Hub-0  Next Time List
              -----------------------

                                           Rev.  17-May-2017


The purpose of this file is to collect in one place all of
the things that I wish I had done differently in the Hub
Module design.  As usual, most of these things that I now
wish I had done differently were not recognized until I had
cards back from the assembly house and had worked with them
for a while.


1. I should have put tick marks on all of the high pin count
   components every 5 or 10 pins.


2. I need to change the thickness milling from the back side
   of the card to include milling the area where the Front
   Panel Handles mount so that the area around where the
   Handle screw goes through the card meets the maximum
   card thickness specification for the handle,  which is
   2.40 mm  with an absolute maximum of  2.60 mm.  The
   actual space available in the handle itself appears
   to be about  2.7 mm.


3. If the IPMC is not installed then there are no pull-up
   resistors on the Sensor I2C Bus,  e.g.  to run this bus
   from the Front Panel Access Connector  (unless the I2C
   "pod" that you are using includes pull-ups).


4. Just north and south of the U1 FPGA I could have mounted
   more large bypass capacitors  on just the top surface of
   the card.  These could not have been "high frequency"
   bypass because its is not possible to put vias close to
   these locations - but there is space for the component
   bodies to fit.  Some of this space has the height
   restriction of the FPGA heat sink fill block  but other
   areas could have accommodated components up to 8 mm high
   of so.  The electrical connections to any additional
   bypass capacitors in this area would need to be from
   vias perhaps  20 mm away but that would have been more
   or less OK for some bulk tantalum or aluminum polymer
   capacitors.   All space in this area should have been
   used.   No space is available on the bottom surface
   because of the Combined Data differential trace pairs
   in this area.