[hpsdr] Pandora

Tue May 22 16:51:19 PDT 2007

Jason 

And all who have commented on Atlas and Case but who may not have been
around last year when Atlas was designed.

Perhaps for folks who have recently joined, there is a mis-conception about
Atlas. It was VERY carefully designed and discussed, went through 2 alpa's
and was thoroughly VNA tested and shown to be as good as a 6 layer board
with 2 ground planes. It WAS designed to go in a PC enclosure due to card
spacing, however it was designed also at the time to be 2u EuroCard and you
will find that it is dimensioned as such. It is NOT ATX compatible with AT
or ATX mounting holes or standoff's! Jason you will have to use brass hex
standoffs or washers to mount in any case. (The structural kick in your
picture worries me about minimum height clearance). For folks using computer
enclosures you WILL have to experiment with the number and thickness of
washers or brass standoffs. Also the setback of the board etc. Please
publish your design and findings, which will probably be experimental.

The number of slots is really a poor choice for a 'fixed' re-design, and is
more preference. If we took a vote on number of slots we would probably come
up with 1 to 10 averaging 5. If we produce AtlasLite, which is a fine
design, with 2 slots, then we will probably have to produce AtlasLite3 with
3 slots for Ozy-Pen-Merc (errr maybe 4 slots in case this tranciever needs a
buss mounted filter) ---- and so on to 10 slots or so for multiple receivers
and transmitters.

Six slots which Phil Covington - N8VB, the designer produced is a good
median. It was his choice alone since he laid out the board which we
produced and continue to produce. In Lyle's presentation he is absolutely
correct. The Project leader takes suggestions, incorporates, takes
suggestions, does not incorporate, takes suggestions and incorporates, then
when HE is happy, says "I'm done" and it goes to copper! Phil did JUST THAT
and did incorporate great suggestions and produced a great design. (IMHO). 

Atlas Lives! If there is to be another backplane it should be a quantum leap
in design, not just more or less slots. Perhaps with an SBC or embedded
Linux computer, or?????? We just need another project leader and a concept
design.

Perhaps Jason can post design files for each number of slots, it only takes
3 folks and no-touch board mfgr to make 3 at about $51 bux per to get them
made in 10 days. Still pretty cheap!

For the moment. Since the 11 dollar cost of a board is seen as trivial in
re-design terms, perhaps someone SHOULD try cutting the board down with a
diamond saw! I think that it is theoretically possible.

Or someone could design a 'lego' modular design with the power connector and
1 slot and a stack plane of daughter boards for 1 to the N connectors, as
mini-kits. Put the Din connector at right angles to a 96 pin .1 space dip
connector with male posts on one side female on the other.

Many great ideas.

Thanks
Eric

-----Original Message-----
From: hpsdr-bounces at hpsdr.org [mailto:hpsdr-bounces at hpsdr.org] On Behalf Of
Jason Hitesman
Sent: Tuesday, May 22, 2007 4:18 AM
To: hpsdr at hpsdr.org
Subject: Re: [hpsdr] Pandora

***** High Performance Software Defined Radio Discussion List *****

As I mentioned earlier in this thread I started looking into using an
existing PC case for my HPSDR collection.  However I found that there
are some mounting issues.

I finally got around to snapping a few photos to show what I found today:

This is the removeable rack from the case I was favoring.  It's the
easiest to demonstrate with since there are no sides to block the
view.  However the problems it has with stock mounts/locations were
common to all four cases I experimented with.

http://jhitesma.smugmug.com/photos/155034269-M.jpg

Here it is with Atlas resting inside.  The atlas was aligned with the
two stock mounting holes...but pulled back from the edge to show how
it lines up with them.  And because I still had risers on the board so
it wouldn't go directly over the stock mounts:

http://jhitesma.smugmug.com/photos/155034577-M.jpg

And now with Ozy in an arbitrary slot.  Notice I had to move it
further back (so the stock mounts weren't any help) and even though
the spacers I have on the atlas are the same height as the stock
mounts...the whole thing is sitting too high:

http://jhitesma.smugmug.com/photos/155034758-M.jpg

Here's a better view of how high the atlas/ozy combo sits mounted on
the same standoffs that were used with a motherboard:

http://jhitesma.smugmug.com/photos/155034941-M.jpg

And finally a side view again showing the height issue:
http://jhitesma.smugmug.com/photos/155035176-M.jpg

(Yes, the standoffs I'm using are a little bit higher since they were
designed to clip into the case...but they still sit about the same and
even with the molded in mounts the atlas still sits too high for the
USB port to be accessible.)

So like I said before...if I want to use a PC case it looks like I'll
have to cut the base out and make a new base that sits a little lower.

Has anyone else had better luck fitting this into a PC case?

----
Jason Hitesman
N8INJ
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