Re: [Xylo-SDR] Backplane stuff... Need input...

["Ray Anderson" <ray.anderson@xilinx.com>]

>Hi all,

>I have been playing around with a Vero protoboard and six 96 pin
>DIN41612 connectors this afternoon.  Here is what I came up with.

>For a board without provisions for card guides:

>3.94" W x 5.75" L    6 slots with 0.800" spacing

>For a board with card guides (such as Bivar which are 0.600" wide):

>5.00" W x 5.75" L   6 slots with 0.800 spacing

>Both are allowing for room on the ends for the ATX power supply style
>connector and some LEDs.

>Question:

>Do we want/need card guides?

>Pro:  Card guides will lock the boards in place.

>Con: By using card guides we restrict access to the side edges of the
>plug-in 3U100 boards.  We would only have clear access to the top
>edge.  There would also have to be a keep out area on the 3U100
>plug-in boards to accommodate the rail slots in the card guides.

>I am leaning towards recommending that we do not use card guides. 
>They are nice for longer boards, but for our 3U100 form factor I don't
>think we need them.

>73 de Phil C

Phil-

I'm glad you went through the exercise of physically checking the real
estate requirements. I was contemplating asking a question about size
and you've already answered it.

I don't really think board guides are mandatory for the small (100mm x
100mm) size boards envisioned. The resulting smaller backplane (with the
guides) will have the possibility of being used in a wider variety of
enclosures as well.

The small boards should be easy enough to plug in without guides and the
extra rigidity afforded by the guides probably isn't necessary for the
application at hand. (I suppose someone might want to go 4 wheelin' or
aero mobile and want to ensure the boards stay in place but that would
be the exception rather than the rule....)

-Ray	WB6TPU