[hpsdr] Atlas orientation in Pandora...

[Warren C. Pratt]

Hi Isaac,

 

After seeing your post, I took some snapshots (quickly done, my apologies
for the photo quality) of my approach.  Temporary links provided:

 

http://dl.dropbox.com/u/9282924/HPSDR%202010-08-25.jpg

http://dl.dropbox.com/u/9282924/HPSDR%202010-08-25%20002.jpg

http://dl.dropbox.com/u/9282924/HPSDR%202010-08-25%20003.jpg

 

My objectives were:  (1) move the rats-nest of cables INSIDE the box so that
I could control grounding of everything exiting the box (to manage RF in a
QRO environment), and (2) arrange boards to allow a more "straight-through"
airflow for cooling.  I believe I've accomplished the objectives . with just
a couple other learning experiences along the way, the unit is working well
with my Alpha 89 amplifier.  Even though it's tight, Hercules does fit in
this Pandora.

 

You probably can't see it, but I added a small PC board that contains a DPDT
relay and a couple extra open-collector outputs for switching the external
amplifier and whatever else comes along in the future.  I'm also currently
working on a board layout to replace the LPU with the objectives of:  (1)
removing the +3.3 and -12 regulators that I don't use, (2) splitting the +5V
regulator heat between 2 heatsinks (parallel pass transistors), (3) adding
overvoltage protection, and (4) adding an "isolated" regulator to generate a
small amount of power for microphones that require it for lights, pre-amps,
etc.

 

I changed the feedback resistors on the Penelope output amp to reduce the
power output to drive Hercules.  (There are a couple other easy ways to deal
with this also.)

 

I think Pandora is an excellent experimenter's enclosure.  However, I'll
probably do a custom enclosure for my next version as my objectives are
somewhat different.

 

Warren, NR0V

 

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