Dick,
You could be
correct although I wouldn’t call it butchered. I enlarged the holes
using my milling machine, a few thousandths of an inch at a time. But
aside from the altered state of this base plate I think there are other issues
to address. It may come to pass that two compartments are required to
deal with the radiated EMI from the CAN-Do module. I think it will be
very hard to partition this enclosure into two RF-tight compartments using
sheet metal. I also think the AVX guide specifying no more than 0.0038”
flex in any one-inch segment of the PCB might be hard to meet with this
enclosure. AVX is one of the largest manufacturers of ceramic chip
capacitors in the world so I believe they know what they are talking
about. If anyone disagrees and wants to put out another argument for
maximum SMT PCB flex I’d be interested to see it.
Anyway my
opinions are just that. Once the dust settles and there is an EMI
requirement and a PCB flex requirement, a determination can be made to see if
the existing enclosure meets the requirements. If it does then there is
no need to change it. That removes all the subjective opinions out of the
decision loop. You hold everything up to the peer-reviewed requirements,
run some peer-reviewed tests, and either it passes of it fails. The same
goes for the CAN-Do module and the Receiver. At least that’s the
way I’m used to doing things at work.
73,
Juan
From: Dick Jansson-rr
[mailto:[email protected]]
Sent: Tuesday, July 17, 2007 11:36
AM
To: 'Juan Rivera'; 'Chuck Green'
Cc: 'David Smith'; 'Dave Black
((Work))'; 'Dave Black ((Home))'; 'Louis McFadin'; 'AMSAT Eagle'; 'Samsonoff@Mac.
Com'; 'Juan.Rivera ((Work))'
Subject: RE: [eagle] Re: CAN-Do
Suggestions from Juan
Juan:
You keep commenting on the flexure of the
PCB and relate it to the module hardware that you have in hand. It is my very
greatly considered opinion that the baseplate that you have has been modified
(butchered) to allow for the soldering of the CAN 40pin connector and this has
created not only reduced sections in this plate, but probably has also
distorted the plate considerable. Such distortions in all likelihood have
created a non-normal flexure condition in that particular plate. As such, your
opinion of the design has been biased, and that is unfortunate. It seems to me
that you should try to acquire an E05 21 base plate that is in “stock”
condition. I don’t have any in hand here in
’73,
Dick Jansson, KD1K