Re: [amsat-bb] SUISAT forensics...

[G0MRF@xxxxxxx]

In a message dated 08/02/2006 13:59:04 GMT Standard Time, aa2tx@comcast.net  
writes:

Hi Ed,

Assuming sky noise temp of 1200K, I get
about 2  milliwatts of EIRP.

No doubt, something is wrong. If this was  working
correctly, you could hear it on an HT with a  ducky.

73,
Tony AA2TX


 
Hi Tony / Group.
 
The 2mW is consistant with my rough estimate from the 4th of  :
 
"spectran is used to detect EME signals that are below normal hearing  
threshold so in real terms this was very very weak, the sort of signal I would  
expect from a milliwatt or two."
 
Given the couple of snippets of telemetry we now have, it should be  possible 
to 'fault find' suitsat.   If the transceiver has failed -  perhaps from 
working in a vacuum, then its likely that a transistor has failed  and we are 
seeing the drive feeding through to the antenna. In that scanario  the current 
consumed by the Kenwood may have dropped to very low levels in  which case the 
battery should last a long time.
 
If the antenna or feedline has failed, then the TX may be running 500mW  in 
which case the battery will run down as predicted. - Unless high SWR  
protection also reduces the current consumption. - Anyone checking this  on the ground?
 
So, when will it stop transmitting? I wonder what capacity and type of  
battery suitsat has?  If it's Lithium Ion, then we can expect it to stay  quite 
close to full voltage, say greater than 24V and when its nearly  discharged the 
voltage will drop very quickly as did XO-53.
 
Good fun this.......
 
73
 
David  G0MRF
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