[eagle] Re: Receiver Spec vs. ATP, a few Suggestions and aQuestion or Two

[Juan Rivera]

Bdale,

It would be a trade-off.  I've put out all the information I have and
everyone knows my opinions.  I think someone else is supposed to be looking
into this but I forgot who it is since nothing has been posted.  I'd like to
see some alternative suggestions from the experts on the CAN-Do, the
enclosure, and the EMI situation in general.

By the way, do I have a prototype CAN-Do module or was the intent to fly
this version with the dead-bug step-down converter hanging by three leads
and a few wires?

Juan

-----Original Message-----
From: Bdale Garbee [mailto:bdale at gag.com] 
Sent: Saturday, July 28, 2007 2:41 PM
To: juan-rivera at sbcglobal.net
Cc: 'John B. Stephensen'; David Smith; Dave Black (Work); Dave Black (Home);
eagle at amsat.org; Samsonoff at Mac. Com; Juan.Rivera (Work)
Subject: Re: [eagle] Receiver Spec vs. ATP, a few Suggestions and aQuestion
or Two

On Fri, 2007-07-27 at 21:23 -0700, Juan Rivera wrote:

> I have a few thoughts...  The CAN-Do switching step-down converter is
> only supplying 11 milliamps.  If we take a slight efficiency hit we
> could just go to a simple linear regulator and completely eliminate
> the radiated and conducted EMI emission problem from CAN-do.  That
> eases the EMI filtering and shielding requirements for every single
> payload.  That seems like a good trade-off to me.

Hrm.  What makes you say "a slight efficiency hit"?  

Doing this on one or two modules that are particularly susceptible to
noise *may* make sense (and I'm certainly open to considering this as an
alternative), but we're already on our second power supply design on the
CAN-Do! because the original switcher, which was more efficient than a
linear regulator, was deemed too inefficient to fly on P3E by our
AMSAT-DL friends.

Bdale