degrees elevation)
All kinds of items can bring this number down from 100% to lets say 80%:
- hard mechanical stop of the rotor, forcing a full 360 degrees turn during
a pass
- interference of other signals/satellite during a pass (at the same
frequency)
- tumbling of the satellite (antenne pointing to wrong direction)
- polarization changes (rotation of the satellite)
Well, the above shows that my 1x16 elements (horizontal pol) antenna works
fine to support missions like RAX.
No need for circular antenna (admitted: other satellite give different
results for circular (both better and worse)
Just sharing some thoughts, looking forward to your feedback / reflections !
Henk, PA3GUO
------------------------------
Message: 5
Date: Fri, 4 May 2012 20:16:34 +0200
From: "i8cvs" <domenico.i8cvs@xxx.xx>
To: "AMSAT-BB" <amsat-bb@xxxxx.xxx>, "Mani VU2WMY" <wmy@xxxx.xxx.xx>
Subject: [amsat-bb] VO-52 not heard
Message-ID: <000101cd2a22$4984b160$0401a8c0@xxxxxx>
Content-Type: text/plain; charset="iso-8859-1"
Hi Mani, VU2WMY and All on the list
Beacon and transponder of VO-52 were not heard over Europe to day
4 May 2012 during the ascending orbit 37853 at 17:44 UTC and it was
in full Sun light.
Yesterday 3 May VO-52 it was not heard over South America by PY5LF
and over USA by K5OE as well not heard over Europe by IW6OVD
Please let us know the actual situation.
TNX
73" de
i8CVS Domenico
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End of AMSAT-BB Digest, Vol 7, Issue 142
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