[amsat-bb] Re: [amsat-edu] Link Budget for Cornell University's student built satellite Violet

Nick quadpugh at bellsouth.net
Thu Apr 16 04:35:48 PDT 2009


Hi Danny
You did a good job on the link budget. Jan King is the author and he will
comment if you send him a copy. Here are my comments.


	1. Patch antennas are hard to put on a cubesat because of their
size.
	2. If you fly dipoles they have very deep lobes of the end of the
ends and will cause deep
         fades when the antenna alimented off the ends.
	3. The ground antenna when at 5 degrees  elevation look into the
warm earth i.e. 290 deg K

For a reality check go copy AO 51. Copy the telemetry beacon. It uses FSK
modulation and if you chose GMSK it is several db improvement over FSK. The
antenna are turnstile with 2 db gain circular polarized. AO-51 keeps the
antennas nadir pointing so there is very little fading due to polarization
misalignments and this is a challenge on 10 cm cube.

If you make it to the cube sat conference at San Louis Obispo look me up I
am 6 ft tall with red hair and 64 years old.

Good luck
nick

-----Original Message-----
From: Yoon Ho Lee [mailto:yl482 at cornell.edu] 
Sent: Wednesday, April 15, 2009 9:18 AM
To: Nick
Subject: Re: [amsat-edu] Link Budget for Cornell University's student built
satellite Violet

Hello Nick,

It seems like the listserv denied my attachment. Here are the files.
Thank you for your interest and help!

-Danny

Nick wrote:
> Hi Danny
> I will review your link budget but it was not attached to your email.
>
> Please reply directly to this email off list
>
> nick
>
> -----Original Message-----
> From: amsat-edu-bounces at amsat.org [mailto:amsat-edu-bounces at amsat.org] 
> On Behalf Of Yoon Ho Lee
> Sent: Tuesday, April 14, 2009 7:12 PM
> To: amsat-edu at amsat.org
> Subject: [amsat-edu] Link Budget for Cornell University's student 
> built satellite Violet
>
> Dear whom it may concern,
>
> I'm Danny Lee from Cornell University's student built satellite team 
> Violet, working on Electrical Subsystem, specifically Telemetry and
Control.
> For those of you familiar with CUSat, our team is under the same UNP 
> program, on the 6th competition.
>
> I have worked out a preliminary link budget from limited resources and 
> knowledge, and I would greatly appreciate any input from experts out
there.
> Please read the note before proceeding to the spreadsheet.
>
> Thank you very much in advance, and I look forward to your input.
>
> Sincerely,
>
> Danny Lee
> Electrical Subsystem,
> Team Violet,
> Cornell University
>
>
>
>   





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