[Xylo-SDR] Comments on Board sizes & Eagle Light edition

[Don AE5K <don@ae5k.us>]

Thought I'd throw in a few comments after listening to the
xylo-teamspeak sessions and reading the talk on this reflector.

One of the standard size "Euro" PCB boards is 100 x 160 mm.
(This is approx. 3.9 x 6.3 inches).  Current thought for our project
seems to be a size of 4 x 2 inches (or 100 mm by 2 inches in a mixed
measurement system?)   We might consider making them just slightly
longer than the 2 inch dimension and if so, how about 80 mm? Then the
size would be exactly 1/2 of a standard Euro board size.  In other
words, make the board size 100 x 80 mm (approx. 3.9 x 3.15").

This also corresponds to the maximum size (how about that?) that the
free version of Eagle software will support.

With current thinking (the DIN connector along the 100 mm side), unless
you required front panel connection, the 80 mm dimension could be made
shorter/less to save on board cost if that much real estate was not needed.

Granted, maximum size we would support is based on some tradeoffs. Those
include cost of a little larger board (if needed for front panel
connection) vs. maybe using two smaller boards (with much added
connector cost plus longer signal paths) for a design.  My personal
preference is to put more on slightly larger boards and have fewer of
them, than to break it up onto smaller boards with more of them.

Now some comments on Eagle Light (the free version):
http://www.cadsoftusa.com/freeware.htm
is the web page which lists info about it.  As mentioned above, it is
limited to *generating* boards 100 x 80 mm, two layers, and the
schematic must fit on one page (but the page can be very large!).  That
is for *creating* -- it does have the capability of displaying or
printing all sizes which are created by the full Eagle package.

So if Eagle were used, those with the Light package could do a limited
amount of creation (including such things as library packages) to be
shared, but they could view and print anything greater than the
limitations (for instance 4 layer boards).  Those with the full package
would not have those limitations of course.

[Side note: I also happen to have the Professional full package
(legally) and agree that Eagle has a steep learning curve, but once
learned is one of the nicest systems around.  Support is very good, and
there is a large user support group too.  It is supported directly by
many PCB fab houses, not just the Gerbers etc it produces, but some will
even take the basic Eagle files.  I am not pushing use of Eagle, just
supplying some info about it.]

My 3 cents worth (inflation)...

73,
Don AE5K

-- 
Confidence is the feeling you have before you really understand the problem.