[amsat-bb] Re: Po-63

[K7XQ]

I will checkout this interesting possibility too. The batteries maybe dead
but the 
solar panels may be supplying just enough energy to start turning on 
some of the electronics on board. Some local oscillator circuits can 
start generating RF with just afew volts of DC but will also have 
considerable frequency drift since the PLL's may not lock the oscillators 
on the correct frequency.

On noticed recently when I got my 2304 MHz EME system up and running, 
I was hearing quite afew signals drifting across the band just as you 
described here. This band is loaded with satellites active and declared 
dead as well. XM satellite radio operates right around our HAM band, I 
just found out, at around 2320 MHz, the EU EME segment of the band !!

Auke, was the satellite seeing sunlight on your program when you ran those
times ?

K7XQ Jeff
Atwater,CA.
Grid: CM97qi
EME CW and JT-65 modes

50 MHz: 2 X M2 7 ele 13 dBd  1 kW pending 2 X 3-500Z
144 MHz: 4 X M2 2MPX28 w/polarity rot 21.5 dBd 1.5 kw single GS35b
222 MHz: 1 X M2 5 W.L. no polarity rot 15 dBd 400 watts
432 MHz: 4 X M2 9 W.L. 23.3 dBd 1.5 kW single GS-35b
1296 MHz: 3 meter dish 27 dBd 350 watts single water cooled GS-15
2304 MHz: 3 meter dish 32 dBd 180 watts SS Spectrain Amplifier
10 GHz: 3 meter dish 45 dBd 18 watt TWTA  Still under construction ! 

K7XQ Webpage:  http://www.elite.net/~k7xq/k7xq.html
 

-----Original Message-----
From: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] On
Behalf Of Mike Rupprecht
Sent: Saturday, November 10, 2007 1:55 PM
To: 'Auke de Jong, VE6PWN'; 'AMSAT-BB'
Subject: [amsat-bb] Re: Po-63


Hi Auke,

I'm sure - that's not PEHUENSAT. 
There is only an alkaline battery on board and transmission stops end of
January.

73, Mike
DK3WN 





-----Ursprüngliche Nachricht-----
Von: amsat-bb-bounces at amsat.org [mailto:amsat-bb-bounces at amsat.org] Im
Auftrag von Auke de Jong, VE6PWN
Gesendet: Samstag, 10. November 2007 19:05
An: AMSAT-BB
Betreff: [amsat-bb] Po-63

I would like to draw attention to a unique occurance that I have noticed
today and last night... 
I was sitting on 144.200.0 usb with spectran running on the compy for no
good reason, when suddenly i noticed a carrier sweeping down through my
scope.  By itself, this would be nothing special, BUT I recognized a
pattern: the sweep rate was not linear, but resembled that of doppler-shift
from a passing LEO satellite!  it started out at one rate, then got faster
as it passed through my IF, and past zero-beat.  I retuned down, and
continued to observe it become slower, finally fading-out rather abruptly
while still sweeping down at a slower rate.  

I could not find any reason why any terrestrial signal might do this, so I
looked through my list of sats on Orbitron, to see if there was any hardware
that had passed recently.  I noticed that "PEHUENSAT-1[+]" had JUST LOS my
horizon on it's ascending orbit, and had been almost directly overhead a few
minutes before.  I made a mental note, and decided to check again on a
future pass to see if it happened again, just to rule-out other
possibilities.  

Sure enough, this morning on orbit # 4414, I was again, monitoring 144.200.0
usb and doing other tasks when I looked over at the PC and saw the same
pattern.  A check of Orbitron, showed that PO-63 just SO happens to be
almost LOS decending from overhead.  

This brings a question which begs to be answered: How can this signal seem
to be coming from this satellite?  As far I as I can tell by searching
google, the satellite is no longer functioning.  could it be a reflection of
a terrestrial signal, or could it be generated somehow by a malfunctioning
onboard transmitter?

I would like to hear from others about comparable observations or other
insight.  

Thanks,
Auke, VE6PWN
DO33
_______________________________________________
Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author. Not
an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb


____________
Virus checked by G DATA AntiVirusKit
Version: AVK 18.447 from 09.11.2007
Virus news: www.antiviruslab.com


_______________________________________________
Sent via AMSAT-BB at amsat.org. Opinions expressed are those of the author. Not
an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb