Re: [amsat-bb] Digital Radio

["Johann Lochner" <lochner@xxxxxxxxxxxxx>]

Hi Matt,

 > My other question is could anybody supply me with RAM that has
 > 1meg or more of space per unit. The only ones that I have seen are
 > like 256K etc... I couldnt see a Satellite like SunSat using 250 of
 > these to make up its 60 or so megabytes of ram. 

Sunsat's ramtray consists of 8 piggy-back boards, each one containing 
16 x 512 kB chips.  I think they are made by Samsung (HM628512).  See 
how the boards and ramtray look by following these links:

<http://esl.ee.sun.ac.za/~lochner/aflaai/ram.jpg>
<http://esl.ee.sun.ac.za/~lochner/aflaai/ramtray.jpg>

Low density chips are less vulnerable to single event upsets, caused 
by high radiation levels in space.

Kind regards,
Johann, ZR1CBC

+------------------------------------------------+
   JG Lochner  ESL, Universiteit van Stellenbosch
   e-pos:      lochner@ing.sun.ac.za
   webtuiste:  http://esl.ee.sun.ac.za/~lochner
+------------------------------------------------+

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