[amsat-bb] Re: AMSAT Board of Directors Candidates

[Bill Ress]

Hi Rocky,

The ARISSat-1 uses a linear transponder that is significantly more 
efficient.

The COMM RX, CMD RX and the half watt output linear COMM TX only draws 
420 mA at 8 VDC. The entire design can also be configured to run 
directly from 3.6 Vdc, which is conveniently the voltage of a Lithium 
Ion cell. In the absence of the battery cell (if troubles arise with the 
battery), it could also run directly from a pair of series connected 
solar cells (but not at the 0.5 watt output level), which typically run 
about 4.6 V. Additionally, the design can also fit into the CubeSat 
physical configuration.

So William's design isn't there yet - at least the last I heard.

So you ask, why don't we use it in FOX?

Well 420 mA is still too to close to the current output capability for 
the typical CubeSat solar cell setup. Remember, you also need current to 
run the IHU, the MPPT etc. But we're always working on improving the 
efficient in the linear mode - so who knows.

The AMSAT-UK FUNCube folks will be designing a linear U/V transponder 
for their CubeSat, so we'll be watching their results closely.

Regards...Bill - N6GHz
ARISSat Team Member

Rocky Jones wrote:
> 
> 
>> Just have a look at PE1RAH William Leijenaar web page http://www.qsl.net/pe1rah/
>>
>> and look at his nano sat transponder satellite
>>
>> http://www.qsl.net/pe1rah/mysat2.htm
>>
>>
>>
>> Luc Leblanc VE2DWE
>> Skype VE2DWE
>> www.qsl.net/ve2dwe
>> DSTAR urcall VE2DWE
>> WAC BASIC CW PHONE SATELLITE
>>
>>  
> 
> It is a clever device.  I've never been clear as to why AMSAT NA is not using it.  Works great on the Indian satellite..
> 
> Robert G. Oler  WB5MZO Life member AMSAT ARRL
>  		 	   		  
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