[eagle] Re: Module Connectors

rjansson@cfl.rr.com rjansson at cfl.rr.com
Sat Jun 30 14:52:34 PDT 2007


Juan:

There just plain is not enough access on the sides of the module to 
make a connection to the SMA connectors, no withstanding that the 
aluminum cover would not be able to provide a mounting surface. It 
would also be some pretty ugly gymnastics with the cover in such a 
situation. I am sure that you can get four SMA connectors if you don't 
insist on their being PCB mounted. (I need to look again at John's 
drawings which are not with me at the moment.)

Take a look at my idea of a small cannister on top of the module with 
the CAN module inside.

'73,
Dick, KD1K

----- Original Message -----
From: Juan Rivera <juan-rivera at sbcglobal.net>
Date: Saturday, June 30, 2007 9:48 am
Subject: RE: [eagle]  Module Connectors
To: rjansson at cfl.rr.com, eagle at amsat.org

> Good morning Dick,
> 
> I agree that everything needs to be in one enclosure if at all humanly
> possible, but the front panel is badly blocked by the CAN-Do 
> circuit board.
> There just isn't enough room remaining to squeeze in the 4 SMA 
> connectorsthat are required for this receiver.
> 
> And if we need to go to a two-compartment enclosure configuration 
> to isolate
> the CAN-Do EMI from the analog receiver, running those four RF 
> lines in the
> back side of the CAN-Do compartment, and out the front is an 
> awkward design.
> Can you squeeze the four SMA connectors out the side if the 
> interconnectingcables are right angle style?  That would allow all 
> the RF to stay well
> clear of the CAN-Do EMI.
> 
> Juan
> 
> -----Original Message-----
> From: eagle-bounces at amsat.org [mailto:eagle-bounces at amsat.org] On 
> Behalf Of
> rjansson at cfl.rr.com
> Sent: Saturday, June 30, 2007 6:33 AM
> To: eagle at amsat.org
> Subject: [eagle] Mocule Connectors
> 
> John & Juan:
> 
> Your EMI problems certainly do present considerable difficulties. 
> Your 
> suggestions of placing connectors on multiple faces of a module 
> run 
> counter to the whole module mounting plan for Eagle. The modules 
> are 
> mounted with only about 1.5mm clearance at the flanges and only 
> about 
> 16mm clearance on the sides. The "rear end" of the module is also 
> difficult as there is just not that much space for cabling and 
> connector access. Mechanical designers in the past have been raked 
> over 
> the coals for not providing sufficient connector access. The 
> curren 
> plan allows about 100mm (I don't have the drawings with me at the 
> moment) of space between facing columns of modules for the cabling 
> and 
> connector access. This is a plan that is pretty basic to the whole 
> wiring plan for Eagle, and it is a result of a lot of experience 
> with 
> P3D.
> 
> While the basic module design for Eagle, unlike P3D, does not 
> provide 
> for the stacking of modules, a small CAN module placed on top of 
> the 
> URx, could be considered. Wiring to this sub-module would be by 
> means 
> of jumper leads from its connector face into the URx. 
> 
> I caution that there currently is not planned for much space above 
> the 
> rows of modules as the current spaceframe plan has the modules 
> placed 
> fairly closely under the solar panels. This concept is part of the 
> need 
> to keep the mass moment of inertia, Izz, high. This is NOT just a 
> desirable feature, but a necessary, MUST need for the spin 
> stability of 
> the spacecraft. So any top-mounted sub-module would have to not be 
> very 
> thick.
> 
> All of these issues arise from the practical considerations of the 
> overall mission of the spacecraft. Unfortunately for the EMI and 
> other "local" issues, we cannot design the spaceframe only for 
> EMI, but 
> must solve other mission requirements, too.
> 
> I am not trying to be unmovable on the design if the URx, but I am 
> trying to explain how we can have a successful mission.
> 
> '73,
> Dick, KD1K
> _______________________________________________
> Via the Eagle mailing list courtesy of AMSAT-NA
> Eagle at amsat.org
> http://amsat.org/mailman/listinfo/eagle
> 
> 


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