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 _________________________________________________________________ Hotmail is redefining busy with tools for the New Busy. Get more from your inbox. http://www.windowslive.com/campaign/thenewbusy?ocid=PID28326::T:WLMTAGL:ON:W... _______________________________________________ Sent via AMSAT-BB@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